What Is Spirulina? Nutrition, Phycocyanin, Human Research, Safety & Skincare — The Complete Guide

“So, what exactly is spirulina?”

If you are interested in health, nutrition or beauty, you have probably come across the name spirulina alongside the word “superfood.”

Best known as a deep blue-green powder or tablet, spirulina contains a wide variety of components within a single natural material, including protein, essential amino acids, minerals, carotenoids, and the vivid blue pigment phycocyanin.

But the more closely you look at spirulina, the more you discover that it is far more fascinating than simply being a “nutrient-rich green food.”

For example:

• Is spirulina a plant, an alga, or something else entirely?
• Why is it biologically classified as a cyanobacterium?
• What is the difference between the names Spirulina, Arthrospira and Limnospira?
• Why can such a large proportion of its dry weight be protein?
• What do blue phycocyanin and green chlorophyll actually do?
• How is spirulina different from chlorella and euglena?
• How should we understand its vitamin B12-related compounds?
• How far has human research progressed in areas such as allergic rhinitis, blood lipids, blood pressure, body composition and the gut?
• And why is an ingredient best known as a food also used in skincare and cosmetic research?

Each answer seems to open the door to another question.

Today, spirulina is being studied for much more than its role as a food on Earth. Because it can produce biomass, use carbon dioxide and release oxygen through photosynthesis, researchers are also exploring its potential role in supporting future long-duration space living.

In this complete guide, we will explore spirulina from multiple angles: its biological identity, nutritional composition, natural pigments, differences from chlorella and euglena, human research, cosmetic applications and safety.

The goal is simple: to give you one in-depth article that helps you truly understand spirulina.

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1. What Is Spirulina? Algae-Like, but Actually a Cyanobacterium

Spirulina is often introduced as a type of “blue-green algae” or “microalgae.”

It grows in water, performs photosynthesis and looks very much like an alga. But from a biological perspective, this is where the story becomes especially interesting.

A Photosynthetic Cyanobacterium

Spirulina belongs to a group of organisms known as cyanobacteria.

Cyanobacteria were historically called “blue-green algae,” which is why spirulina is still commonly described using terms such as blue-green algae or microalgae.

One of the most important differences lies in cell structure.

Many familiar algae, including chlorella, are eukaryotic organisms, meaning their cells contain a nucleus surrounded by a membrane.

Cyanobacteria, in contrast, are prokaryotic organisms and do not have a membrane-bound nucleus.

So spirulina has an unusual biological identity:

It grows in water and performs photosynthesis like an alga,
yet biologically it belongs to the cyanobacteria—a group of bacteria.

Understanding this distinctive position is the first step towards understanding spirulina itself.

Cyanobacteria in the History of Life on Earth

Looking even further back, cyanobacteria are among the most important groups of organisms in the history of life on Earth.

They carry out oxygenic photosynthesis, using light energy while releasing oxygen.

Over immense periods of geological time, photosynthetic microorganisms such as cyanobacteria are thought to have played a major role in the gradual rise of oxygen in the oceans and atmosphere.

Learning about spirulina therefore connects us with something much larger than a single food ingredient: the extraordinary history of photosynthetic microorganisms and their relationship with the planet itself.

Spirulina, Arthrospira and Limnospira — Why Are There Three Names?

When reading scientific literature about spirulina, you may encounter several different names:

• Spirulina
• Arthrospira
• Limnospira

This reflects how biological classification has evolved.

Earlier classification relied heavily on visible characteristics and morphology. As DNA analysis, molecular biology and genome-based classification advanced, scientists were able to examine relationships between these organisms in greater detail.

Several commercially important strains historically known as Arthrospira platensis, Arthrospira maxima and Arthrospira fusiformis have more recently been placed mainly within the genus Limnospira.

At the same time, the word “Spirulina” has become firmly established around the world as the familiar name used for foods and supplements.

For clarity and readability, this article therefore uses the widely recognised common name “spirulina.”

The Name Comes From Its Spiral-Like Shape

The name spirulina is associated with its distinctive shape.

Under a microscope, its long filament-like cells can form spiral or coil-like structures resembling tiny springs.

That image is very different from the dark blue-green powder most people see in shops, but once you see the microorganism itself, the connection with the word “spiral” becomes easy to understand.

A Cyanobacterial History Reaching Back Billions of Years

Cyanobacteria belong to an extremely ancient group of organisms.

Scientists continue to study microbial evidence extending back roughly 3.5 billion years, as well as the evolution of oxygen-producing photosynthesis and its relationship with changes in the Earth’s environment.

This does not mean that the Limnospira used as food today has existed unchanged for 3.5 billion years.

Rather, the number helps us appreciate the extraordinary evolutionary history of the cyanobacterial group to which spirulina belongs.

Mexico and Africa — A Food Tradition Across Distant Cultures

Spirulina also has a fascinating history as a human food.

In 16th-century Mexico, historical accounts describe the Aztecs and other communities collecting blue-green material from Lake Texcoco and preparing a dried food known as “tecuitlatl.”

Far away in Africa, communities around Lake Chad—particularly the Kanembu people— have also traditionally collected spirulina and dried it into a food known as “dihé.”

Mexico and Africa are separated by enormous geographical and cultural distances, yet people in both regions developed ways of using these blue-green microorganisms as food.

That parallel history is one of the most intriguing parts of the spirulina story.

And in 2026, Spirulina Research Reached Space

Today, spirulina research extends far beyond Earth.

Because it performs photosynthesis, spirulina can potentially be studied for its ability to:

• produce edible biomass
• use carbon dioxide
• release oxygen
• grow in relatively compact cultivation systems

These characteristics make it especially interesting for research into closed environments.

