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Dietary supplement

Spirulina And Chlorella Ingredients & Drug Interactions

by Onnit

Tablet Or Pill Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Spirulina And Chlorella is a dietary supplement by Onnit with 2 active ingredients. Its ingredients are commonly taken for general nutrition and energy, antioxidant support, cholesterol and metabolic health.Based on those ingredients, 626 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Chlorella, Spirulina. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Spirulina And Chlorella by Onnit

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

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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains 2 active ingredients: spirulina and chlorella, both algae-based supplements. The tablet also includes several inactive ingredients — dicalcium phosphate, pregelatinized starch, and croscarmellose sodium — which are standard binders and tablet aids.

Does it work?

Moderate evidence
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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Moderate

Some clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Pregnancy-related iron deficiency — rated "Possibly Effective" (Chlorella) (Natural Medicines).
  • On file: Hypertension — rated "Possibly Effective" (Blue-green Algae) (Natural Medicines).

The evidence varies by ingredient and use. For spirulina, there's possibly effective evidence for high blood pressure.

For chlorella, there's possibly effective evidence for pregnancy-related iron deficiency. Both ingredients show insufficient reliable evidence for other conditions we hold data on — including acne, hay fever, general iron deficiency anemia, and fatigue — meaning the research so far hasn't established whether they work.

The evidence, ingredient by ingredient Blue-green Algae Chlorella

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Both spirulina and chlorella are generally well tolerated in the short term, but quality and purity vary widely among products, and contamination with toxins or heavy metals is a documented concern. Common side effects from both include abdominal cramping, bloating, diarrhea, nausea, and fatigue — especially in the first two weeks.

Allergic reactions, including rashes and in rare cases anaphylaxis, have been reported. Spirulina may also cause mild gum bleeding or bruising.

Chlorella can trigger photosensitivity (sun-induced skin reactions) in some people. The safety data for both during pregnancy and breastfeeding is limited — chlorella is rated possibly safe in pregnancy, but there isn't enough information on file for spirulina in either case.

Side effects, ingredient by ingredient Blue-green Algae Chlorella

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?
  • 2 of the 2 matched ingredients can interact with medications — Chlorella, 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: 626 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.

Check your medications before taking this product if you use blood thinners or antiplatelet drugs (spirulina may increase bleeding risk), immune-suppressing drugs (spirulina may interfere with them), diabetes medications (spirulina may increase low blood sugar risk), drugs that cause photosensitivity (chlorella may add to that effect), or warfarin specifically (chlorella's vitamin K content can reduce warfarin effectiveness). These are Moderate-severity interactions — not guaranteed to occur, but worth reviewing with your own pharmacist or doctor.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

These algae-based supplements may be worth considering if you're interested in their possibly effective uses — high blood pressure for spirulina, pregnancy-related iron deficiency for chlorella — but the interaction profile is extensive and warrants a close look at your current medications. Quality and contamination risk are genuine concerns with algae products.

Talk with your doctor or pharmacist about whether this product fits your health plan and medications before you start.

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

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 22, 2016.

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 And Chlorella, straight from the product label.

Brand Onnit
Barcode (UPC) 819444010151
Net contents 80 Tablet(s)
Market status On market
Date entered into DSLD Sep 22, 2016
DSLD ID 64594
Product type Non-nutrient/non-botanical
Supplement form Tablet Or Pill
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten 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 And Chlorella by Onnit, 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:
4 Tablet(s)
Maximum serving Sizes:
4 Tablet(s)
Servings per container
20
UPC/BARCODE
819444010151
IngredientAmount% DV
Spirulina1000 mg--
Chlorella1000 mg--

Other ingredients: Dicalcium Phosphate, pregelatinized Starch, Croscarmellose Sodium

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.
Suggested/Recommended/Usage/Directions

Suggested Use: Adults, as a dietary supplement, take four tablets, preferably with a meal, up to two times daily. Do not exceed eight tablets in any 24-hour period.

Precautions

Consult a medical doctor before taking this or any other nutritional supplement if you are pregnant, nursing, have or suspect a medical condition or are taking any medications.

Keep out of reach of children.

Storage

Store in a cool, dry place.

Formulation

Vegan

Non GMO no Soy no Gluten

General

R150510-167

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Brand IP Statement(s)

Copyright 2015 Onnit Labs, LLC. All rights reserved.

FDA Statement of Identity

Dietary Supplement

See for yourself

Spirulina And Chlorella by Onnit label

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

What’s inside

The Ingredients in Spirulina And Chlorella by Onnit

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size4 Tablet(s) Dosage formTablet Or Pill Servings per container20 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Spirulina

Interacts with
327 drugs
1000 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 monograph & interactions

Chlorella

Interacts with
337 drugs
1000 mg per serving

Chlorella is a nutrient-rich freshwater green algae taken as a supplement for general wellness, immune support, and 'detox.' Some small studies sugges...

Chlorella monograph & interactions

Other (inactive) ingredients: Dicalcium Phosphate, Pregelatinized Starch, Croscarmellose Sodium. These complete the product’s ingredient list but are not active constituents.

Interaction report

Spirulina And Chlorella by Onnit Drug Interactions

Want to check YOUR meds against Spirulina And Chlorella?

