Drug & supplement interaction

Blue-green Algae + Minocycline

Minocycline brand names: Vectrin, Dynacin, Minocin, Minocin IV, Solodyn, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Blue-green Algae has a moderate interaction with Minocycline. Theoretically, spirulina blue-green algae might increase the risk of bleeding if used with other anticoagulant or antiplatelet drugs.

Read the full interaction report
SeverityModerate
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Blue-green Algae and Minocycline

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Minocycline

Minocycline falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Blue-green Algae interacts with.

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.
Severity Moderate Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the honest picture: this concern comes from blue-green algae like spirulina, not really from minocycline itself. In lab dishes, spirulina has shown mild blood-thinning and anti-platelet effects, so on paper there's a thought it could add to bleeding risk when combined with medicines that slow clotting.

The catch is that minocycline isn't an anticoagulant or antiplatelet drug at all, so this category-level worry mostly doesn't apply to it. Minocycline's own typical effects are things like dizziness, stomach upset, and sun sensitivity, not bleeding. The evidence here is purely theoretical, and a small human study showed no real effect on clotting. Still, if you take an actual blood thinner alongside, or you have any bleeding concerns, it's worth a quick chat with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. 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.
  3. 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
  4. 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
  5. 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
  6. 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

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Blue-green Algae Also Interacts With Other Medications

Blue-green Algae has 326 moderate known drug interactions in our database — the Minocycline one above is one of them. If you take anything else, check it against the full list below.

Moderate 326 No known interaction 2,504 (incl. Minocycline)
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.

From our Q&A

Questions About Blue-green Algae or Minocycline

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Blue-green Algae or Minocycline, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Minocycline

This page covers Blue-green Algae only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Minocycline page lists 331 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Oleander (major).

By severity: 9 major · 290 moderate · 32 minor.

From our pharmacist’s overview on the Minocycline page

“This is one of the longer interaction lists I review, and with minocycline it earns real care rather than a shrug. Most entries pair this tetracycline antibiotic, taken for acne and other infections, with supplements that raise bleeding risk, and a second sizable group, beer and wine included, can add strain on the liver.”

Reviewed by 2 · Jul 18, 2026

Open the Minocycline 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. Your product may carry other ingredients that interact with Minocycline too, on top of Blue-green Algae — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Blue-green Algae and Minocycline 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 Minocycline
Top half

#819 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.

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.

Read the full Blue-green Algae monograph & all interactions
Medication

About Minocycline

What Is Minocycline Used For?

Brand names: Vectrin, Dynacin, Minocin, Minocin IV, Solodyn, Acnamino MR, Minocin MR, Sebomin MR, Aknemin, Arestin Miscrosperes, Amzeeq, Zilxi

Oral and intravenous minocycline products treat many serious bacterial infections, including Rocky Mountain spotted fever, respiratory tract infections, sexually transmitted infections such as lymphogranuloma venereum and nongonococcal urethritis, plague, cholera, brucellosis, tularemia, and others caused by susceptible organisms. MINOCIN Intravenous is used when oral therapy is not adequate or tolerated.

Extended-release oral minocycline tablets are indicated specifically for inflammatory lesions of moderate to severe acne vulgaris in patients 12 years and older — not for treating infections. AMZEEQ (topical foam) treats inflammatory lesions of moderate to severe acne vulgaris in patients 9 years and older. ZILXI (topical foam) and EMROSI (oral capsule) are indicated for inflammatory lesions of rosacea in adults. ARESTIN (oral powder placed by a dental professional) is used alongside scaling and root planing to reduce pocket depth in adult periodontitis.

See full Minocycline drug information
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
326Moderate
0Minor
2,503No known interaction
326 Moderate 2,503 No interaction
Moderate

326 interactions

Showing 60 of 326 moderate interactions — see all 326 on the Blue-green Algae page.

No interaction 2,503 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 2,503 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 Minocycline, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

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

Keep exploring
Blue-green Algae monograph › Uses, safety, and every drug interaction in one place Minocycline supplement interactions › Every supplement checked against Minocycline, ranked by severity Minocycline drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Blue-green Algae and Minocycline Together: Common Questions

Can you take Blue-green Algae with Minocycline?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Blue-green Algae and Minocycline interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Minocycline and Blue-green Algae?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.