In 2026, JAXA conducted the “Space Surface Spirulina” experiment aboard the Japanese Experiment Module “Kibo” on the International Space Station (ISS).

Rather than relying on a conventional cultivation tank filled with large volumes of water, the experiment investigated a method of growing spirulina across the surface of a supporting material.

If future cultivation systems can use limited water and space to produce protein-containing biomass while also contributing to carbon dioxide processing and oxygen production, they could potentially become useful technologies for long-duration human space missions.

A food once harvested from lakes is now being investigated as part of future food-production and life-support systems beyond Earth.

That connection between ancient food traditions and the future of human life in space is one of the most remarkable aspects of spirulina.

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2. Why Is Spirulina Called a Superfood? A Closer Look at Its Nutrition

One word frequently associated with spirulina is “superfood.”

“Superfood” is a popular term used to highlight foods with interesting nutritional characteristics.

So why has spirulina attracted so much attention?

The best way to understand its appeal is not to focus on one single nutrient, but to recognise that many different nutrients and natural pigments coexist within one tiny organism.

What Is Found in Dried Spirulina?

The exact composition varies according to species, cultivation conditions, harvest timing and processing, but dried spirulina generally contains substantial amounts of protein, carbohydrates, lipids and minerals.

Main Component	Approximate Share of Dry Weight	Key Feature
Protein	About 60–70%	Contains essential amino acids
Carbohydrates	About 15–20%	Includes polysaccharides
Lipids	About 5–8%	Includes fatty acids such as gamma-linolenic acid
Minerals	About 6–8%	Includes iron, magnesium and other minerals

It also contains components such as:

• phycocyanin
• chlorophyll a
• carotenoids such as beta-carotene
• pigments such as zeaxanthin
• a variety of amino acids

This multi-layered composition is one of the main reasons spirulina is such an interesting nutritional material.

Protein Can Account for Around 60–70% of Dry Weight

One of spirulina’s most striking nutritional characteristics is its high protein proportion.

Depending on cultivation and processing, around 60–70% of its dry weight may consist of protein.

That protein also contains essential amino acids— amino acids that humans need to obtain through food.

With High-Protein Foods, Look at Both Percentage and Serving Size

An important way to understand spirulina is to look at both the protein percentage and the amount actually consumed.

If we assume a protein content of roughly 60–70%:

• 3 g of spirulina provides about 1.8–2.1 g of protein
• 5 g of spirulina provides about 3–3.5 g of protein

So while the percentage of protein in dried spirulina is very high, the total amount consumed in a typical serving is usually only a few grams.

When aiming for larger amounts of daily dietary protein, foods such as meat, fish, eggs, dairy products and legumes remain important parts of the overall diet.

Spirulina is best understood as a distinctive food material that combines protein with a wide range of other nutritional components.

It Contains All Nine Essential Amino Acids

Spirulina protein contains the essential amino acids:

• leucine
• isoleucine
• valine
• lysine
• methionine
• phenylalanine
• threonine
• tryptophan
• histidine

Amino acids are the building blocks of proteins used throughout the body, including proteins found in muscles, skin and enzymes.

Individual amino acids also participate in different metabolic pathways.

For example, tryptophan is involved in metabolic pathways leading to compounds such as serotonin.

Phenylalanine can be converted to tyrosine, which in turn participates in pathways associated with catecholamine synthesis.

Dietary amino acids are digested and absorbed, then used alongside other amino acids and nutrients within a complex network of metabolism throughout the body.

Iron and Other Minerals

Spirulina also contains several minerals, including iron, magnesium, potassium and calcium.

Iron receives particular attention.

It is an essential mineral required for normal functions including the formation of haemoglobin, which helps transport oxygen in the blood.

When evaluating any food as a source of minerals, it is helpful to look at both the amount per 100 g and the amount actually consumed in a typical serving.

Iron status is also influenced by factors such as the form of iron, the rest of the diet and an individual’s nutritional status.

Spirulina can therefore be viewed as one of many foods that contribute iron and other minerals to the diet.

Carotenoids Such as Beta-Carotene

Spirulina contains carotenoids including beta-carotene.

Beta-carotene is a naturally occurring yellow-orange pigment. The body can convert it into vitamin A as needed.

Vitamin A is an essential nutrient involved in normal functions of the skin, mucous membranes and vision.

Other carotenoids found in spirulina, including zeaxanthin, have also been studied.

Blue phycocyanin.
Green chlorophyll.
Yellow-orange carotenoids.

Spirulina is actually a food containing several different colours within the same organism.

Gamma-Linolenic Acid (GLA)

Spirulina is not especially high in total fat compared with its protein content, but its fatty-acid profile includes gamma-linolenic acid (GLA).

GLA is an 18-carbon polyunsaturated fatty acid.

Looking beyond protein, pigments and minerals to the types of fatty acids present helps reveal an even more complete picture of spirulina’s composition.

Vitamin B12: Both the Amount and the Form Matter

One of the most interesting details in spirulina nutrition concerns vitamin B12-related compounds.

Some analytical methods detect compounds in spirulina that may be measured as vitamin B12.

However, studies examining their chemical structures in greater detail have reported that a major B12-related compound is pseudo-vitamin B12, an inactive B12 analogue.

This illustrates an important nutritional principle:

It is useful to ask not only “how much is detected?”
but also “is it present in a form that the human body can use as vitamin B12?”

For people following vegan or vegetarian diets, where reliable dietary sources of vitamin B12 may be limited, it is particularly important to obtain B12 from well-established sources such as appropriately fortified foods or B12 supplements.

