Drug & supplement interaction

Blue-green Algae + abatacept

abatacept brand name: Orencia.

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

Blue-green Algae has a moderate interaction with abatacept. Theoretically, concurrent use of blue-green algae might interfere with immunosuppressive therapy.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Blue-green Algae and abatacept

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

Moderate

IMMUNOSUPPRESSANTS

Why this applies to abatacept

abatacept falls under IMMUNOSUPPRESSANTS — the group Blue-green Algae interacts with.

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

Interaction 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.

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

Here's the thing about Orencia (abatacept): its whole job is to calm down an overactive immune system so your joints stop attacking themselves. Blue-green algae, on the other hand, are thought to do the opposite, gently revving the immune system up. So the worry is that the algae could push against what your medication is trying to accomplish, possibly leaving your rheumatoid arthritis less controlled, with more joint pain, swelling, or stiffness creeping back.

I want to be honest about how soft this evidence is. This is a theoretical concern based only on lab and animal studies, not real-world reports in people. It may never amount to anything noticeable. Still, since you're relying on Orencia to keep your immune system in check, I'd run any blue-green algae product by your doctor or pharmacist before starting it.

Contact Dr. Brian directly if you have additional questions on this interaction
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. 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

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 abatacept 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. abatacept)
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.

Everything else you take

See Every Supplement That Interacts With abatacept

This page covers Blue-green Algae only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the abatacept page lists 53 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Active Hexose Correlated Compound (ahcc) (moderate), Alfalfa (moderate), American Ginseng (moderate), Andrographis (moderate) and Ashwagandha (moderate).

By severity: 52 moderate · 1 minor.

From our pharmacist’s overview on the abatacept page

“Abatacept (Orencia) treats rheumatoid arthritis and related conditions by dialing down immune activity, so the supplements that matter here are the ones pulling in the opposite direction. All 53 ingredients on this list share that single theme: herbs and mushrooms with immune-stimulating properties, echinacea, ashwagandha, and astragal…”

Reviewed by 2 · Jul 18, 2026

Open the abatacept 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 abatacept 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 abatacept 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%

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

29 days ago today
Medication abatacept
Steady interest

#2,212 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 Abatacept Injection

What Is Abatacept Injection Used For?

Brand name: Orencia

Orencia is approved for adults with moderately to severely active rheumatoid arthritis (RA) and adults and children 2 years and older with active psoriatic arthritis (PsA) or moderately to severely active polyarticular juvenile idiopathic arthritis (pJIA) — a type of arthritis that affects multiple joints in children.

Orencia is also used, alongside two other medicines (a calcineurin inhibitor and methotrexate), to prevent acute graft versus host disease (aGVHD) — a serious immune reaction — in adults and children 2 and older who receive a stem cell transplant from an unrelated donor.

See full Abatacept Injection 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 abatacept, 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 abatacept supplement interactions › Every supplement checked against abatacept, ranked by severity Abatacept Injection 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 abatacept Together: Common Questions

Can you take Blue-green Algae with abatacept?
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 abatacept 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 abatacept 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.