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Dietary supplement

Spirulina Ingredients & Drug Interactions

by GNC SuperFoods

Spirulina label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Spirulina against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Spirulina is a dietary supplement by GNC SuperFoods with 1 active ingredient. Its ingredients are commonly taken for general nutrition and energy, antioxidant support, cholesterol and metabolic health.Based on those ingredients, 327 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Spirulina powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Spirulina by GNC SuperFoods

Ask about any prescription or over-the-counter medication and we check it for interactions with Spirulina by GNC SuperFoods — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Spirulina by GNC SuperFoods

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: spirulina powder, a blue-green algae. It's a nutrient-dense whole food that's used in supplements for a range of purposes, though the strength of evidence varies considerably across them.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Blue-green Algae's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: Natural source of essential nutrients and phytonutrients.
  • We looked for evidence on: Malnutrition, Athletic performance, General nutrition, Energy support.
  • The closest evidence on file: Blue-green Algae is rated "Insufficient Reliable Evidence To Rate" for Athletic performance (Natural Medicines).
  • Also on file: Blue-green Algae is rated "Insufficient Reliable Evidence To Rate" for Malnutrition.

Spirulina is possibly effective for high blood pressure (hypertension). For acne, allergic rhinitis (hay fever), iron deficiency anemia, and arsenic poisoning, the evidence we hold isn't strong enough to rate it.

Those are areas where more research is needed to know whether it actually works.

The evidence, ingredient by ingredient Blue-green Algae

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Spirulina is generally well tolerated when taken by mouth. The most common side effects reported are abdominal cramps, bloating, diarrhea, dizziness, fatigue, flatulence, headache, nausea, and vomiting.

Allergic reactions, including rashes and itching, have occurred; one case report documented a severe allergic reaction (anaphylaxis) in a teenager, though this is rare. A few cases of mild gum bleeding and bruising have been reported in people taking 2.3 grams daily.

One important safety note: spirulina quality varies widely, and some products can be contaminated with toxins or heavy metals. There isn't enough safety data on spirulina itself in pregnancy and lactation; talk with your doctor or pharmacist about whether it's right for you if you're pregnant or breastfeeding.

Side effects, ingredient by ingredient Blue-green Algae

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Blue-green Algae.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 327 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you start, double-check with your pharmacist if you're taking blood thinners or antiplatelet drugs (Moderate risk), diabetes medications (Moderate risk), or immunosuppressant drugs (Moderate risk). No interactions are documented for the other medications this product might affect, but the 322-medication count includes theoretical interactions that haven't shown up in most people.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Spirulina may be worth considering if you're looking at it for high blood pressure, but check your blood thinners, diabetes medications, and any immunosuppressants with your pharmacist first. Quality and contamination are real concerns with blue-green algae products — ask your pharmacist which brands are most reliable.

If you have any food or algae allergies, be especially cautious.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jul 25, 2017.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Spirulina, straight from the product label.

Brand GNC SuperFoods
Barcode (UPC) 048107116163
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Jul 25, 2017
DSLD ID 74778
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Spirulina by GNC SuperFoods, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
UPC/BARCODE
048107116163
IngredientAmount% DV
Spirulina powder500 mg--

Other ingredients: Gelatin, Cellulose, Stearic Acid

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Precautions

Keep out of reach of children.

Warning: Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition.

Discontinue use two weeks prior to surgery.

Storage

Store in a cool, dry place.

Formula

With Phytonutrients

Spirulina is a blue-green microalgae that is a natural source of essential phytonutrients, protein and amino acids.

FDA Statement of Identity

Dietary Supplement

General

CODE 456802 BRG

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take one to three capsules one half hour before each meal.

General Statements

Conforms to USP <2091> for weight. Meets USP <2040> disintegration.

Actual size

Formulation

No sugar, no starch, no artificial colors, no artificial flavors, sodium free, no wheat, gluten free, no corn, no soy, no dairy, yeast free.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Spirulina by GNC SuperFoods label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Spirulina label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Spirulina by GNC SuperFoods

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Spirulina powder

Interacts with
327 drugs
500 mg per serving

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and...

Spirulina powder monograph & interactions

Other (inactive) ingredients: Gelatin, Cellulose, Stearic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Spirulina by GNC SuperFoods Drug Interactions

Want to check YOUR meds against Spirulina?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
327Drugs
327 Moderate

Ingredients driving the most interactions

Spirulina powder 327

Individual Drug Interactions

The ingredients in Spirulina interact with 327 drugs. Click any drug to see the details.

