3/4 Spirulina 101: The Uses

Klara Zietlow
16 min readNov 28, 2021


This is article 3/4 in my spirulina 101 series on the different properties spirulina has and the ways it can be used. In case you missed it, here’s article one, the introduction, and article two, different methods of growing and harvesting the microalgae. If you want to learn about what’s preventing mass adoption, check out article four.

A little toolbox in disguise

Of course, spirulina is super healthy and its use as food has been the main focus of the series, but spirulina is so amazing it can actually be used in a whole array of sectors.

But first, food:

Nutritional Properties

Way back in 1974, the United Nations declared spirulina a superfood. Having a 55–70% complete protein content places it above almost all other protein sources including meat, eggs, and milk.

Spirulina also contains 180% more calcium than whole milk, 3100% more beta carotene than carrots, 5100% more iron than spinach, and more antioxidant and anti-inflammatory activity in 3 g of spirulina than in five servings of fruits and vegetables!

You mean one green thing can replace all of these green things?

Additionally, its lack of cellulose in its cell wall makes it easily digestible, suitable for those with poor intestinal absorption and gastriatric people (those with an inflamed stomach lining).

The list of other benefits spirulina offers goes on seemingly forever. There’s research saying it can do everything from preventing cancer and HIV to reducing cholesterol and building up blood cells.

I won’t rattle every claim off, but I’ll go into the parts I think are most impactful and well backed. If you want a more comprehensive list, Examine has what you need (and probably more ;)).

How to Not Get Sick

Spirulina’s effect on our immune systems is one of the best backed areas of research.

It helps modulate the production of cytokines (small proteins important in cell signaling) by our peripheral blood mononuclear cells. This isn’t surprising given its rich content of flavonoids (fights off free radicals) and sulfolipids (important in photosynthesis).

Pretty cytokines that spirulina helps us make more of I Physiopedia

Spirulina products also contain bioactive proteins with the ability to stimulate the intestinal immune system to enhance responsiveness to vaccines and improve allergic rhinitis.

Sneezing in Spring

Spirulina is also very effective in controlling allergies and relieves symptoms such as nasal discharge, sneezing, nasal congestion, and itching. It’s also been shown to restore lost smell.

Basically, all the nose things I Unsplash

In a study the decrease in nasal congestion when spirulina was taken was remarkably strong compared to a placebo and other pharmaceutical drug tested.

Quantity Matter When It Comes to Candida

According to researchers, “Candida species belong to the normal microbiota of an individual’s mucosal oral cavity, gastrointestinal tract and vagina.” This means healthy levels of it are fine and actually help prevent disease and sickness!

But when the microfloral balance is off, there’s a direct connection to a bunch of issues like leaky gut syndrome, improper digestion, and even acne. Furthermore, invasive candidiasis is the leading cause of mycosis-related death in the U.S.

Unlike cytokines, this pretty medical image is something we definitely don’t want more of I Tips for Women

Our shift towards a diet processed foods coupled with antimicrobial resistance and ineffectual antifungal drugs has led to a rise in yeast infections since the ‘80s.

Several animal studies have shown that spirulina is effective in eliminating candida. It also promotes the growth of healthy bacterial flora in the intestines to outcompete candida.

And, as we learned in the last section, the immune-strengthening properties of spirulina can help the body eliminate any remaining candida cells.

Stopping Anemia in 8 Weeks

Anemia is the condition when the body doesn’t have enough healthy red blood cells. Globally, almost 50% of preschool aged children and over 40% of pregnant women are anemic. In India, the numbers are higher at 70% for children under five and 50% for women in general.

Severely anemic young women in India I Times of India

Anemia can cause premature births, low birth weight, postpartum hemorrhages, and other maternal complications in pregnant mothers. Among young children, stunting and growth-retardation is common.

In addition, anemia is the second highest contributor to maternal mortality in Asia.

3 Causes

Anemia can be caused in three ways: blood cell loss from bleeding, blood cell destruction, and decreased blood cell production.

Blood cell loss from bleeding is typically found in women and often related to heavy or prolonged menstrual cycles. It can also be due to hookworm infestation, which is common in poorer countries.

