Drug & supplement interaction

Blue-green Algae + Guaifenesin, Phenylephrine, Phenylpropanolamine

Guaifenesin, Phenylephrine, Phenylpropanolamine brand names: Dura Gest, Entex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Guaifenesin, Phenylephrine, Phenylpropanolamine and Blue-green Algae in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Blue-green Algae safety at a glance

Blue-green Algae overall Use caution Quality varies and some products can be contaminated with toxins or heavy metals.
Pregnancy Avoid Not enough safety data and contamination risk; best to avoid.
Breastfeeding Avoid Safety is unknown and contamination is a concern; best to avoid.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Guaifenesin, Phenylephrine, Phenylpropanolamine and Blue-green Algae? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Guaifenesin, Phenylephrine, Phenylpropanolamine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Guaifenesin, Phenylephrine, Phenylpropanolamine is filed under 4 classifications — including phenylpropanolamine, alpha-adrenergic agonists, stimulant drugs. Blue-green Algae has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and immunosuppressants (moderate) — and none of Guaifenesin, Phenylephrine, Phenylpropanolamine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Blue-green Algae Does Interact With Other Medications

Blue-green Algae has 327 moderate known drug interactions in our database — Guaifenesin, Phenylephrine, Phenylpropanolamine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 327 No known interaction 2,503 (incl. Guaifenesin, Phenylephrine, Phenylpropanolamine)
Taking anything else?

Check Another of Your Medications Against Blue-green Algae

Covers the 2,830 medications we’ve checked against Blue-green Algae. Pick one to open its full report.

What to actually watch for

What Blue-green Algae Itself Has Been Linked To

This is not an interaction — nothing below involves Guaifenesin, Phenylephrine, Phenylpropanolamine. It is the side-effect record for Blue-green Algae on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Blue-green Algae, this list is the first place to look. 3 entries are worth acting on rather than waiting out — marked below.

  • Severe muscle breakdown / Muscle weakness Worth acting on Additional detail

    “Orally, after a 49-year-old woman stopped taking a spirulina blue-green algae supplement (species and dose unknown), the patient experienced inflammatory myopathy with muscle weakness and elevated creatine kinase. The condition resolved with corticosteroid and cyclophosphamide treatment.”

    Blue-green Algae · Natural Medicines adverse-effect record, reported in muscle breakdown.

    2 sources cited
    1. 75936. 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
    2. 75922. 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
  • Wheezing / Shortness of breath / A severe allergic reaction / Hives / An allergic reaction Worth acting on Additional detail

    “Orally, urticarial rashes and pruritus have occurred as part of generalized allergic reactions to blue-green algae.

    In one case report, a 14-year-old male experienced anaphylaxis with urticaria, lip edema, and asthma 6 hours after taking five tablets of spirulina blue-green algae (A. platensis, strength unknown). He had a positive skin prick test.”

    Blue-green Algae · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    3 sources cited
    1. 91706. 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
    2. 91711. 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
    3. 91712. 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
  • Bleeding or bruising Worth acting on Additional detail

    “Orally, three cases of mild gum bleeding and one case of mild bruising have been reported in patients taking spirulina blue-green algae (Cyactiv, Cerule LLC) 2.3 grams daily (containing approximately 1 gram of phycocanin) for 2 weeks.”

    Blue-green Algae · Natural Medicines adverse-effect record, reported in bleeding.

    1 source cited
    1. 97202. 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
  • Bloating or gas Additional detail

    “Orally, gastrointestinal complaints are amongst the most common adverse effects associated with spirulina blue-green algae, including nausea, vomiting, diarrhea, and abdominal cramps. Similarly, common adverse effects associated with the blue-green algae species Aphanizomenon flos-aquae are stomach upset, flatulence, diarrhea, and bloating.”

    Blue-green Algae · Natural Medicines adverse-effect record, reported in diarrhea.

    5 sources cited
    1. 19272. 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
    2. 75924. 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.
    3. 91713. 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
    4. 109969. 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
    5. 14842. 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
  • Stomach upset Additional detail

    Recorded for Blue-green Algae in the same Natural Medicines adverse-effect record shown under Bloating or gas above.

Showing the 10 most notable of 20 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Blue-green Algae — expand a row for the licensed statement it rests on. We haven’t matched Guaifenesin, Phenylephrine, Phenylpropanolamine to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Guaifenesin, Phenylephrine, Phenylpropanolamine.

