6 Best Spirulina Supplements (2024) Reviewed and Compared

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Green powders are everywhere nowadays. And it’s easy to see why. They’re like a nutrient “cheat sheet” you can throw in your morning smoothie or post-workout shake.

One of the most popular ingredients in greens powers is Spirulina. It has a following as a sustainable and eco-friendly vegan protein source.

Spirulina is a blue-green microalga from single-celled Arthrospira platensis cyanobacteria. Don’t worry; it’s a non-infectious bacterium that grows in freshwater and saltwater ecosystems. It also happens to be one of the oldest life forms on the planet.

It’s grabbed the attention of researchers for its antioxidant, anti-inflammatory, blood sugar, cardiovascular, and immune health benefits.

Spirulina Should Be Third-Party Tested

I’m going to level with you; supplementing with spirulina is risky. If it’s not grown and produced under strict conditions, there’s a risk of contamination from heavy metals, pollution, toxins, and other bacteria.

Purchasing spirulina from a reputable brand is essential.

What are the Best Spirulina Supplements in 2024?

With that said, here is our list of the best spirulina supplements on the market. They are made according to current Good Manufacturing Practice (cGMP) standards and thoroughly assessed for safety.

*Note: We have affiliate links throughout this article, which means we receive a commission if you buy from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.

1) Nutrex Pure Hawaiian Spirulina

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Nutrex Hawaii delivers the purest Hawaiian Spirulina in 500 or 1000 mg tablets.

Their patented Spirulina® Pacifica® is grown in a biosecure zone on the Kona Coast of Hawaii. This environment ensures it’s free from GMOs, harmful bacteria, heavy metals, toxins, and glyphosate (pesticide) residues.

Once harvested, the spirulina is dried with Ocean Chill Drying technology in a cGMP facility.

Each 3-gram serving provides 225 mg of active phycocyanin. Plus, it’s free from gluten, soy, and lactose; and certified vegan, kosher, and halal.

2) Pure Bulk Spirulina (Best Bulk Option)

Spirulina bulk

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Pure Bulk offers third-party accredited supplements at great prices.

Their spirulina is made from Arthrospira platensis biomass and free from soy, dairy, yeast, gluten, corn, additives, fillers, and anti-caking agents. Basically, it’s the purest of the pure.

It’s available in powder and capsules. The powder is the most cost-effective – a 500-gram bag is just $19. One easy-to-mix tablespoon delivers 8.5 grams of spirulina.

However, the taste isn’t everyone’s cup of tea. It has an intense flavor that’s difficult to mask – it’s a bit like seaweed. If you don’t mind the taste, add it to water, smoothies, juice, soups, and sauces.

The capsules are also a quality bulk choice if you’re not interested in powder.

However, we suggest skipping this brand if you’re trying spirulina for the first time.

3) Double Wood Blue Spirulina Powder

Blue Spirulina Powder

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Each 1-gram serving of Double Wood Blue Spirulina provides 350 mg of phycocyanin. This is a highly concentrated pigment, which explains the powder’s vibrant blue color.

Interestingly, blue spirulina is considered more palatable than regular blue-green spirulina. As a bonus, you can use it to make visually appealing blue smoothie bowls, milkshakes, and cakes. Your Instagram feed will be poppin’ (as the kids say).

The powder is thoroughly evaluated for purity, and the results are available on their website.

A tub will last one month if you take 1 gram per day. However, this powder is not a great option if you want a higher daily dose.

4) NOW Organic Spirulina Tablets

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NOW Foods Spirulina is made from non-GMO, certified-organic spirulina.

The tablets are free from corn, gluten, and eggs and certified vegan, halal, and kosher. You can choose between 500 mg and 1000 mg tablets in bottles of 100, 120, or 200.

NOW is a family-owned business that uses strict quality control measures during manufacturing and adheres to cGMP guidelines.

5) California Gold Nutrition Organic Spirulina

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California Gold delivers 500 mg of USDA Organic, USP (United States Pharmacopeial) Verified Spirulina from Arthrospira platensis.

The tablets are produced in a cGMP-certified facility and are free from gluten, soy, and GMOs. You can choose between bottles of 60, 240, and 720 tablets. It’s high-quality spirulina at a great price!

6) Codeage Wildcrafted Sea Moss

Codeage Wildcrafted Sea Moss Powder

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Codeage Wildcrafted Sea Moss isn’t a pure spirulina product, but it’s ideal if you want a comprehensive nutritional powder.

This superfood blend contains raw wildcrafted algae and herbs like Irish moss, bladderwrack, burdock root, and spirulina. It’s also a source of BioPerine®, a black pepper extract known to increase nutrient bioavailability. Plus, it’s non-GMO, keto-friendly, and free from gluten, dairy, soy, fillers, and artificial ingredients.

Codeage is a cutting-edge company that manufactures all its products in a cGMP-certified facility.

How We Ranked

We ranked these supplements, but we want you to decide on the best product for your needs.

Here are the main factors we considered when researching the best spirulina supplements.

Strict Testing Standards

Unscrupulous companies take advantage of the fact that the FDA doesn’t regulate the supplement industry. It makes it easy for dodgy ingredients to make it onto the shelves.

We only choose companies that adhere to cGMP regulations and use strict third-party testing.