Cell destruction is usually only seen in patients with sickle cell anemia or some sort of infection.

The last of these, decreased blood cell production, is often due to a nutritional deficit. This could be of B12 or B9, but 50% of anemia cases are a result of iron deficiency.

Iron Deficiency Causes 50% of Anemia Cases

Iron plays a vital role in our bodies by making hemoglobin. This is a protein in our blood cells that transports oxygen from our lungs to the rest of our body.

For people who are deficient, iron supplements can be taken but they’re not well absorbed. The typical iron supplement has only a 10% absorbance rate!

In comparison, iron from spirulina has an absorbance rate somewhere between 70 and 95%. Spirulina also contains Vitamin C, a micronutrient that helps make iron more bioavailable.

That’s why it’s often advised to take iron supplements with orange juice I Gestational Diabetes UK

There’ve been many studies on the effects of taking spirulina on anemia published in reputable, peer reviewed journals (including Nature!).

The paper published in Nature looked at how spirulina affected anemia and immune function in senior citizens. There were some interesting findings about which age groups benefit the most and for how long they need to supplement, but the most important result is that anemia was reduced and immune function increased all while no other significant effects on the body were experienced.

A study done in 2017 on pregnant women in their last trimester showed spirulina supplementation was more effective than iron and folic acid supplementation in treating and preventing anemia. When supplementation was continued until the 42nd postnatal day, the weight and hemoglobin levels of babies significantly improved as well.

Another study done on pregnant women in their second trimester showed spirulina increased mean hemoglobin levels from 10.16 g/dl to 13.6 g/dl, a healthy number after eight weeks. The other group of women in their study, taking iron supplements, showed no significant improvement. Although the study had some flaws including a small sample size and various unplanned disruptions, it confirms what other experiments have concluded.

Laid out side by side, it’s clear to see spirulina works much better than iron supplements I Paper

I was only able to find one study that found spirulina consumption didn’t increase hemoglobin levels in anemic women. As concluded by the authors of the paper, this could be explained by their short (3 month) study period, minimal amount of spirulina consumed, or form in which it was consumed.

The study gave participants 3g of spirulina daily in the form of chikki bars, a snack popular in India.

What the bars may have looked like I Fifty5 Plus

Chikki bars contain oxalates and phytates, compounds that can inhibit iron absorption. As a result, the 3g of spirulina in the bar may not have been enough to overcome the effect.

Additionally, due to cultural issues, stool was not collected to determine whether women participating had hookworm infections. Anemia is strongly associated with moderate to heavy hookworm infection because of blood loss and may therefore explain the results inconsistent with other studies.

B12 Controversy

Vitamin B12 deficiency can also lead to anemia because it helps produce red blood cells and decreases weakness and fatigue.

In the past, spirulina was marketed as a great source of this vitamin B12 which is hard to get on a vegan diet. In fact, just 20g of spirulina has 10.7 mcg of it (184.6% of the recommended daily value).

But, it’s actually inactive pseudovitamin B12. That’s right, it’s an imposter 😲 This means it can’t be used like real B12 and is biologically inactive in humans.

The European Journal of Biochemistry found that pseudovitamin B12 is 500 times worse at binding to intrinsic factor, a protein necessary in the absorption of Vitamin B12, than true B12.

Additionally, The American Journal of Clinical Nutrition published a study in 1991 where toddlers with B12 deficient anemia were given spirulina over 4–6 months. Their condition didn’t improve, in fact by the end of the study their anemia had gotten worse!

That’s not to say spirulina shouldn’t be eaten, it just shouldn’t be taken as a source of Vitamin B12. If vegans are deficient in that area, they’re much better off taking a supplement.

How to Save Millions of Arsenic Poisoned People

It’s 1993 and you’re in Bangladesh. Most of your drinking water comes from shallow tube wells. People all around you are sick, falling ill to all sorts of disorders that no one can trace.

Turns out half of Bangladesh’s population, 57 million people, are consuming arsenic from contaminated tube wells.