Spirulina’s Appeal Is the Diversity Within One Small Organism

Spirulina contains a remarkable combination of:

• a high proportion of protein
• essential amino acids
• minerals
• fatty acids
• carotenoids
• chlorophyll
• phycocyanin

Its distinctive quality lies in the fact that many different nutrients and natural pigments coexist within one tiny organism.

That helps explain why spirulina has remained a subject of food and nutritional research for so many years.

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3. Blue Phycocyanin & Green Chlorophyll — The Secrets Behind Spirulina’s Colour

For many people, the first memorable feature of spirulina is its deep blue-green colour.

But look more closely, and that colour turns out to be a combination of blue, green and yellow-orange natural pigments.

Phycocyanin — Spirulina’s Striking Blue Pigment

One of the most distinctive is phycocyanin.

Phycocyanin is a blue pigment-protein found in cyanobacteria and related organisms.

It is more than simply a colouring molecule. Its pigment component is associated with protein and participates in the transfer of light energy during photosynthesis.

Cyanobacteria contain structures called phycobilisomes, which help capture light.

Phycocyanin is one of their key components, helping absorb wavelengths of light and transfer that energy towards the photosynthetic system.

To us it appears as an extraordinary blue colour. For spirulina, it is part of an elegant system for making efficient use of sunlight.

“Spirulina Blue” Comes From Phycocyanin

When phycocyanin is extracted from deep blue-green spirulina, the resulting colour can be remarkably vivid blue.

This property has led to its use as a naturally derived blue food colouring in products such as confectionery, beverages and desserts.

If you see the term “spirulina blue,” phycocyanin is usually the star behind that colour.

Chlorophyll a — The Green Pigment at the Heart of Photosynthesis

Another major pigment is chlorophyll.

Spirulina primarily contains chlorophyll a, which plays a central role in photosynthesis by helping convert light energy into chemical energy.

Because chlorophyll is also widely found in plants, many people naturally associate it with the colour green.

Phycocyanin helps collect light energy, that energy is transferred through the photosynthetic system, and chlorophyll plays a central role in the photochemical reactions.

Seen this way, spirulina’s blue and green colours are connected not only with appearance, but with the biological machinery of photosynthesis itself.

Carotenoids Such as Beta-Carotene and Zeaxanthin

Spirulina also contains carotenoids such as beta-carotene and zeaxanthin.

Carotenoids form a group of pigments typically associated with yellow to orange colours.

So within spirulina we find:

• Phycocyanin → blue
• Chlorophyll a → green
• Carotenoids → yellow to orange

These different pigments coexist in the same organism.

The characteristic deep blue-green colour we see is therefore partly the visual result of multiple photosynthetic pigments overlapping together.

Phycocyanin Is Also an Active Research Material

Research into phycocyanin extends beyond its striking colour. Scientists have also examined its molecular characteristics in a wide range of basic research.

In laboratory, cellular and animal studies, researchers have investigated areas including:

• reactions associated with oxidation
• signalling pathways associated with inflammation
• cellular signalling
• immune-related biological responses

One useful way to read this type of research is to ask what stage of evidence the study represents.

The phrase “research has shown” can mean very different things depending on which of these stages is being discussed.

What was used? Who or what was studied? What was actually measured?

Keeping those questions in mind makes research on spirulina—and food ingredients in general— much easier to understand in context.

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4. Spirulina vs Chlorella vs Euglena — What Is the Difference?

Two names often mentioned alongside spirulina are chlorella and euglena.

All three can appear as green powders or nutritional products, so at first glance they may seem closely related.

Biologically, however, they represent very different types of organisms.

Feature	Spirulina	Chlorella	Euglena
Classification	Cyanobacteria	Green algae	Euglenids
Cell Type	Prokaryotic	Eukaryotic	Eukaryotic
Nucleus	No membrane-bound nucleus	Present	Present
Typical Shape	Filamentous / spiral	Small and spherical	Elongated single cell
Movement	Some forms show gliding or rotating movements	Generally non-motile	Moves using a flagellum
Main Pigments	Phycocyanin, chlorophyll a, carotenoids	Chlorophyll a & b, carotenoids	Chlorophyll a & b, carotenoids
Characteristic Component	Phycocyanin	Chlorophyll and other algal components	Paramylon

Spirulina and Chlorella — Different at the Cellular Level

Chlorella belongs to the green algae and is a eukaryotic organism, meaning its cells contain a nucleus and other membrane-bound structures.

Spirulina, by contrast, is a cyanobacterium and therefore a prokaryotic organism.

So:

Although spirulina and chlorella may both appear as “green nutritional foods,” their fundamental cellular organisation is different.

Their pigments also differ.

Chlorella prominently contains chlorophyll a and b, whereas spirulina contains chlorophyll a together with the striking blue pigment phycocyanin.

Euglena — A Unique Single-Celled Organism

Euglena is a distinctive single-celled organism with a very different biology again.

It contains chloroplasts and can perform photosynthesis, while also using a flagellum to move through water.

Another characteristic component of euglena is paramylon.

Paramylon is a storage polysaccharide made primarily of beta-1,3-glucan, which euglena uses as an energy reserve.

Understanding the Differences Makes These Foods More Interesting

Spirulina, chlorella and euglena each have their own biological background and characteristic components.

Spirulina → phycocyanin.
Chlorella → green-algal cell structure and chlorophyll.
Euglena → flagellar movement and paramylon.

Foods that look similar on the outside can represent completely different biological worlds on the inside.

Understanding those differences gives us a much more useful way to compare and appreciate these materials.