1 of the 1 ingredient in Spirulina interact with drugs. Each result below shows which ingredient is responsible. Spirulina powder

Each ingredient & the kinds of drugs it affects

For each ingredient in Spirulina with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Spirulina powder3 drug types · 327 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, spirulina blue-green algae might increase the risk of bleeding if used with other anticoagulant or antiplatelet drugs. However, this is unlikely.
Spirulina blue-green algae have shown antiplatelet and anticoagulant effects in vitro. However, one preliminary study in 24 patients receiving spirulina blue-green algae 2.3 grams daily for 2 weeks showed no effect on platelet activation or measures of clotting time.

Likelihood Unlikely Evidence D
Antidiabetes Drugs

Theoretically, taking blue-green algae with antidiabetes drugs might increase the risk of hypoglycemia.
Human research shows that spirulina blue-green algae can have hypoglycemic effects in patients with diabetes, at least some of whom were using antidiabetes drugs. However, blue-green algae does not seem to improve glycated hemoglobin (HbA1c) levels in patients with diabetes. A meta-analysis of animal studies also suggests that spirulina blue-green algae have hypoglycemic effects.

Likelihood Possible Evidence B
Immunosuppressants

Theoretically, concurrent use of blue-green algae might interfere with immunosuppressive therapy.
Blue-green algae have been shown to stimulate the immune system.

Likelihood Possible Evidence D
Spirulina powder full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Spirulina, from the product label.

GNC SuperFoods

See all GNC SuperFoods products
Name
General Nutrition Corporation
City
Pittsburgh
State
PA
ZipCode
15222
Phone Number
1-888-462-2548
Web Address
www.gnc.com
Pharmacist Counseling Corner

Spirulina by GNC SuperFoods: Common Questions

Does Spirulina by GNC SuperFoods interact with any medications?
Yes. Based on its ingredients, Spirulina has a known interaction with 327 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Spirulina contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does spirulina actually work for high blood pressure?
According to the data we hold, spirulina is possibly effective for high blood pressure. That means there's some evidence it helps, but it's not definitive. Talk with your doctor about whether it makes sense alongside your other treatments.
What side effects might I experience?
Most people tolerate it well, but digestive upset is common — think bloating, diarrhea, nausea, and gas. You might also notice dizziness, headache, or fatigue. Allergic reactions including rashes and itching are less common but do happen.
Is it safe to take spirulina while I'm pregnant or breastfeeding?
There isn't enough safety data to know whether it's safe during pregnancy or lactation. Talk with your doctor or pharmacist for personalized advice, especially since contamination is also a concern with blue-green algae products.
Why does this product say to avoid it if contamination is a risk?
Spirulina quality varies a lot because it's grown in water and can pick up toxins or heavy metals. The safety notes reflect that contamination risk. Choosing a reputable brand and asking your pharmacist to recommend one can help lower that concern.
Can I take this if I have a shellfish or seaweed allergy?
That's a conversation to have with your pharmacist or doctor before you start. One case of severe allergic reaction to spirulina has been reported, and if you're already allergic to aquatic plants or organisms, your risk might be higher.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Spirulina is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Spirulina label
Go deeper

The Full Monographs Behind Spirulina’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Blue-green Algae

Interacts with 327 drugs

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and general wellness. Evidence for most heal...