Everything else you take

See Every Supplement That Interacts With Guaifenesin, Phenylephrine, Phenylpropanolamine

This page covers Blue-green Algae only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guaifenesin, Phenylephrine, Phenylpropanolamine page lists 62 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Peyote (major), Rauvolfia Vomitoria (major) and Sida Cordifolia (major).

By severity: 5 major · 44 moderate · 13 minor.

From our pharmacist’s overview on the Guaifenesin, Phenylephrine, Phenylpropanolamine page

“Entex (guaifenesin, phenylephrine, phenylpropanolamine) treats congestion with two decongestants that behave like mild stimulants, squeezing blood vessels and pushing blood pressure up. That built-in stimulant effect is why its list of 62 supplement interactions deserves genuine care, and why five entries rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Guaifenesin, Phenylephrine, Phenylpropanolamine interaction page

One more smart check

Taking Blue-green Algae as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3,180 real supplement products containing Blue-green Algae, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Blue-green Algae. Even though Blue-green Algae itself has no known interaction with Guaifenesin, Phenylephrine, Phenylpropanolamine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Blue-green Algae
Top 10%

#78 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Guaifenesin, Phenylephrine, Phenylpropanolamine
Steady interest

#2,148 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Blue-green Algae reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Blue-green Algae

What is Blue-green Algae?

Blue-green Algae
  • General nutrition and energy
  • Antioxidant support
  • Cholesterol and metabolic health
  • Immune support
  • Weight management

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 health claims is limited, and some products can be contaminated with toxins or heavy metals, so quality testing matters. Talk to your pharmacist or doctor before using, especially during pregnancy or breastfeeding.

Whole dried microorganism (algae biomass) · Tablets, capsules, powder, flakes, and liquid extracts

An interaction check asks whether these two react with each other — it does not ask whether Blue-green Algae is a good idea for someone in your situation. Here is what our Blue-green Algae record says about it on its own.

Blue-green Algae: dosing

There is no official, standardized dose for blue-green algae, and the amount varies a lot from product to product. Different species and forms (tablet, powder, or liquid) also differ in strength.The safest approach is to follow the directions on the product label and not exceed them.

From our Blue-green Algae monograph — the full record covers uses, side effects and every documented interaction.

Read the full Blue-green Algae monograph & all interactions
Keep checking

Other Drugs & Blue-green Algae

Browse every other medication we’ve checked against Blue-green Algae — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
327Moderate
0Minor
2,502No known interaction
327 Moderate 2,502 No interaction
Moderate

327 interactions

Showing 60 of 327 moderate interactions — see all 327 on the Blue-green Algae page.

No interaction 2,502 drugs checked — show the list

We also checked Blue-green Algae against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,502 medications checked with no known interaction — see the full Blue-green Algae list.

See the full Blue-green Algae interactions page
See every supplement checked against Guaifenesin, Phenylephrine, Phenylpropanolamine, ranked by severity
Evidence & sources

Blue-green Algae References

The 22 references that drive our Blue-green Algae monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine Together: Common Questions

Is it safe to take Blue-green Algae with Guaifenesin, Phenylephrine, Phenylpropanolamine?
We do not list a known interaction between Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Blue-green Algae and Guaifenesin, Phenylephrine, Phenylpropanolamine combination checked?
Interactions in our licensed database are recorded against drug classes. Guaifenesin, Phenylephrine, Phenylpropanolamine is filed under 4 classifications, and Blue-green Algae has documented interactions with 3 drug classes — none of Guaifenesin, Phenylephrine, Phenylpropanolamine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Blue-green Algae interact with any other medications?
Yes. Blue-green Algae has 327 documented drug interactions in our database — Guaifenesin, Phenylephrine, Phenylpropanolamine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Guaifenesin, Phenylephrine, Phenylpropanolamine interact with any supplements?
Yes. Guaifenesin, Phenylephrine, Phenylpropanolamine has documented interactions with 62 supplements in our database — Blue-green Algae is not one of them. The Guaifenesin, Phenylephrine, Phenylpropanolamine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Blue-green Algae monograph Uses, safety profile, and every drug interaction in one place Guaifenesin, Phenylephrine, Phenylpropanolamine supplement interactions Every supplement checked against Guaifenesin, Phenylephrine, Phenylpropanolamine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 22 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Guaifenesin, Phenylephrine, Phenylpropanolamine and Blue-green Algae?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.