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5. Spirulina Research — What Has Been Studied in Humans?

We now come to one of the most interesting areas of spirulina science: research involving human participants.

Human studies have explored a surprisingly wide range of topics, including:

• symptoms associated with allergic rhinitis
• blood lipid markers
• blood pressure
• glucose and insulin-related metabolic markers
• body weight, BMI and body-fat measurements
• gut-related outcomes
• spirulina used alongside exercise programmes

Four Things to Check When Reading Human Research

When reading nutrition research, the headline result is only part of the story.

Four questions make a study much easier to understand:

• Who participated in the study?
• How much spirulina was used each day?
• How long did the study last?
• What outcomes were actually measured?

Was the study conducted in healthy adults, or in people with a specific medical condition?

Did participants use 1 g, 2 g or several grams per day?

Did the study run for a few weeks or several months?

Were the outcomes based on questionnaires, blood tests, physical measurements, or several types of assessment together?

Checking the participants, amount, duration and measured outcomes helps put each result into its proper context.

Allergic Rhinitis — Randomised Trials Measuring Nasal Symptoms

Allergic rhinitis is one area in which spirulina has been investigated in human clinical research.

A randomised, double-blind, placebo-controlled trial published in 2008 enrolled 150 people with allergic rhinitis.

Researchers compared spirulina with placebo and assessed symptoms and clinical findings including:

• nasal discharge
• sneezing
• nasal congestion
• itching

Differences between groups were reported for several measured outcomes.

In 2020, another clinical study compared spirulina with the antihistamine cetirizine in people with allergic rhinitis.

These studies show that spirulina and allergic rhinitis have progressed beyond laboratory research into human clinical investigation.

For anyone experiencing allergic-rhinitis symptoms, medical diagnosis and appropriate treatment remain the foundation of care. These findings are best understood as part of the wider field of food and nutrition research.

Blood Lipids — A Meta-Analysis of 20 Studies and 1,076 Participants

Blood lipid markers are among the more extensively studied areas of spirulina research.

A 2023 systematic review and meta-analysis of randomised controlled trials combined data from 20 studies involving 1,076 participants.

The main outcomes included:

• total cholesterol (TC)
• LDL cholesterol (LDL-C)
• triglycerides (TG)
• HDL cholesterol (HDL-C)

In the pooled analysis, statistical differences between the spirulina and control groups were reported in directions including lower TC, LDL-C and TG, and higher HDL-C.

The trials included participants with different health backgrounds, ages, intake levels and intervention durations.

That is why it is useful to look beyond the headline result and ask which populations and study conditions were included in the analysis.

Blood Pressure — Also Examined in a GRADE-Assessed Meta-Analysis

Randomised trials have also investigated blood pressure.

A GRADE-assessed systematic review and meta-analysis published in 2025 combined several adult clinical trials.

On average, the pooled analysis reported between-group differences in the direction of approximately:

• 4.4 mmHg lower systolic blood pressure
• 2.8 mmHg lower diastolic blood pressure

The authors rated the overall certainty of evidence as moderate.

Blood pressure is influenced by many factors, including diet, body weight, physical activity, sleep, alcohol intake, smoking and medical treatment when required.

Spirulina can therefore be understood as one nutritional intervention being studied within that much broader context.

Weight, BMI & Body Fat — A 2025 Meta-Analysis of 17 RCTs

Body-composition research has also expanded.

A 2025 meta-analysis included 17 randomised controlled trials.

Across the pooled studies, average between-group differences were reported in the direction of approximately:

• 1.07 kg lower body weight
• 0.40 lower BMI
• 0.84 percentage points lower body-fat percentage

Waist circumference showed a different overall pattern in the pooled analysis.

These results are interesting because they show that spirulina research has assessed several measurements of body composition, not simply body weight alone.

Body-weight management is influenced by total dietary intake, physical activity, muscle mass, sleep and many other lifestyle factors.

Spirulina continues to be studied as one component within broader nutrition and lifestyle research.

Blood Glucose & Insulin — The Study Population Matters

Blood glucose and insulin-related markers have also been investigated.

This area provides a particularly good example of why the characteristics of the study population matter.

Some analyses of trials involving people with type 2 diabetes have reported between-group differences in measures such as fasting blood glucose.

Other analyses focusing on adults with overweight or obesity have produced different findings for fasting glucose and insulin-related outcomes.

So when reading research about “spirulina and blood glucose,” it is important to ask who was actually included in the studies.

That context helps us understand why different analyses may reach different conclusions.

The Gut — A 2025 Trial in Constipation-Predominant IBS

Research into spirulina and gut-related outcomes has also become increasingly specific.

In 2025, a randomised, double-blind, placebo-controlled trial included 60 people with constipation-predominant irritable bowel syndrome (IBS-C).

Participants received 1 g of spirulina per day or placebo for 12 weeks.

Researchers assessed outcomes including:

• quality of life
• IBS severity scores
• markers related to intestinal permeability
• markers associated with oxidative stress
• inflammation-related markers

Between-group differences were reported for several of the measured outcomes.

This illustrates how the broad topic of “spirulina and the gut” is now being investigated through specific, measurable clinical endpoints.

IBS-C is a medical condition, so research findings should be interpreted within the conditions of the study. People with ongoing gastrointestinal symptoms should seek appropriate medical assessment and care.

Dietary Fibre Is Best Considered as Part of the Whole Diet

Spirulina contains dietary fibre and polysaccharides.

When only a few grams of spirulina are consumed per day, however, dietary fibre intake still comes mainly from a broad range of everyday foods such as:

• vegetables
• fruit
• legumes
• whole grains
• mushrooms
• sea vegetables

Spirulina fits naturally as one distinctive food within a varied diet.