Read the full Blue-green Algae monograph →
Sources

Sources & How We Checked

Spirulina's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 22 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Blue-green Algae 22 references
  1. Jensen GS, Ginsberg DJ, Huerta P, et al. Consumption of Aphanizomenon flos-aquae has rapid effects on the circulation and function of immune cells in humans. A novel approach to nutritional mobilization of the immune system. JANA 2000;2:50-6.
  2. Iwasa M, Yamamoto M, Tanaka Y, et al. Spirulina-associated hepatotoxicity. Am J Gastroenterol 2002;97:3212-13. PubMed
  3. Hayashi O, Katoh T, Okuwaki Y. Enhancement of antibody production in mice by dietary Spirulina platensis. J Nutr Sci Vitaminol (Tokyo) 1994;40:431-41.. PubMed
  4. Vitale S, Miller NR, Mejico LJ, et al. A randomized, placebo-controlled, crossover clinical trial of super blue-green algae in patients with essential blepharospasm or Meige syndrome. Am J Ophthalmol 2004;138:18-32. PubMed
  5. Mani UV, Desai S, Iyer U. Studies on the long-term effect of spirulina supplementation on serum lipid profile and glycated proteins in NIDDM patients. J Nutraceut 2000;2(3):25-32. DOI
  6. Chiu HF, Yang SP, Kuo YL, et al. Mechanisms involved in the antiplatelet effect of C-phycocyanin. Br J Nutr 2006;95:435-40. PubMed
  7. Hsiao G, Chou PH, Shen MY, et al. C-phycocyanin, a very potent and novel platelet aggregation inhibitor from Spirulina platensis. J Agric Food Chem 2005;53:7734-40.
  8. Katz M, Levine AA, Kol-Degani H, Kav-Venaki L. A compound herbal preparation (CHP) in the treatment of children with ADHD: a randomized controlled trial. J Atten Disord 2010;14:281-91. PubMed
  9. Madhyastha, H. K., Radha, K. S., Sugiki, M., Omura, S., and Maruyama, M. Purification of c-phycocyanin from Spirulina fusiformis and its effect on the induction of urokinase-type plasminogen activator from calf pulmonary endothelial cells. Phytomedicine PubMed
  10. Mazokopakis, E. E., Karefilakis, C. M., Tsartsalis, A. N., Milkas, A. N., and Ganotakis, E. S. Acute rhabdomyolysis caused by Spirulina (Arthrospira platensis). Phytomedicine. 2008;15(6-7):525-527. PubMed
  11. Halidou, Doudou M., Degbey, H., Daouda, H., Leveque, A., Donnen, P., Hennart, P., and Dramaix-Wilmet, M. [The effect of spiruline during nutritional rehabilitation: systematic review]. Rev.Epidemiol.Sante Publique 2008;56(6):425-431.
  12. Konno, T., Umeda, Y., Umeda, M., Kawachi, I., Oyake, M., and Fujita, N. [A case of inflammatory myopathy with widely skin rash following use of supplements containing Spirulina]. Rinsho Shinkeigaku 2011;51(5):330-333. PubMed
  13. Le TM, Knulst AC, Röckmann H. Anaphylaxis to Spirulina confirmed by skin prick test with ingredients of Spirulina tablets. Food Chem Toxicol 2014;74:309-10. PubMed
  14. Rzymski P, Niedzielski P, Kaczmarek N, Jurczak T, Klimaszyk P. The multidisciplinary approach to safety and toxicity assessment of microalgae-based food supplements following clinical cases of poisoning. Harmful Algae 2015;46:34-42. DOI
  15. Petrus M, Culerrier R, Campistron M, et al. First case report of anaphylaxis to spirulin: identification of phycocyanin as responsible allergen. Allergy 2010;65(7):924-5. PubMed
  16. Marles RJ, Barrett ML, Barnes J, et al. United States Pharmacopeia safety evaluation of spirulina. Crit Rev Food Sci Nutr 2011;51(7):593-604. PubMed
  17. Majdoub H, Ben Mansour M, Chaubet F, et al. Anticoagulant activity of a sulfated polysaccharide from the green alga Arthrospira platensis. Biochim Biophys Acta 2009;1790(10):1377-81. PubMed
  18. Cha BG, Kwak HW, Park AR, et al. Structural characteristics and biological performance of silk fibroin nanofiber containing microalgae spirulina extract. Biopolymers 2014;101(4):307-18. PubMed
  19. Jensen GS, Drapeau C, Lenninger M, Benson KF. Clinical safety of a high dose of phycocyanin-enriched aqueous extract from Arthrospira (Spirulina) platensis: results from a randomized, double-Blind, placebo-controlled study with a focus on anticoagulant ac
  20. Hamedifard Z, Milajerdi A, Reiner Z, Taghizadeh M, Kolahdooz F, Asemi Z. The effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized con
  21. Moradi S, Zobeiri M, Feizi A, Clark CCT, Entezari MH. The effects of spirulina (Arthrospira platensis) supplementation on anthropometric indices, blood pressure, sleep quality, mental health, fatigue status and quality of life in patients with ulcerative
  22. Ghanbari F, Amerizadeh A, Behshood P, Moradi S, Asgary S. Effect of microalgae arthrospira on biomarkers of glycemic control and glucose metabolism: a systematic Review and meta-analysis. Curr Probl Cardiol 2022;47(10):100942. PubMed

See these in context on the Blue-green Algae monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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