These Spirulina Benefits Will Make a Splash

Here, everything you need to know about this so-called "superfood," including how to add the blue-green ingredient to your diet.

green spirulina powder and spirulina supplements
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Another day, another green powder…or so it seems. Spirulina powder — a blue-green algae that's known for adding a vibrant color to any dish — is one you might see on ingredient lists at your favorite smoothie joint or across your social media feeds. But is the nutrition hype legit or is spirulina just a pretty face? Read on to learn about the health benefits of spirulina, potential risks, and ways to eat the aquatic ingredient that tastes as good as it looks.

What Is Spirulina?

Spirulina is a type of cyanobacteria, aka blue-green algae, that grows in both freshwater and saltwater in tropical regions such as Central Africa, Asia, and Central America, according to a 2020 scientific review. While it can be eaten live or raw (think: taken out of the water, strained, and then eaten), spirulina is most commonly consumed as a powder — the dried, processed form of the algae you've likely seen before.

Fun fact: The term "spirulina" actually refers to several cyanobacteria varieties, rather than just one organism or one ingredient. For the purpose of this article, "spirulina" will refer to the species in general. (Similarly, farro actually refers to three types of wheat, but, like spirulina, is often considered a singular food item. Hey, the more you know!)

Spirulina Nutrition Facts

The World Health Organization has actually dubbed spirulina a "superfood," according to a 2019 scientific review. Loaded with nutrients such as B vitamins, potassium, and calcium, the aquatic algae also contains phycocyanin, an antioxidant and blue-green pigment that's responsible for spirulina's color.

In addition to being known for its wide range of micronutrients (it boasts vitamin E, iron, and magnesium too), spirulina stands out for its "high protein content," according to the aforementioned review. Now, spirulina is no chicken or Greek yogurt. But it packs an impressive amount of protein into a small package: 4 grams per tablespoon to be exact, according to the United States Department of Agriculture (USDA).

Here's the complete nutritional profile of 1 tablespoon (~7 grams) of dried spirulina powder, according to the USDA:

  • 20 calories
  • 4 grams protein
  • 0.5 grams fat
  • 2 grams carbohydrate
  • <1 gram fiber
  • <1 gram sugar

Health Benefits of Spirulina

Okay, so spirulina is packed with nutrients, but what does that mean for your diet? Read on to learn about the health benefits of spirulina, according to dietitians and scientific research.

Fights Oxidative Stress

Responsible for spirulina's blue-green color, phycocyanin is also a potent antioxidant, according to Megan Byrd, R.D., registered dietitian and founder of the Oregon Dietitian. Meaning, it combats oxidative stress by neutralizing harmful free radical molecules before they can potentially damage cells and organs and cause said oxidative stress. This is key because high levels of oxidative stress can increase the risk of developing chronic diseases such as cancer and type 2 diabetes.

But phycocyanin isn't playing alone. Spirulina also contains some beta-carotene, an antioxidant that gives fruits and veggies (hi, carrots and cantaloupe) an orange color, notes Byrd. Together, phycocyanin and beta-carotene inhibit the activity of free radicals and stimulate antioxidant molecules in cells, making spirulina a stellar antioxidant food, according to a 2016 scientific review.

Improves Allergies

ICYDK, allergic rhinitis (aka hay fever or, quite simply, allergies) happens when you're allergic to substances such as pollen, mold, or dust mites, according to the American College of Allergy, Asthma & Immunology. It's essentially an overreaction of the immune system, which, upon interacting with these allergens, releases histamine, an inflammatory chemical that causes symptoms such as sneezing and itchy eyes. And while antihistamine medication such as Zyrtec or Claritin can ease these symptoms, spirulina might be able to help too. In a 2020 study, people with allergic rhinitis took either 2 grams (about 1/4 tablespoon) of spirulina or 10 milligrams of cetirizine (the active ingredient in Zyrtec). And the spirulina group experienced more relief — reduced nasal drainage, sneezing, congestion, and itching — than the cetirizine group.

May Support Heart Health

High blood pressure and high blood cholesterol levels are major risk factors for heart disease, according to the Centers for Disease Control and Prevention. The phycocyanin in spirulina, however, may protect your heart by improving these factors. "According to animal studies, phycocyanin may help lower blood pressure by enhancing the production of nitric oxide," explains Basheerah Enahora, M.S., M.B.A., R.D.N., L.D.N., founder of BE Nutrition. Nitric oxide plays a vital role in vasodilation (the relaxation of blood vessels), which improves blood circulation and, as a result, reduces blood pressure, she explains.

The algae might also help increase HDL or "good" cholesterol and reduce LDL or "bad" cholesterol, but more research is necessary, adds Byrd.

Could Improve Anemia

Your body uses iron to make red blood cells, which are in charge of carrying oxygen to all your tissues. But you can develop iron deficiency anemia — a condition marked by low red blood cells due to low iron intake. The condition can make you super tired, but eating iron-rich foods can help reverse your symptoms. This is where spirulina might come in. Spirulina (a pretty good source of iron) is conventionally used to treat anemia, according to a 2017 scientific review. While there is limited evidence to support this spirulina benefit, one theory behind it has to do with tiny compounds found in spirulina called polyphosphate bodies, explains Enahora. "Polyphosphate bodies may aid the absorption of iron [in] the intestines, which can improve your iron levels," she explains.