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
626Drugs
626 Moderate

Ingredients driving the most interactions

Chlorella 337
Spirulina 327

Each ingredient & the kinds of drugs it affects

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

Chlorella2 drug types · 337 drugs

Photosensitizing Drugs

Theoretically, chlorella might have additive effects with photosensitizing drugs.
Chlorella has been reported to cause photosensitization. In five case reports, patients who had ingested chlorella exhibited swelling followed by erythematopurpuric lesions on sun-exposed areas of the body. Theoretically, concomitant use with photosensitizing drugs may exacerbate effects.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, chlorella might reduce the clinical effects of warfarin.
Chlorella contains significant amounts of vitamin K. There is at least one case report of warfarin therapy becoming sub-therapeutic after initiation of chlorella supplements.

Likelihood Possible Evidence D

Spirulina3 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
The maker

Brand information

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

Onnit

See all Onnit products
Name
Onnit Labs, LLC
City
Austin
State
Texas
ZipCode
78744
Phone Number
(855) 666-4899
Pharmacist Counseling Corner

Spirulina And Chlorella by Onnit: Common Questions

Does Spirulina And Chlorella by Onnit interact with any medications?
Yes. Based on its ingredients, Spirulina And Chlorella has a known interaction with 626 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Spirulina And Chlorella contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
Can I take this if I'm pregnant or breastfeeding?
Chlorella is rated possibly safe in pregnancy, but there isn't enough safety data on file for spirulina during pregnancy or breastfeeding for either ingredient. Talk with your doctor or pharmacist about whether this product is right for you during these periods — it's a personal medical decision based on your full picture.
What are the most common side effects?
Both ingredients can cause abdominal cramping, bloating, diarrhea, nausea, and fatigue, especially in the first two weeks. Allergic reactions including rashes have been reported less commonly, and very rarely anaphylaxis. Spirulina may cause mild gum bleeding or bruising, and chlorella can trigger sun-sensitive skin reactions in some people.
Does this actually work for anything?
Spirulina has possibly effective evidence for high blood pressure. Chlorella has possibly effective evidence for pregnancy-related iron deficiency. For other uses like acne, hay fever, or fatigue, the evidence is insufficient — we don't know yet whether they work.
I'm concerned about purity — is this product clean?
Quality and purity vary widely among algae products, and contamination with toxins or heavy metals is a documented safety concern. The product facts advise caution on this front. You may want to ask the manufacturer about third-party testing or certificates of analysis for this batch.
What's the difference between spirulina and chlorella?
Both are algae, but spirulina is blue-green algae and chlorella is green algae. They have different interaction profiles and different possible uses — spirulina for blood pressure, chlorella for pregnancy iron deficiency — and different common side effects, though both can cause digestive upset early on.
Is this safe to take with my other supplements?
The documented interactions listed on this page apply to medications, not other supplements. If you're combining multiple supplements, mention all of them to your pharmacist or doctor to make sure there are no conflicts — they can review your full regimen together.

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

Not sure if Spirulina And Chlorella is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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 And Chlorella label
Sources

Sources & How We Checked

Spirulina And Chlorella'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 35 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 →

Chlorella 13 references
  1. Peirce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York, NY: William Morrow and Co., 1999.
  2. Ng TP, Tan WC, Lee YK. Occupational asthma in a pharmacist induced by chlorella, a unicellular algae preparation. Resp Med 1994;88:555-7. PubMed
  3. Jitsukawa K, Suizu R, Hidano A. Chlorella photosensitization. New phytophotodermatosis. Int J Dermatol 1984;23:263-8. PubMed
  4. Merchant RE, Carmack CA, Wise CM. Nutritional supplementation with Chlorella pyrenoidosa for patients with fibromyalgia syndrome: a pilot study. Phytother Res 2000;14:167-73.
  5. Merchant RE, Rice CD, Young HF. Dietary Chlorella pyrenoidosa for patients with malignant glioma: effects on immunocompetence, quality of life, and survival. Phytother Res 1990;4:220-31.
  6. Halperin SA, Smith B, Nolan C, et al. Safety and immunoenhancing effect of a Chlorella-derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial. CMAJ 2003;169:111-7..
  7. Ohtake, T., Negishi, K., Okamoto, K., Oka, M., Maesato, K., Moriya, H., and Kobayashi, S. Manganese-induced Parkinsonism in a patient undergoing maintenance hemodialysis. Am J Kidney Dis 2005;46(4):749-753. PubMed
  8. Ng, T. P., Tan, W. C., and Lee, Y. K. Occupational asthma in a pharmacist induced by Chlorella, a unicellular algae preparation. Respir.Med. 1994;88(7):555-557. PubMed
  9. Ohkawa, S., Yoneda, Y., Ohsumi, Y., and Tabuchi, M. [Warfarin therapy and chlorella]. Rinsho Shinkeigaku 1995;35(7):806-807.
  10. Azocar J, Diaz A. Efficacy and safety of chlorella supplementation in adults with chronic hepatitis C virus infection. World J Gastroenterol 2013;19(7):1085-90. PubMed
  11. Panahi Y, Badeli R, Karami GR, Badeli Z, Sahebkar A. A randomized controlled trial of 6-week Chlorella vulgaris supplementation in patients with major depressive disorder. Complement Ther Med 2015;23(4):598-602. PubMed
  12. Nakano S, Takekoshi H, Nakano M. Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant women. Plant Foods Hum Nutr 2010;65(1):25-30. PubMed
  13. Yavasoglu I, Turgutkaya A, Bolaman Z. Chlorella-induced thrombocytopenia. Sao Paulo Med J 2018;136(6):602-3. PubMed

See these in context on the Chlorella 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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