An example of a tube well in Bangladesh that could be contaminated I Vox Dev

Over 30,000 people have signs and symptoms of chronic poisoning. This starts with hyperpigmentation, then leads to keratosis on the palms and soles with fissures, cracks, and warty lesions. Finally, horrible conditions like cardiovascular disease, developmental abnormalities, neurologic and neurobehavioral disorders, diabetes, hearing loss, hematological disorders, and various types of cancer can all follow…just because of the arsenic in their water.

Today, contamination isn’t as horrible, but around the world millions of people are still dying from toxic arsenic concentrations in their drinking water.

This is all that was needed to cure their horrible symptoms I Retail Pharma

There isn’t an effective long-term treatment. In a study by Misbahuddin et al., people with chronic arsenic poisoning were given a caplet with 250 mg spirulina extract & 2 mg zinc to take twice daily after meals for 16 weeks. Zinc supplementation reduces arsenic in rat tissue.

The amount of arsenic measured in the hair of patients given the pill was almost halved, whereas those given the placebo saw no noticeable differences.

When There’s No Food, There’s Spirulina

In 2016, a study hoping to decrease malnutrition in children living on the Gaza Strip experimented with spirulina supplements. After only three months of study, the previously malnourished children had increased their weight and height. Many who had been anemic improved as well.

Chronic conflict on the Gaza Strip has lead it to become almost unlivable I UNRWA

Spirulina is more effective in combating malnutrition than pure vitamins and minerals due to the abundance of amino acids present in it which aid in muscle mass reconstitution and anabolism (molecule construction).

Spirulina capsules could be a great thing for aid organizations to supply to poor and malnourished communities.

Spirulina tablets and capsules last a long time, perfect for uncertain environments I Dermstore

Or, you can go the route of these nuns in Central African Republic who’ve single-handedly built their own concrete tanks to grow spirulina to treat malnourished babies.

All the babies need is a spoonful a day I PBS News Hour

According to Sister Margherita, “none of our babies die anymore, we have a huge success with this.”

Fresh vs. Dry, a Trade Off

Although all of the studies above used a dry form of spirulina, fresh and frozen spirulina are 5x more powerful against anemia than powders which contain only 20% of the vitamins and minerals that fresh spirulina does.

Fresh and frozen spirulina have impracticalities, especially in war zones and places of famine where they could be most needed. For example, fresh spirulina only lasts about 4 weeks. Additionally, both fresh and frozen forms need to be kept cold.

Frozen cubes from We Are The New Farmers and fresh spirulina from Raw Living Spirulina

Nevertheless, dry spirulina still has amazing effects on health as shown by the studies above so is certainly better than nothing!

Way Beyond Food

Although the focus of the series has mostly been on spirulina production for human food, there plenty of other reason to grow it.

Pigments but Safe + Healthy

Pigments are substances that add color to products. This section will focus on food coloring but I’ve seen spirulina used to color soap, beauty products and even paint.

The rise and fall of synthetics

What even is a blue raspberry?!? I Touchstone Essentials

Synthetic dyes, which mainly are derived from coal tar, are banned in many countries. The first synthetic dye was discovered in the 19th century and by 1900 many foods, drugs, and cosmetics in the US were artificially colored.

The problem was, this was often used to mask inferior or bad products. In 1950, many children became sick after ingesting orange Halloween candy containing 1–2% FD&C Orange №1, an additive approved for use in food. This caused the FDA to reexamine many artificial dyes which were found to cause adverse effects.

I guess the myth about tainted Halloween candy wasn’t so wrong after all? I Delish

And although lots of foods are still artificially colored today, this incident was the start of a push for more natural food colorings, derived from plant or mineral sources, which are generally safer.

Sooo, enter spirulina! 🥳


The first color spirulina offers is pretty obvious: green! Whether you like it or not, the chlorophyll in spirulina will turn anything and everything you add to it green.

Everything in here automatically not only looks healthier, but is healthier with spirulina!

Although sometimes making it hard to market products, especially to children ;), the color of spirulina can come in handy when trying to incorporate it into something like mint chip ice cream.


Something that has recently been all over social media is azure “mermaid” food colored with blue spirulina.