Spirulina Has Also Been Studied Alongside Exercise

Because spirulina is a protein-rich food material, researchers have also investigated it in combination with exercise.

Recent studies and reviews have examined outcomes such as:

• body composition
• lipid-related markers
• glucose-related markers
• blood pressure
• cardiorespiratory fitness

In this context, spirulina is being studied as a food material containing not only protein, but also pigments, fatty acids, minerals and other components.

Iron, Sleep, Fatigue, Alcohol & Hair — How to Read These Topics

Because spirulina contains many different nutrients, it is often discussed in connection with a wide range of health topics.

A useful way to organise this information is to separate the biological roles of nutrients contained in spirulina from human research evaluating spirulina itself.

Topic	How to Understand the Nutrients & Research
Iron & Anaemia	Spirulina contains iron and protein. Iron is an essential nutrient required for normal red-blood-cell and haemoglobin formation. Because anaemia can have many different causes, symptoms or abnormal blood-test results should be properly assessed.
Sleep	Spirulina contains tryptophan. Tryptophan participates in metabolic pathways associated with serotonin and melatonin. When looking at sleep, it is useful to distinguish the biochemical role of tryptophan from human studies that directly measure sleep-related outcomes.
Fatigue & Exercise	Spirulina contains amino acids and pigment compounds, and some studies have measured various exercise-related outcomes. Participants, exercise conditions, duration and measured endpoints all help determine how each study should be interpreted.
Alcohol / Hangover Topics	Spirulina contains amino acids, fatty acids and minerals. The way a person feels after drinking alcohol is also influenced by alcohol intake, hydration, food and sleep, so the nutritional composition of spirulina and research on alcohol-related outcomes should be considered separately.
Hair	Protein and amino acids are building blocks used throughout the body. When considering hair and scalp health, it is helpful to look at the overall diet—including nutrients such as protein, iron and zinc—alongside research specifically designed to evaluate hair or scalp outcomes.

Research becomes much easier to understand when followed in this order:

Nutrient or compound → biological role → basic research → human research

This helps answer two very different questions: “What does this component do biologically?” and “What has actually been measured in humans?”

It is a useful way to read not only spirulina research, but also information about many other foods, supplements and cosmetic ingredients.

 

 

6. Beyond Food: Spirulina in Beauty & Skincare

So far, we have mainly explored spirulina as a food.

Another fascinating aspect of spirulina is that it is also used as an ingredient in cosmetics and skincare.

In the cosmetic field, research and product development have explored areas such as:

• spirulina-derived extracts
• various spirulina-derived components
• pigment compounds such as phycocyanin
• cosmetic formulations containing microalgae-derived ingredients

The Same Spirulina, but a Different Perspective in Food and Cosmetics

When spirulina is considered as a food, attention is usually given to components such as protein, amino acids, fatty acids, minerals and carotenoids— components consumed as part of the diet.

When spirulina-derived ingredients are used in cosmetics, they are instead evaluated as cosmetic ingredients applied to the surface of the skin.

So although the name “spirulina” is the same, the way it is used and the way it is researched are different in food and cosmetic applications.

Understanding this distinction makes it easier to see why spirulina has found applications ranging from nutrition to beauty and skincare.

Microalgae Are Also Being Studied as Cosmetic Ingredients

Microalgae and cyanobacteria, including spirulina, contain a variety of substances such as pigments, proteins, amino acids and lipids.

In cosmetic and dermatological research, formulations containing microalgae-derived ingredients have been evaluated using measures such as:

• skin moisture
• TEWL (transepidermal water loss)
• skin-surface characteristics
• keratinocytes
• fibroblasts

TEWL, or transepidermal water loss, is a measure of how much water passes from the skin to the external environment.

If we imagine skin moisture as the water stored inside a tank, TEWL can be thought of as the water gradually leaving that tank.

Cosmetic research uses measurements such as these to evaluate the skin surface and specific cosmetic formulations under defined study conditions.

A New Zealand Combination: Spirulina × Thermal Mud

Spirulina is best known as a food ingredient, but it can also appear in some rather unexpected skincare combinations.

One example is:

NB Rotorua Natural Mud Face Mask 200g

Rotorua, located on New Zealand’s North Island, is one of the country’s best-known geothermal regions, famous for geysers, hot springs, steam vents and bubbling mud pools.

This face mask combines Rotorua thermal mud with spirulina-derived ingredients.

Rotorua Thermal Mud, Bentonite & Kaolin

The face mask contains clay and mud ingredients including:

• Rotorua thermal mud
• bentonite
• kaolin

Applied to the skin and then rinsed away, the mask helps wash away excess surface oil and impurities associated with old surface skin cells, leaving the skin feeling clean, refreshed and smooth.

The use of Rotorua thermal mud also gives the product a distinctly New Zealand character.

Also Formulated With Spirulina, Royal Jelly & Vitamin E

The formula also combines:

• Spirulina — used as a skin-conditioning ingredient
• Royal Jelly — used to help moisturise and condition the skin
• Vitamin E — used as a cosmetic ingredient to help keep the skin in good condition

Together with Rotorua mud and clays, these naturally derived cosmetic ingredients create a rinse-off mask designed to leave the skin feeling fresh and well cared for.

From Food to Beauty — Another Side of the Same Natural Material

Throughout this guide, we have looked at spirulina as:

• a cyanobacterium
• a protein-rich food material
• a source of the pigment phycocyanin
• a subject of nutrition and human research
• a cosmetic ingredient

One natural material can be used in very different ways across food and skincare.

