Drug & supplement interaction

Horny Goat Weed + Clopidogrel

Clopidogrel brand name: Plavix.

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

Clopidogrel falls into 3 drug categories that Horny Goat Weed can interact with; the most serious is rated moderate. Theoretically, horny goat weed might increase the effects and side effects of CYP1A2 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Horny Goat Weed and Clopidogrel

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Horny Goat Weed interacts with whole categories of medication. Clopidogrel falls into 3 of those categories, so it can interact with Horny Goat Weed in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Clopidogrel

Clopidogrel falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Horny Goat Weed interacts with.

Theoretically, horny goat weed might increase the effects and side effects of CYP1A2 substrates.
In vitro, horny goat weed leaf extract inhibits CYP1A2. This effect has not been reported in humans.
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. Lab studies suggest horny goat weed may slow down a liver enzyme called CYP1A2. The catch is that clopidogrel (Plavix) doesn't really lean on CYP1A2 to do its job. Plavix is actually a prodrug, meaning it's inactive until your body switches it on, mostly through a different enzyme called CYP2C19. So this particular interaction doesn't line up neatly with how Plavix works.

On top of that, this concern comes only from test-tube research, not from people, so it's very theoretical. I wouldn't lose sleep over it, but since Plavix is a serious blood thinner protecting your heart and stents, please run any new supplement past your pharmacist or doctor first before adding it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zhong Q, Shi Z, Zhang L, et al. The potential of Epimedium koreanum Nakai for herb-drug interaction. J Pharm Pharmacol 2017;69(10):1398-408. doi: 10.1111/jphp.12773.
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 3

Clopidogrel also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Theoretically, horny goat weed might increase the risk of bleeding.
In vitro research and animal research shows that horny goat weed can inhibit platelet aggregation and thrombus formation. This effect has not been reported in humans.
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 simple version: Plavix (clopidogrel) keeps your platelets from clumping together so you don't form dangerous clots. Horny goat weed, in lab dishes and animal studies, seems to do a little of the same thing, meaning it may also make platelets less sticky. Stack the two and the worry is a bit too much of a good thing, which can show up as easier bruising, nosebleeds, bleeding gums, or cuts that are slow to stop.

The honest part: this has only been seen in test tubes and animals, never confirmed in people, so it's more of a theoretical caution than a proven problem. Still, since you're on Plavix for serious heart or stroke protection, please run any horny goat weed product by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Irfan M, Kwon TH, Lee DH, et al. Antiplatelet and Antithrombotic Effects of Epimedium koreanum Nakai. Evid Based Complement Alternat Med. Apr 2021;2021:7071987. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Clopidogrel also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, horny goat weed might increase the effects and side effects of CYP3A4 substrates.
In vitro, horny goat weed extract inhibits CYP3A4 and suppresses CYP3A4 mRNA expression. This effect has not been reported in humans.
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 wrinkle with Plavix (clopidogrel): it's a prodrug, meaning it has to be switched on by your liver enzymes before it can thin your blood and protect your stents or arteries. CYP3A4 is one of the enzymes that helps activate it. In lab dishes, horny goat weed appears to block CYP3A4, and if that happened in your body, it could mean less of the drug gets turned into its active form, so you might get weaker clot protection.

Now, the honest part: this is only test-tube data and has never been shown in real people, so it's theoretical. Still, clopidogrel is too important to gamble with. Please check with your pharmacist or doctor before adding this herb, and don't change your Plavix on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li K, Yu XH, Maskey AR, et al. Cytochrome P450 3A4 suppression by epimedium and active compound kaempferol leads to synergistic anti-inflammatory effect with corticosteroid. Front Pharmacol 2023;13:1042756. 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

Horny Goat Weed Also Interacts With Other Medications

Horny Goat Weed has 962 moderate known drug interactions in our database — the Clopidogrel one above is among them. If you take anything else, check it against the full list below.

Moderate 962 No known interaction 1,868 (incl. Clopidogrel)
Taking anything else?

Check Another of Your Medications Against Horny Goat Weed

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

From our Q&A

Questions About Horny Goat Weed or Clopidogrel

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Horny Goat Weed or Clopidogrel, 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 Clopidogrel

This page covers Horny Goat Weed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clopidogrel page lists 309 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Grapefruit (major), Piracetam (major) and St. John's Wort (major).

By severity: 5 major · 258 moderate · 46 minor.

From our pharmacist’s overview on the Clopidogrel page

“Clopidogrel (Plavix) keeps platelets from sticking together after a stent, heart attack, or stroke, which makes this a list to take carefully. Of the 309 supplements and herbs on file, 202 carry blood-thinning or antiplatelet activity of their own and can stack bleeding risk on top of the drug's, while most of the rest change how the l…”

Reviewed by 2 · Jul 18, 2026

Open the Clopidogrel interaction page

One more smart check

Taking Horny Goat Weed as Part of a Dietary Supplement Product? Check It for Interactions

We hold 183 real supplement products containing Horny Goat Weed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Horny Goat Weed. Your product may carry other ingredients that interact with Clopidogrel too, on top of Horny Goat Weed — 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 Horny Goat Weed and Clopidogrel 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 Horny Goat Weed
Top 25%

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

29 days ago today
Medication Clopidogrel
Top 1%

#12 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 Horny Goat Weed

What is Horny Goat Weed?

Horny Goat Weed
  • Erectile dysfunction
  • Low libido
  • Fatigue and low energy
  • Bone health
  • Joint and menopausal symptoms
  • General 'vitality' or performance

Horny goat weed (Epimedium) is a traditional Chinese herb most often marketed for low libido and erectile problems, but solid human evidence for these uses is lacking. While short-term use seems generally tolerated by some people, quality and safety are not well studied, so talk to your pharmacist or doctor before trying it—especially if you have heart problems or take other medicines.

Read the full Horny Goat Weed monograph & all interactions
Medication

About Clopidogrel

What Is Clopidogrel Used For?

Brand name: Plavix

Clopidogrel tablets are used to reduce the risk of heart attack and stroke in people with acute coronary syndrome (ACS) — including unstable angina and non-ST-elevation or ST-elevation heart attacks — and in people with a history of recent heart attack, recent stroke, or established peripheral arterial disease. For ACS, it is typically given alongside aspirin.

It works by preventing platelets (blood cells that trigger clotting) from clumping together, which helps keep arteries open and lowers the chance of a dangerous clot forming.

See full Clopidogrel drug information
Keep checking

Other Drugs & Horny Goat Weed

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

0Major
962Moderate
0Minor
1,867No known interaction
962 Moderate 1,867 No interaction
Moderate

962 interactions

Showing 60 of 962 moderate interactions — see all 962 on the Horny Goat Weed page.

No interaction 1,867 drugs checked — show the list

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

Showing the 60 most looked-up of 1,867 medications checked with no known interaction — see the full Horny Goat Weed list.

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

Can you take Horny Goat Weed with Clopidogrel?
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.
Why are there 3 interactions listed for Horny Goat Weed and Clopidogrel?
Clopidogrel belongs to more than one drug category, and Horny Goat Weed interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Horny Goat Weed and Clopidogrel 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 Clopidogrel and Horny Goat Weed?

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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.