Drug & supplement interaction

Blue Cohosh + Troglitazone

Troglitazone brand name: Rezulin.

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

Blue Cohosh has a moderate interaction with Troglitazone. There is some concern that blue cohosh might increase blood glucose levels.

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

Blue Cohosh and Troglitazone

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Troglitazone

Troglitazone falls under ANTIDIABETES DRUGS — the group Blue Cohosh interacts with.

There is some concern that blue cohosh might increase blood glucose levels. Theoretically, it might decrease the effectiveness of medicines used for diabetes. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
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

Troglitazone (Rezulin) is a diabetes medicine that helps your body use insulin better and keep blood sugar in check. The worry with blue cohosh is that this herb may nudge blood sugar levels upward. If that happens, it could work against your medication and make your numbers harder to control, possibly leading to symptoms like more thirst, frequent urination, or fatigue.

I want to be honest about the strength of this concern: it's theoretical, based on how the herb behaves rather than solid human studies. Troglitazone is also no longer on the market in the US due to liver safety problems. Either way, blue cohosh has real risks of its own, so please check with your pharmacist or doctor before combining anything like this.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  2. Scott, C. C. and Chen, K. K. The pharmacological action of N-methylcytisine. The Journal of Pharmacology and Experimental Therapuetics 1943;79:334-339. DOI

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 Cohosh Also Interacts With Other Medications

Blue Cohosh has 258 moderate known drug interactions in our database — the Troglitazone one above is one of them. If you take anything else, check it against the full list below.

Moderate 258 No known interaction 2,572 (incl. Troglitazone)
Taking anything else?

Check Another of Your Medications Against Blue Cohosh

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

Everything else you take

See Every Supplement That Interacts With Troglitazone

This page covers Blue Cohosh only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Troglitazone page lists 280 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Acai (moderate).

By severity: 4 major · 239 moderate · 37 minor.

From our pharmacist’s overview on the Troglitazone page

“Most people taking troglitazone (Rezulin) are managing type 2 diabetes, and this list reflects that. The great majority of the 280 flagged ingredients act on blood sugar, most lowering it and a few raising it, so pairing them with a diabetes medication makes glucose control less predictable and can tip it too low.”

Reviewed by 2 · Jul 18, 2026

Open the Troglitazone interaction page

One more smart check

Taking Blue Cohosh as Part of a Dietary Supplement Product? Check It for Interactions

We hold 126 real supplement products containing Blue Cohosh, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Blue Cohosh. Your product may carry other ingredients that interact with Troglitazone too, on top of Blue Cohosh — 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 Cohosh and Troglitazone 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 Cohosh
Steady interest

#1,066 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Troglitazone
Steady interest

#1,874 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 Cohosh

What is Blue Cohosh?

  • Inducing labor or starting menstruation
  • Menstrual cramps and irregular periods
  • Symptoms of menopause
  • Pelvic or uterine discomfort
  • Traditional Native American remedy

Blue cohosh is a traditional herb historically used by Native Americans and midwives to bring on labor or menstruation, but it carries serious safety concerns, especially for the heart and during pregnancy. There is very little reliable human evidence that it works, and reports of harm—including serious problems in newborns—make it an herb most people should avoid without close professional supervision.

Read the full Blue Cohosh monograph & all interactions
Keep checking

Other Drugs & Blue Cohosh

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

0Major
258Moderate
0Minor
2,571No known interaction
258 Moderate 2,571 No interaction
Moderate

258 interactions

Showing 60 of 258 moderate interactions — see all 258 on the Blue Cohosh page.

No interaction 2,571 drugs checked — show the list

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

Showing the 60 most looked-up of 2,571 medications checked with no known interaction — see the full Blue Cohosh list.

See the full Blue Cohosh interactions page
See every supplement checked against Troglitazone, 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 Cohosh monograph › Uses, safety, and every drug interaction in one place Troglitazone supplement interactions › Every supplement checked against Troglitazone, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Blue Cohosh and Troglitazone Together: Common Questions

Can you take Blue Cohosh with Troglitazone?
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 Cohosh and Troglitazone 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 Troglitazone and Blue Cohosh?

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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.