That breadth of use is another reason spirulina is such an interesting material to explore.

Enjoy a Rotorua-Inspired Home Spa

The mask is simple to use.

After cleansing, apply an even layer to clean skin, avoiding the eye area.

Leave it on for approximately 15–20 minutes, then rinse thoroughly with lukewarm water.

Follow with your usual skincare routine, such as toner, serum and face cream.

It can be a relaxing addition to your skincare routine— perhaps while reading a book or enjoying a cup of tea— and a simple way to bring a touch of New Zealand’s geothermal landscape into your beauty ritual.

View NB Rotorua Natural Mud Face Mask 200g →

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7. Natural Complex Nutritional Materials: Royal Jelly, Grape Seed & Bilberry

Looking closely at spirulina reveals another useful way to think about natural foods.

Rather than focusing on only one famous compound, we can also look at the wider combination of components naturally present within the material itself.

Part of Spirulina’s Appeal Is Its Complex Composition

As we have seen, spirulina naturally contains a variety of components, including proteins, amino acids, fatty acids, minerals, carotenoids, phycocyanin and chlorophyll.

Different types of compounds coexist within a single organism.

Once we begin looking at natural materials in this way, other foods with very different origins become equally fascinating.

Spirulina & Royal Jelly — Two Natural Materials With Very Different Origins

One interesting example is royal jelly.

Spirulina and royal jelly are natural materials created in completely different ways and with different compositions.

Spirulina is a photosynthetic cyanobacterium.

Royal jelly, by contrast, is produced by worker bees and serves as the characteristic food of queen bees.

Despite their very different origins, both can be viewed as complex natural materials containing a variety of naturally occurring components.

Royal jelly contains components including:

• proteins and peptides
• amino acids
• lipids
• carbohydrates
• vitamins
• minerals
• 10-HDA (10-hydroxy-2-decenoic acid)

10-HDA — A Characteristic Component of Royal Jelly

One particularly distinctive compound in royal jelly is 10-HDA (10-hydroxy-2-decenoic acid).

10-HDA is one of the characteristic fatty acids found in royal jelly and is also used as a quality-related marker for royal jelly ingredients.

The NZ Royal Jelly Supplement uses royal jelly material standardised to 6% 10-HDA.

Each capsule contains 340 mg of royal jelly powder, equivalent to 1,020 mg of fresh royal jelly, with approximately 20 mg of 10-HDA.

Spirulina has phycocyanin.
Royal jelly has 10-HDA.

The more closely we explore natural materials, the more we begin to discover the characteristic compounds that help define each one.

View NZ Royal Jelly Supplement →

Grape Seed — Polyphenols Stored Inside a Plant Seed

Moving into the plant world, another interesting natural material is grape seed.

Grape seeds are known to contain polyphenols including proanthocyanidins.

Their origin and chemical composition are very different from spirulina, but plant seeds also contain their own distinctive collections of natural compounds.

Blue phycocyanin in spirulina.
Polyphenols in grape seeds.

Looking at where a natural material comes from and which compounds it naturally contains opens up a much richer way of understanding foods and supplements.

Bilberry — Anthocyanins Behind the Deep Blue-Purple Colour

From the perspective of natural colour, bilberry is another especially interesting example.

Bilberries have a deep blue-purple colour, and anthocyanins are among the plant compounds associated with that pigmentation.

Bilberry supplements may also combine bilberry-derived ingredients with carotenoids such as:

• lutein
• zeaxanthin
• beta-carotene

For example, Bilberry 30,000 mg Equivalent | 60 Capsules provides per capsule:

• Bilberry fruit extract 300 mg (equivalent to 30,000 mg fresh fruit)
• Approximately 75 mg anthocyanins
• Approximately 12 mg lutein
• 2 mg zeaxanthin
• 800 μg beta-carotene

Even within the broad world of natural colour:

Spirulina blue → phycocyanin
Plant green → chlorophyll
Bilberry purple → anthocyanins
Yellow to orange → carotenoids

Different molecules create different colours.

Looking at nature as “a world of pigments” can completely change the way we see plants, microorganisms and the ingredients derived from them.

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8. Choosing Spirulina Wisely: Intake, Quality & Safety

When incorporating spirulina into everyday life, it is useful to consider not only its nutritional composition, but also the amount used, product quality, cultivation conditions and your own individual circumstances.

Use the Product Label as Your Guide for Daily Intake

Suggested spirulina intake varies according to the concentration, form and design of each product.

Human studies have also used a variety of doses, including 1 g, 2 g and several grams per day, depending on the research question.

For everyday use, the most practical starting point is the suggested daily intake stated on the individual product label.

Amounts used in clinical studies should be understood as part of those specific study conditions, while normal consumer use should follow the directions provided for the product.

Morning, Evening, Before or After Meals — Choose a Routine That Works for You

A practical approach is to follow the instructions provided with the product and choose a time that fits comfortably into your daily routine.

• check the product directions
• choose a time you can follow consistently
• take your own digestive comfort and general wellbeing into account

Connecting it with an existing routine, such as breakfast, lunch or dinner, can make regular use easier to remember.

Powder, Tablets or Capsules — Choose the Form That Fits Your Lifestyle

Spirulina products are available in several forms, including:

• powder
• tablets
• capsules
• foods and beverages containing spirulina

Powder is easy to add to smoothies, yoghurt and recipes, and it allows you to enjoy spirulina’s distinctive colour.

Tablets and capsules can make portioning straightforward and are convenient to carry.

When comparing products, consider the amount provided, quality, flavour, intended use and how easily it fits into your routine.

