Drug & supplement interaction

Goldthread + Flutamide

Flutamide brand names: Eulexin, Euflex.

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

Goldthread has a moderate interaction with Flutamide. There's very preliminary evidence that berberine, a constituent of goldthread, might inhibit cytochrome P450 3A4 (CYP3A4) enzyme.

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

Goldthread and Flutamide

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Flutamide

Flutamide falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Goldthread interacts with.

There's very preliminary evidence that berberine, a constituent of goldthread, might inhibit cytochrome P450 3A4 (CYP3A4) enzyme. So far, this interaction has not been reported in humans. However, watch for an increase in the levels of drugs metabolized by CYP3A4 in patients taking goldthread. Some drugs metabolized by CYP3A4 include lovastatin (Mevacor), clarithromycin (Biaxin), indinavir (Crixivan), sildenafil (Viagra), triazolam (Halcion), and numerous others. Use goldthread cautiously or avoid in patients taking these drugs.
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 gist for flutamide. Your liver uses an enzyme called CYP3A4 to help process this medicine. Goldthread contains berberine, and in early lab work berberine looks like it might slow that enzyme down a bit. If it does, flutamide could clear from your body a little more slowly and build up, which in theory might raise the chance of side effects like nausea, diarrhea, or strain on the liver.

I'll be honest with you though, this is theoretical. It comes from lab studies and hasn't actually shown up in real patients, so it may never matter for you. Still, since flutamide and liver health both deserve respect, please check with your oncology team or pharmacist before adding goldthread.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72. 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

Goldthread Also Interacts With Other Medications

Goldthread has 642 moderate known drug interactions in our database — the Flutamide one above is one of them. If you take anything else, check it against the full list below.

Moderate 642 No known interaction 2,188 (incl. Flutamide)
Taking anything else?

Check Another of Your Medications Against Goldthread

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

Everything else you take

See Every Supplement That Interacts With Flutamide

This page covers Goldthread only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Flutamide page lists 189 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 143 moderate · 43 minor.

From our pharmacist’s overview on the Flutamide page

“A man taking flutamide (Eulexin) to block testosterone during prostate cancer treatment cannot afford big swings in the drug's level, and most of the 189 supplements on this page are capable of causing exactly that. The bulk of them work through the liver enzyme CYP3A4, which breaks flutamide down.”

Reviewed by 2 · Jul 18, 2026

Open the Flutamide interaction page

One more smart check

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

We hold 25 real supplement products containing Goldthread, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Goldthread. Your product may carry other ingredients that interact with Flutamide too, on top of Goldthread — 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 Goldthread and Flutamide 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 Goldthread
Top 25%

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

29 days ago today
Medication Flutamide
Steady interest

#1,585 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 Goldthread

What is Goldthread?

Goldthread
  • Digestive upset and diarrhea
  • Mouth sores and sore throat
  • Inflammation
  • Antimicrobial (fighting germs)
  • Blood sugar support
  • Skin and eye complaints

Goldthread is a traditional Chinese and East Asian herb whose root is rich in berberine, a compound being studied for blood sugar, cholesterol, and antimicrobial effects. Strong human evidence for goldthread itself is limited, and it should be avoided in pregnancy and breastfeeding. Talk with your pharmacist or doctor before using it, especially if you take other medicines.

Read the full Goldthread monograph & all interactions
Medication

About Flutamide

What Is Flutamide Used For?

Brand names: Eulexin, Euflex

Eulexin (flutamide) capsules are used to treat prostate cancer in men. They are always used together with an LHRH agonist (a hormone-lowering injection), never alone.

Eulexin is indicated for two stages of prostate cancer: locally confined Stage B2-C prostate cancer (used alongside goserelin acetate and radiation therapy, starting eight weeks before radiation begins) and Stage D2 metastatic prostate cancer (cancer that has spread beyond the prostate, taken with an LHRH agonist until the disease progresses).

See full Flutamide drug information
Keep checking

Other Drugs & Goldthread

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

0Major
642Moderate
0Minor
2,187No known interaction
642 Moderate 2,187 No interaction
Moderate

642 interactions

Showing 60 of 642 moderate interactions — see all 642 on the Goldthread page.

No interaction 2,187 drugs checked — show the list

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

Showing the 60 most looked-up of 2,187 medications checked with no known interaction — see the full Goldthread list.

See the full Goldthread interactions page
See every supplement checked against Flutamide, 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
Goldthread monograph › Uses, safety, and every drug interaction in one place Flutamide supplement interactions › Every supplement checked against Flutamide, ranked by severity Flutamide 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 Goldthread and Flutamide Together: Common Questions

Can you take Goldthread with Flutamide?
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 Goldthread and Flutamide 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 Flutamide and Goldthread?

Our pharmacists answer your medication & supplement questions — free.

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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.