Just some of the many, many, many things you can color with blue spirulina

Although this blue color is very different from spirulina’s typical green, they’re actually the same thing. Blue spirulina is another name for phycocyanin–the blue-colored pigment in the phycobilin family present inside of spirulina.

Extraction of the pigment is on the molecular level and only available to those with established farms. First, blue-green algae must be crushed to break their cell walls after which chemical compounds are added to separate the phycocyanin pigments from the cell. Then it must be verified, dried, and sent to be packaged.

Phycocyanin is rich in vitamins, minerals, protein, antioxidants, and carotenoids, just like pure spirulina. But if you think about taking a Vitamin C pill versus an entire orange, the pigment extracted isn’t as nutritious as whole spirulina.

Phycocyanin is only found in spirulina and a few other species of blue-green algae. It has a more neutral taste than green spirulina but also costs significantly more. Anything for the gram, I guess…

Instant 1 million coolness points I Unicorn Superfoods

Spira is one company selling phycocyanin commercially. In addition to their green “Umi” pigment, they also offer a shocking blue “Electric Sky” to mix into beverages and confectionaries.

Spira’s Electric Sky blue pigment next to Umi, their plain green pigment


If a yellow pigment is desired over a blue one, spirulina also contains high amounts of lutein, although this is used much less commonly.

It’s much harder to extract this from a blue-green algae than a blue color I Pine Pollen Tablet

It’s been shown that lutein content significantly increases if spirulina is grown in seawater without affecting growth and productivity.

Animals + Spirulina = 😻📈

Today, half of all spirulina production is used in livestock and fish feeds. One benefit of feeding it to animals instead of humans is that although unpleasant, desalinated wastewater and animal faecal matter can be added to enrich the growth medium. And yes, I know it’s kind of disgusting, but studies show it’s perfectly safe to be used.

Also, you don’t need a whole marketing team to get a cow to eat it. As long as the performance (and a reasonable price) is there, a farmer will buy it.

See! They only look a tiny bit suspicious :) I Algenerg

Spirulina can substitute up to 50% of the protein in conventional feeds but is unlikely to happen because of cheaper sources like soy and fishmeal. Luckily, it doesn’t need to be at such a high concentration to have effects.

Growth rates of fish and poultry improved at even 0.1% spirulina so effects may be even more than nutritional. It might mimic or stimulate growth hormone production. Besides growth rate, color enhancement and general tissue quality also improved.

🐟 When fed to fish, the presence of carotenoids enhanced their color. This isn’t a priority unless for higher value products such as shrimp, salmon, or ornamental/exotic fish. Even so, cheaper sources of carotenoids such as paprika and Phaffia, a type of yeast, can achieve similar effects, albeit to a lower extent.

The many shades of salmon — darker colors sell for more I The Globe and Mail

🐔 When given to hens, the cholesterol content of eggs was lowered, antioxidants and omega 3s increased, and yolk color intensified. For meat chickens, the color of their meat was also enhanced, likely due to the accumulation of carotenoids present in the ingested cyanobacteria.

🐐 Putting spirulina in ruminants’ water can be a method of encouraging water consumption due to the added sodium from spirulina.

🐄 Cows increased milk production by 21% when fed spirulina and had a significant decrease in milk somatic cell count. Milk somatic cell count is a way of determining milk quality. The majority of somatic cells found in milk are leukocytes (white blood cells), which become present in large numbers as an immune response to pathogens. Basically, the fewer present, the healthier an animal is likely to be and the safer it is to drink that milk.

The most cost effective reason for including spirulina in animal feed is its immune enhancing, antiviral, anticancer, and antibacterial properties. During the first few weeks of life, young animals have a deficient immune system. For example, many marine fish larvae die from infections by pathogens every year and in an effort to keep infections at bay are fed antibiotics. This is both ineffective and can cause undesirable safety consequences for the customer.

Vitamins are sometimes fed to animals to boost their immune system, but since spirulina contains carbs, proteins, and lipids in addition to micronutrients, it’s more cost effective.

Biopolymers for Greener Materials ;)

Not only will spirulina soon be in the food we eat, it might also help package it! Biopolymers are analogous to polymers of petrochemical origin and used to create bioplastics. PHA is a biopolymer naturally produced by prokaryotic microorganisms as a storage material, typically when under stress. PHB, a type of PHA, functions in carbon energy storage.