Look at the Cultivation Environment Too

An especially important aspect of spirulina quality is how and where it has been cultivated and manufactured.

When cyanobacteria are produced for food, cultivation conditions and raw-material control are important parts of quality management.

Appropriate control of cultivation water and raw materials helps manage potential contamination by unwanted microorganisms, other cyanobacteria or cyanobacterial toxins.

When choosing a spirulina product, useful quality indicators may include:

• clear information about the origin and cultivation environment
• a clearly identified manufacturer
• production under controlled manufacturing conditions
• testing and quality systems for microorganisms and heavy metals
• quality management relating to cyanotoxins
• a reliable distribution and retail channel

These details can reveal differences between products that are not obvious from price alone.

Raw-material control and manufacturing quality are especially important when selecting naturally derived food products.

When Trying Spirulina for the First Time, Pay Attention to How You Feel

People can respond differently to foods and supplements.

Some individuals may experience digestive discomfort, abdominal symptoms or allergic reactions when using spirulina.

When trying a product for the first time, read the suggested intake and cautions, and pay attention to how your body responds.

If you notice an adverse reaction, stop using the product. Seek medical advice if symptoms are severe or continue.

Phenylketonuria (PKU) — Check Phenylalanine Intake

Spirulina protein contains phenylalanine, one of the essential amino acids.

People with phenylketonuria (PKU) need to carefully manage phenylalanine intake.

Anyone with PKU should consult an appropriate healthcare professional or dietitian before using spirulina-containing nutritional products.

Pregnancy, Breastfeeding, Medical Treatment & Medicines

If you are pregnant or breastfeeding, receiving medical treatment, or regularly taking medication, it is sensible to discuss new supplements with a doctor or pharmacist before adding them to your routine.

Nutritional supplements form part of the broader picture of what you consume each day.

Considering your current health, medicines and other supplements together can help you make a more appropriate choice.

Three Things to Remember: Quality, Amount & Individual Needs

Spirulina has a long history of use as a food in different parts of the world.

As with many naturally derived foods, quality can vary according to raw materials, cultivation conditions, manufacturing methods and storage.

Three simple points are worth remembering:

Reliable quality.
An amount appropriate for the product.
Your own individual circumstances.

These principles are useful not only for spirulina, but for nutritional supplements and health foods in general.

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9. Frequently Asked Questions About Spirulina

Is Spirulina a Plant?

Spirulina performs photosynthesis, but biologically it belongs to the cyanobacteria.

It is a prokaryotic organism without a membrane-bound nucleus, and many of the organisms used commercially as spirulina are now classified mainly within the genus Limnospira.

Is Spirulina a Seaweed?

Spirulina is biologically different from familiar seaweeds such as kelp, wakame or nori.

Typical seaweeds are eukaryotic organisms, whereas spirulina is a prokaryotic cyanobacterium.

Both may grow in aquatic environments and use photosynthesis, but their cellular organisation is fundamentally different.

How Can Spirulina Fit Into a Balanced Diet?

Spirulina contains a variety of components, including protein, amino acids, minerals, fatty acids and natural pigments.

A varied everyday diet generally combines foods such as grains, vegetables, fruit, legumes, meat, fish, eggs and dairy products according to individual dietary needs.

Spirulina can be viewed as one distinctive food material that adds its own combination of nutritional and pigment compounds to that wider diet.

How Should Spirulina Be Viewed as a Source of Vitamin B12?

B12-related compounds can be detected in spirulina, but studies have reported that a substantial proportion may consist of B12 analogues that are not readily usable as vitamin B12 by humans.

People who need to pay particular attention to vitamin B12— including many vegans and vegetarians— should use reliable B12 sources with established bioavailability, such as appropriate fortified foods or B12 supplements.

What Research Has Looked at Weight, BMI & Body Fat?

Randomised controlled trials have evaluated body weight, BMI and body-fat percentage, and meta-analyses have combined results from multiple trials.

A 2025 analysis pooling 17 RCTs reported average between-group differences for body weight, BMI and body-fat percentage.

Body-weight management is influenced by overall food intake, nutritional balance, physical activity, muscle mass, sleep and many other factors.

Spirulina is therefore best viewed as a food material being studied within the wider context of diet and lifestyle.

What About the Term “Alkaline Food”?

Foods are sometimes described as “acid-forming” or “alkaline-forming” based on various characteristics or compounds produced during metabolism.

The pH of human blood, however, is tightly regulated within a narrow range by systems involving the lungs, kidneys and chemical buffers in the blood.

Diet can influence factors such as urinary pH.

When understanding spirulina nutritionally, it is more useful to look directly at the protein, minerals, fatty acids, carotenoids, phycocyanin and other components it actually contains.

What Research Has Been Conducted on Allergic Rhinitis?

Randomised controlled trials have investigated spirulina in people with allergic rhinitis.

A 2008 trial involving 150 participants assessed outcomes including nasal discharge, sneezing, nasal congestion and itching.

Additional comparative research has since been reported, making allergic rhinitis one of the spirulina topics that has reached human clinical investigation.

Anyone experiencing symptoms should rely on appropriate medical diagnosis and treatment, while these studies can be understood within the context of nutrition and food research.

Is Spirulina Used in Skincare?

Yes.

Spirulina-derived extracts, phycocyanin and other microalgae-related ingredients have been studied in cosmetic and dermatological research.

In commercial cosmetics, products such as the NB Rotorua Natural Mud Face Mask use spirulina as a skin-conditioning ingredient.

How Should I Choose Between Spirulina and Chlorella?

