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Dietary supplement

Spirulina & Chlorella Ingredients & Drug Interactions

by Swanson

Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Spirulina & Chlorella is a dietary supplement by Swanson 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 certified organic Chlorella powder, Parry's Vegetarian certified organic Spirulina. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Spirulina & Chlorella by Swanson

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: Parry's Vegetarian certified organic Spirulina and certified organic Chlorella powder. Both are whole-algae supplements — nutrient-dense foods rather than isolated compounds.

The remaining ingredients are inactive (pullulan, brown rice powder, rice bran extract, and rice concentrate), which serve as capsule material and flow agents.

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.

Why this rating?
  • The label markets this product for: Antioxidant support and toxin removal.
  • We looked for evidence on: Cardiovascular disease (CVD), Dyslipidemia, Fatigue, Hyperlipidemia, Malnutrition, Stress — and 3 related terms.
  • The closest evidence on file: Chlorella is rated "Insufficient Reliable Evidence To Rate" for Fatigue (Natural Medicines).
  • Also on file: Chlorella is rated "Insufficient Reliable Evidence To Rate" for Hyperlipidemia.
  • Also on file: Blue-green Algae is rated "Insufficient Reliable Evidence To Rate" for Cardiovascular disease (CVD), Dyslipidemia, Stress, Malnutrition.

For spirulina, the data supports that it's possibly effective for high blood pressure (hypertension). For acne, hay fever, iron deficiency anemia, and arsenic poisoning, the evidence is insufficient to rate.

Chlorella shows possibly effective evidence for pregnancy-related iron deficiency. For brain tumors, fatty liver disease, depression, and fatigue, the evidence is insufficient.

Neither ingredient's effectiveness for other common uses appears in our data.

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 ingredients are generally well tolerated short-term, but a major caution applies to both: product quality and purity vary widely, and contamination with toxins or heavy metals has been documented. The facts note safety data are incomplete for chlorella, and spirulina carries contamination risk.

Common side effects from spirulina include abdominal cramps, bloating, diarrhea, dizziness, fatigue, flatulence, headache, nausea, and vomiting. Chlorella may cause allergic reactions, abdominal cramping, constipation, diarrhea, fatigue, gas, nausea, photosensitivity, and stool discoloration.

Rare but serious reactions (anaphylaxis) have been reported with both. Three cases of mild gum bleeding and one of mild bruising occurred in spirulina users.

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.

Before taking this product, check with your pharmacist if you're on blood thinners or antiplatelet drugs (spirulina may increase bleeding risk), diabetes medications (spirulina may lower blood sugar further), immunosuppressants (spirulina may interfere with them), warfarin specifically (chlorella can reduce its effectiveness), or any drug that makes your skin light-sensitive (chlorella may worsen photosensitization).

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.

Consider this product if you're interested in algae supplements and have no blood-clotting medications, diabetes drugs, immunosuppressants, or photosensitizing medications, and you're not taking warfarin. If you take any prescription medication or have a history of allergies, check your exact drugs with us first.

Be aware that product quality varies — ask your pharmacist about sourcing and purity testing before you buy.

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 Jan 7, 2019.

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 & Chlorella, straight from the product label.

Brand Swanson
Barcode (UPC) 087614060781
Net contents 90 Veggie Capsule(s)
Market status On market
Date entered into DSLD Jan 7, 2019
DSLD ID 184772
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Organic
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 & Chlorella by Swanson, 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:
2 Veggie Capsule(s)
Maximum serving Sizes:
2 Veggie Capsule(s)
Servings per container
45
UPC/BARCODE
087614060781
IngredientAmount% DV
Parry's Vegetarian certified organic Spirulina400 mg--
certified organic Chlorella powder400 mg--

Other ingredients: Pullulan, organic Brown Rice powder, organic Rice Bran extract, organic Rice concentrate

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.
Formulation

Two certified organic superfoods combined as one powerful supplement

Certified Organic by Minnesota Crop Improvement Association (MCIA), St. Paul, MN 55108.

General Statements

Boosts antioxidant activity Supports toxin removal Science-backed Quality Since 1969

Antioxidant Support 400 mg each Green Foods Formula

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take two capsules one to three times per day with food and water.

Brand IP Statement(s)

Parry's Vegetarian Certified Organic Spirulina is a trademark of Parry Nutraceuticals, Ltd.

Precautions

Warning: For adults only.

Consult your physician before using this or any product if you are pregnant or nursing, taking medication or have a medical condition.

Keep out of reach of children.

Do not use if seal is broken.

Storage

Store in a cool, dry place.

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.

Formula

Made with Organic Spirulina & Chlorella

FDA Statement of Identity

Dietary Supplement

General

SWR078 Rev 0 05 03 18

See for yourself

Spirulina & Chlorella by Swanson label

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

What’s inside

The Ingredients in Spirulina & Chlorella by Swanson

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

Serving size2 Veggie Capsule(s) Dosage formCapsule Servings per container45 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.

400 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...

Parry's Vegetarian certified organic Spirulina monograph & interactions

Certified organic Chlorella powder

Interacts with
337 drugs
400 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...

Certified organic Chlorella powder monograph & interactions

Other (inactive) ingredients: Pullulan, Organic Brown Rice powder, Organic Rice Bran extract, Organic Rice concentrate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Spirulina & Chlorella by Swanson Drug Interactions

Want to check YOUR meds against Spirulina & 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

Each ingredient & the kinds of drugs it affects

For each ingredient in Spirulina & 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.

certified organic Chlorella powder2 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

Parry's Vegetarian certified organic 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 & Chlorella, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
swanson.com
Pharmacist Counseling Corner

Spirulina & Chlorella by Swanson: Common Questions

Does Spirulina & Chlorella by Swanson interact with any medications?
Yes. Based on its ingredients, Spirulina & 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 & 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 on warfarin?
Not without talking to your doctor or pharmacist first. Chlorella contains vitamin K, which can reduce how well warfarin works — there's at least one case report of warfarin becoming ineffective after someone started chlorella. You'll need personalized advice.
Can I take this if I'm on diabetes medication?
Not without checking with your pharmacist first. Spirulina can lower blood sugar on its own, so combining it with diabetes drugs raises your risk of low blood sugar (hypoglycemia). Your doctor may need to adjust your medication.
Is this safe during pregnancy?
The facts don't include safety data for spirulina in pregnancy or lactation. For chlorella, there's no safety information on file either. Talk with your doctor or pharmacist — they can help you decide based on your individual situation.
What are the most common side effects?
Digestive upset is most common — abdominal cramps, bloating, diarrhea, gas, nausea, and vomiting, especially in the first two weeks. Spirulina may also cause dizziness, fatigue, or headache. Chlorella may cause constipation or stool discoloration. These are usually mild and temporary.
Does spirulina really lower blood pressure?
The data shows spirulina is possibly effective for high blood pressure. For other uses listed — acne, hay fever, iron deficiency, arsenic poisoning — the evidence is insufficient to say whether it works.
Is this product pure and safe from contamination?
The facts warn that product quality and purity vary widely, and contamination with toxins or heavy metals has been documented. Ask your pharmacist about the specific source and testing done on the brand you're considering.

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

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

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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 & Chlorella label
Sources

Sources & How We Checked

Spirulina & 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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