Bioplastic made with agar and spirulina I Recipe here

By adjusting the nutrient medium, PHA and PHB can be increased in spirulina. The quality of PHB polyesters produced by cyanobacteria is comparable to that of polyolefins (synthetic polymers) but more expensive.

Even Your Car Will Love Spirulina

Because of how quickly microalgae grow, they’re a great crop to create biofuel out of. Microalgae are rich in lipids like the oil crops commonly used for biofuels, but they grow much quicker.

Algae meant for biofuel I Digital Trends

Despite this, as with most uses for microalgae, it’s much more expensive than the conventional method. Biodiesel from microalgae containing 30% lipids including conversion costs, taxes, and marketing is ~$2.8 per liter, which is 2.4x more expensive than diesel from oil ($1.1).

Ethanol is the most widely used biofuel globally. 10% of ethanol production comes synthetically from petroleum and the other 90% is derived from alcoholic fermentation. Bioethanol can be made from any natural substance that has carbs which can be hydrolyzed and converted into ethanol by yeast during fermentation.

The concentration of lipids and carbs in spirulina are 10 and 15%. As a result, it hasn’t traditionally been used for biodiesel or bioethanol. But, because it has a high production capacity and the carb levels can be brought up to 50% by changing their nutrient medium, it could be a promising source for bioethanol.

Smear It On Your Skin

There are dozens of claimed benefits beauty brands feel entitled to market you on as soon as they stick the slightest bit of spirulina extract in their product. Although many promises can’t be backed up, spirulina does have remarkable effects on skin when applied topically.

Moisturization Station

In one 2015 study, gel-cream moisturizer with and without dry spirulina extract was given to women of varying ages.

There are a few companies, such as Earth Harbor, that make spirulina moisturizer

The fatty acids in spirulina improved the oily skin appearance of subjects and reduced overall water loss and sebum content. Furthermore, polysaccharides in the algae stimulated the cell division process in the outer skin layer, renewing the stratum corneum.

Other vitamins, minerals, and proteins in the extract may have further improved skin hydration and microrelief.

Spirulina Sun Protection

When put into sunscreen, the flavonoids in spirulina help to protect against UV radiation. The perfect amount is 7% spirulina, which is a great balance between high SPF (30) and stability.

Kōkua Sun Care makes a sunscreen with spirulina, one of the very few that do!

Spirulina supplemented sunscreen significantly improves both skin elasticity and health of the dermis (second layer of skin) after 84 days of the treatment.

Why Use Zit Cream When You Can Use Spirulina?

While acne may not be the most important health issue facing the world, I know as a teen with frequent acne, it can lead to insecurity and body shame.

Acne forms when there’s too much sebum in your pores which then clog and inflame causing pimples.

As a natural antimicrobial, spirulina kills off candida (yeast), which often contributes to breakouts. There’s also a plethora of bacteria that can contribute to acne flares. These bacteria are scarily becoming resistant towards synthetic drugs like Tetracycline.

In 2018, Nihal et al. developed a topical treatment for acne with phycocyanin (blue spirulina). The goal was to reduce the proliferation of C. acnes, a bacteria tied to acne. Three different masks were formulated: one with spirulina, one with clindamycin (a common synthetic antimicrobial drug with proven effects), and one with no active ingredients.

As expected, the mask with no active ingredients did nothing. The spirulina and clindamycin masks were both very effective and had similar levels of C. acnes inhibition! Go spirulina!!

And Many More

These are just a few applications of spirulina. There are new applications being explored everyday! Like just last week I saw an article about using algae to purify air in an indoor playground…who could’ve imagined!

Who could’ve imagined I Dezeen

Although by now you must think spirulina can solve every problem in the world, there are still many reasons why it won’t (yet). In the last article of the series, learn what’s stopping spirulina from becoming mainstream.

If you didn’t read article one, the Introduction, or article two, methods of growing and harvesting spirulina, be sure to check them out!

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Klara Zietlow

Passionate about the future of food and the environment. Likes animals too :)