Might Support Immunity

There's some evidence that spirulina may boost the immune system by enhancing the activity of lymphocytes, aka immune cells that "eat" harmful germs. This effect was observed in a 2020 animal study, in which spirulina increased lymphocyte levels in mice. A 2016 human study also found that spirulina increases interleukin-2, a molecule that supports a healthy immune response. However, there's limited human research on spirulina's effects on the immune system, so more studies involving people are needed to draw any solid conclusions.

Potential Risks of Spirulina

Spirulina is "generally recognized as safe" by the Food and Drug Administration, according to the aforementioned 2017 scientific review. But as with all new-to-you supplements or foods, it's best to chat with your doctor before giving it a try to ensure spirulina won't interact with other supplements and/or prescription drugs already in your regimen. This is especially important if you're taking immunosuppressants, which may negatively interact with spirulina, according to Icahn School of Medicine at Mount Sinai.

In some folks, spirulina can cause side effects such as digestive issues, muscle pain, sweating, facial flushing, and headaches. And while spirulina might have the power to improve allergy symptoms, it can potentially cause allergic reactions too. In a 2020 case report, two people developed hives, itching, and difficulty breathing after eating spirulina. If you have a history of allergies, speak to your doc before adding the algae to your routine. The same goes if you're pregnant or breastfeeding, as there's minimal evidence on how spirulina affects either.

What's more, spirulina poses the risk of being contaminated with heavy metals such as nickel, aluminum, or lead, according to a 2018 article. These metals can cause health issues such as nervous system damage and kidney problems, according to a study in the Science of the Total Environment. Basically, spirulina can absorb heavy metals from the environment so effectively that it's been purposely used to remove metals from wastewater in industrial scenarios. Play it safe by buying spirulina from a reputable brand.

How to Buy and Eat Spirulina

You can find spirulina at the grocery store or health market in various forms. As a supplement, it's available as a powder, liquid extract, gummies, capsules, and tablets. You can also find it as an ingredient in protein and green powder blends — such as Nested Naturals Super Greens Powder (Buy It, $29, — which are designed to be dissolved in water or juice, adds Byrd. Some stores sell products infused with spirulina powder, such as beverages, pasta, cookies, and snack bars including Shanti Balance Crunchy Almond Spirulina Bars (Buy It, $25 for 12,

Looking for the healthiest option? Reach for spirulina powder — such as BN Organic Spirulina Powder (Buy It, $11, — which typically contains just one ingredient: spirulina. This means it offers a purer, more potent nutrient profile compared to other supplements, says Kelsey Lorencz, R.D., a registered dietitian and founder of Graciously Nourished. But heads up: Spirulina powder has a fishy pond-like taste and smell that some people might notice. If you're not a fan, "a gummy, pill, or a mixed powder [blend] might be a better option, but you'll want to watch out for added sugars, flavors, and dyes," notes Lorencz. You can also try combining straight spirulina powder with citrus to reduce the intense fishy profile, recommends Enahora.

Also, when choosing any kind of spirulina supplement, be mindful of its source. "Look for spirulina harvested from natural lakes or grown in controlled commercial ponds," says Enahora, as this will limit the risk of heavy metal contamination mentioned above. While you're at it, make sure the brand has third-party certifications, she adds. Third-party certification means that an independent organization has tested the product for safety and quality. This is especially important since "spirulina production, dehydration, and storage can significantly reduce its antioxidant content," notes Enahora. Buying a third-party certified product, though, will ensure you get the most bang for your buck. Usually, you can find these certs on a product's packaging.

Spirulina is also available live (i.e., not dried) from specialty manufacturers, such as Raw Living Spirulina Fresh Raw Living Spirulina (Buy It, $89, This version is typically used in smoothies and drinks. Brands that make raw, live spirulina claim that it's more nutritious because it's not processed as is the case with a powder, but "it's tough to find research comparing the two," notes Lorencz. Plus, live spirulina is more expensive and requires refrigeration, as it's less shelf-stable than powder. TL;DR — spirulina powder is the more practical and budget-friendly option.

If you're ready to give spirulina a spin, here are a few tasty ways to use it at home:

In a smoothie. One of the easiest ways to enjoy spirulina is to add 1 to 2 teaspoons to your morning smoothie. Pro tip: Orange will tone down the fishy smell, but you can also try blending it with other citrus fruits, such as lemon or grapefruit.

In juice. Try stirring spirulina powder into juice, recommends Byrd. Again, 1 to 2 teaspoons will do the trick, and citrus juices (i.e. orange juice) are your best choice.

In energy balls. Give your energy balls a nutritional boost with spirulina, suggests Enahora. Add one teaspoon to your go-to energy ball recipe or try these chocolate spirulina superfood energy bites by the food blog Grateful Grazer. If you're concerned about the fishy taste, try adding lemon zest to the recipe.

In banana ice cream. The next time you make banana ice cream, add 1/2 to 1 teaspoon of spirulina powder. Better yet, add a few wedges of oranges. The spirulina will add nutrients and color, says Enahora, while the orange will tame its fishy notes.

In soup. Spirulina also works well in green soups, where it deepens the dish's color. Try it in this coconut supergreens and spirulina soup from the Hungry Herbivores.

In overnight oats. Thanks to spirulina, you can switch up your breakfast game and make blue-green oats. Need inspo? Check out this blueberry spirulina overnight oats recipe by Delightful Vegans.

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