Both are green food materials, but biologically they have different characteristics.

Spirulina is a cyanobacterium and is especially distinctive for its phycocyanin.

Chlorella is a green alga and is a eukaryotic organism with a membrane-bound nucleus.

When comparing products, consider their composition, form, suggested intake, quality and how easily they fit into your routine.

Understanding the character of each material is more useful than treating them as identical “green supplements.”

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10. Summary: Understanding Spirulina Changes the Way We See “Superfoods”

The more deeply we explore spirulina, the clearer it becomes that “a nutrient-rich green food” only tells a small part of the story.

Biologically, spirulina belongs to the cyanobacteria.

Within this tiny organism, we find a high proportion of protein alongside essential amino acids, minerals, fatty acids, carotenoids, chlorophyll and phycocyanin.

Many different nutritional and pigment compounds coexist within one remarkably small organism.

Phycocyanin is especially distinctive: not only does it contribute to spirulina’s vivid blue colour, it also participates in the transfer of light energy during photosynthesis.

Human research has expanded into topics including allergic rhinitis, blood lipids, blood pressure, body composition, gut-related outcomes and exercise.

The best way to interpret those studies is to look at who participated, how much was used, how long the study lasted and what was actually measured.

From Food to Beauty

Spirulina has also moved beyond the food field into cosmetic and skincare applications.

The NB Rotorua Natural Mud Face Mask 200g combines Rotorua thermal mud, bentonite and kaolin with royal jelly, spirulina and vitamin E.

A material first encountered as a food can be viewed again from the completely different perspective of skincare.

That shift in use reveals another side of the same natural material.

View NB Rotorua Natural Mud Face Mask 200g →

Looking More Closely at Nature Opens Up an Even Wider World

From spirulina, we can expand our view towards other natural materials such as royal jelly, grape seed and bilberry.

Spirulina has phycocyanin.
Royal jelly has 10-HDA.
Grape seed contains polyphenols such as proanthocyanidins.
Bilberry contains anthocyanins.

Nature produces different combinations of molecules in different organisms and plants.

Studying spirulina more deeply encourages us to ask:

“What kind of organism is this?”
“What compounds does it contain?”
“What exactly are researchers measuring?”

Seen this way, spirulina extends far beyond the label of a health food.

It is also a fascinating research material connecting biology, nutrition, food science, cosmetics and biotechnology.

From the Lake to the Table — and Then to Space

Centuries ago, spirulina-like biomass was collected from lakes and used as food.

Today, research spans food science, nutrition, cosmetics and biotechnology.

In 2026, the Japanese Experiment Module “Kibo” on the International Space Station hosted an experiment investigating spirulina cultivation with the aim of efficient protein production and carbon-dioxide processing.

From the lake to the table.
From the table to the laboratory.
And from the laboratory to space.

The world surrounding this tiny cyanobacterium is far larger than it first appears.

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References & Sources

1. Sinetova MA, Kupriyanova EV, Los DA. Spirulina/Arthrospira/Limnospira—Three Names of the Single Organism. Foods. 2024.
2. Habib MAB, Parvin M, Huntington TC, Hasan MR. A Review on Culture, Production and Use of Spirulina as Food for Humans and Feeds for Domestic Animals and Fish. FAO Fisheries and Aquaculture Circular No.1034. 2008.
3. Spínola MP, Mendes AR, Prates JA. Chemical Composition, Bioactivities, and Applications of Spirulina (Limnospira platensis) in Food, Feed, and Medicine. 2024.
4. Watanabe F, Takenaka S, Kittaka-Katsura H, et al. Characterization and bioavailability of vitamin B12-compounds from edible algae. J Nutr Sci Vitaminol (Tokyo). 2002;48(5):325-331.
5. Cingi C, Conk-Dalay M, Cakli H, Bal C. The effects of spirulina on allergic rhinitis. Eur Arch Otorhinolaryngol. 2008.
6. Nourollahian M, et al. Clinical comparison of the efficacy of Spirulina platensis and cetirizine for treatment of allergic rhinitis. 2020.
7. The effect of Spirulina supplementation on lipid profile: GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials. 2023.
8. Shiri H, et al. The Effect of Spirulina Supplementation on Blood Pressure in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Clinical Trials. Phytother Res. 2025.
9. Lak M, et al. Effects of spirulina supplementation on body composition in adults: a GRADE-assessed and dose-response meta-analysis of RCTs. Nutr Metab. 2025.
10. Effects of Spirulina supplementation on intestinal permeability, antioxidant and inflammatory markers, quality of life and disease severity in patients with constipation-predominant irritable bowel syndrome: a randomized double-blind placebo-controlled trial. 2025.
11. Potential application of Spirulina in dermatology. 2022.
12. Comprehensive Review of the Latest Investigations of the Health-Enhancing Effects of Selected Properties of Arthrospira and Spirulina Microalgae on Skin. 2024.
13. United States Pharmacopeia. Safety evaluation of Spirulina. 2011.
14. U.S. Food and Drug Administration. Blue-Green Algae Products and Microcystins.
15. JAXA Human Spaceflight Technology Directorate. Space Surface Spirulina: Cultivation of Spirulina using the Immobilized Biofilm Photo-Bioreactor for Efficient Protein Production and Air Revitalization. 2025–2026.
16. JAXA. Space Surface Spirulina: Cultivation Demonstration Using an Immobilized Biofilm System for Efficient Protein Production and CO2 Processing aboard the International Space Station “Kibo” module. 2026.
17. NASA. Nutrition Research Arrives Aboard Space Station. Space Surface Spirulina / JAXA experiment. 2026.