Buying from our list ensures you get the best quality and safest spirulina.

Ingredients and Purity

When buying spirulina (or any supplement), you want to consume the best quality.

We looked for spirulina supplements that are grown under the strictest conditions. We also prioritized organic spirulina.


Spirulina is available in capsules, tablets, and powder. That said, capsules and tablets are most convenient and palatable.


The best supplements don’t have to be the most expensive.

We weighed the cost against the number of servings, the dose per serving, and the quality to decide which products are the best value.

What is Spirulina?

Spirulina is a blue-green microalga cultivated from single-celled Arthrospira platensis cyanobacteria. Its blue-green color comes from two pigments: chlorophyll and phycocyanin. (You can check out our article on chlorophyll here).

Health Benefits of Supplementing with Spirulina

Spirulina is a nutrient-rich superfood

The word superfood is thrown around a lot. But spirulina has earned this title. Gram for gram, it’s among the most nutrient-dense foods on earth.

By dry weight, it’s 60-70% absorbable protein. And it has all 8 essential amino acids (practically unheard of for vegan protein).

Spirulina is also rich in iron, copper, magnesium, potassium, manganese, folate, vitamin B1, B2, B3, and essential fatty acids. Plus, it doesn’t have a cellulose cell wall like plants, making it easier to digest and absorb.

Before we get to our list of the best spirulina supplements on the market, let’s explore some health benefits.

Soothes Allergies

Allergy season sucks. Luckily, spirulina has anti-inflammatory properties that may offer relief.

Studies have found spirulina successfully reduces allergic rhinitis symptoms. In fact, 2 grams per day may be more effective than common allergy medications.

Supports Physical Performance

Spirulina may help you perform better during exercise. If you’re hanging out on RFS, I know that’s music to your ears.

This study found spirulina reduced time to exhaustion and increased fat oxidation during cardiovascular exercise.

In addition, spirulina may prevent suppressed immune function caused by strenuous exercise. While rest days are crucial, this may stop you from wiping days off your training schedule unnecessarily.

A quick warning: While spirulina contains all the essential amino acids, I don’t recommend it for meeting your protein goals. You’d need to take a lot of spirulina to get a decent serving of protein (which would become expensive). Instead, stick to concentrated plant-based protein powders to support your gainz.


Is Spirulina a Source of Vitamin B12?

Contrary to popular opinion, spirulina is not a vegan source of vitamin B12.

It contains corrinoid compounds, sometimes called pseudo-vitamin B12. However, these compounds are not biologically active.

Don’t let any health guru convince you spirulina is the only supplement you need. If you’re a vegan or vegetarian, you need to supplement with bioavailable B12.

Does Spirulina Support Heart Health?

Several clinical trials have found spirulina may improve heart disease markers like total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. It may also reduce blood pressure – another factor linked to heart attacks and strokes.

But spirulina is not a magic supplement. Cardiovascular health depends on eating a whole-food diet, regular exercise, quality sleep, and stress management.

Can Spirulina Regulate Blood Sugar Levels?

Balanced blood sugar levels are crucial for steady energy and a clear mind.

This study on people with type-2 diabetes found that 2 grams of spirulina daily for two months improved fasting and postprandial (that means “after meals”) blood glucose levels. It also lowered HbA(1c) levels – a marker of long-term glucose regulation.

However, a recent review found spirulina reduced fasting blood sugar levels but did nothing for postprandial blood sugar or HbA(1c) levels in type-2 diabetics. As of now, the evidence is conflicting.

Can Spirulina Help with Weight Loss?

Spirulina’s excellent amino acid and micronutrient profile may support a healthy metabolism.

This 2020 review paper found that 2–8 grams of spirulina daily reduced body fat, waist circumference, and body mass index.

While we’re not sure of the exact mechanism, it may be linked to lower levels of inflammation and better blood sugar regulation.

Does Spirulina Improve Immunity?

This study found spirulina reduced viral load and improved CD4 counts in people with HIV.

While it’s not a replacement for antiretrovirals, it may offer some much-needed support.

Is Spirulina Good for Iron-Deficiency Anemia?

We don’t know if it improves anemia, but this study found spirulina improved hemoglobin concentration in the elderly. Hemoglobin is the iron-rich protein in red blood cells that carries oxygen to your cells.

What’s the Best Spirulina Dose?

Spirulina doses in the range of 1-10 grams per day have shown promising results in clinical studies. However, it’s a highly concentrated superfood, so we suggest starting on the lower end and working your way up.

Does Spirulina Have Side Effects?

Spirulina is a nutrient-rich microorganism that’s safe for most people. It’s essentially a functional food. There’s minimal risk if you’re taking the suggested dose.

If I Just Take a Greens Supplement, Will I Get Spirulina?

Lots of the best greens powders on the market include spirulina. So you can check out that article for products that will help you get in your spirulina, along with along superfoods. For another superfood we recommend, check out our article on the best sulforaphane supplements.

About the Author

Katherine is a South African-born nutritionist, freelance wellness writer, and rooibos tea enthusiast (iykyk). When she's not researching new "biohacking" trends and writing for her clients, you'll find Katherine swimming at a local Cape Town beach or practicing breathwork at any opportunity.

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