Drug & supplement interaction

Red Clover + Etravirine

Etravirine brand name: Intelence.

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

Etravirine falls into 3 drug categories that Red Clover can interact with; the most serious is rated minor. Theoretically, red clover might increase the levels and clinical effects of drugs metabolized by CYP2C19.

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

Red Clover and Etravirine

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

Why Are There 3 Interactions?

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

Minor

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

1 of 3

Why this applies to Etravirine

Etravirine falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Red Clover interacts with.

Theoretically, red clover might increase the levels and clinical effects of drugs metabolized by CYP2C19.
In vitro evidence suggests that red clover weakly inhibits CYP2C19. This interaction has not been reported in humans.
Severity Minor 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 gist for etravirine (Intelence): your body partly clears it using a liver enzyme called CYP2C19. In lab dishes, red clover appears to weakly slow that same enzyme down. If that carried over into real life, etravirine could build up a bit, which in theory might mean more of its usual side effects like rash, nausea, or headache.

The honest part: this is only a theoretical concern from test-tube work, and it has never actually been reported in people. It's rated minor and unlikely. Etravirine is an active drug (not a prodrug), so the direction would be slightly higher levels, not weaker effect. Still, because HIV treatment is something you don't want to disrupt, run any new supplement past your pharmacist or HIV provider first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

2 of 3

Etravirine also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, red clover might increase levels of drugs metabolized by CYP2C9; however, a small clinical study found no effect.
In vitro evidence suggests that red clover might inhibit CYP2C9. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of tolbutamide, a CYP2C9 probe substrate.
Severity Minor 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 short version: this is a very minor, mostly theoretical concern. Etravirine is partly handled by a liver enzyme called CYP2C9, and lab (test tube) studies hint that red clover's plant estrogens might slow that enzyme down. If that happened, etravirine could build up a little, which in theory might mean more of its usual side effects, like rash, nausea, or headache.

But here's the reassuring part: a real human study using standardized red clover did not change levels of a drug that depends on that same enzyme. So in everyday life, this combo is unlikely to cause trouble. Etravirine is not a prodrug, so it doesn't get flipped the other way. Since keeping HIV controlled matters, just let your pharmacist or doctor know before adding red clover.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Chen L, Choi J, Leonard SW, et al. No Clinically Relevant Pharmacokinetic Interactions of a Red Clover Dietary Supplement with Cytochrome P450 Enzymes in Women. J Agric Food Chem. 2020;68(47):13929-13939. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

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

Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
In vitro evidence shows that red clover might inhibit CYP3A4 isoenzymes. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of alprazolam, a CYP3A4 probe substrate.
Severity Minor Likelihood Unlikely Evidence B

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 short version: your body uses an enzyme called CYP3A4 to help process etravirine. In a test tube, red clover looked like it might slow that enzyme down a little, which in theory could let etravirine build up and cause more of its usual side effects, like nausea, headache, or skin rash. So on paper, this is worth a mention.

The good news is that the real-world evidence is reassuring. When researchers gave people standardized red clover and checked a similar CYP3A4 medication, they saw no meaningful change. Etravirine is not a prodrug, so it doesn't flip the direction here. Since keeping HIV controlled matters a lot, just let your pharmacist or doctor know before adding red clover.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  2. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  3. Chen L, Choi J, Leonard SW, et al. No Clinically Relevant Pharmacokinetic Interactions of a Red Clover Dietary Supplement with Cytochrome P450 Enzymes in Women. J Agric Food Chem. 2020;68(47):13929-13939. 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

Red Clover Also Interacts With Other Medications

Red Clover has 44 moderate, 822 minor known drug interactions in our database — the Etravirine one above is among them. If you take anything else, check it against the full list below.

Moderate 44 Minor 822 No known interaction 1,964 (incl. Etravirine)
Taking anything else?

Check Another of Your Medications Against Red Clover

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

Everything else you take

See Every Supplement That Interacts With Etravirine

This page covers Red Clover only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Etravirine page lists 169 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 · 127 moderate · 39 minor.

From our pharmacist’s overview on the Etravirine page

“For someone taking etravirine (Intelence), an HIV medicine often used when the virus has already resisted other drugs, keeping a steady blood level is the whole point, and this list of 169 supplements and herbs deserves genuine care. The three major-rated entries come first: St.”

Reviewed by 2 · Jul 18, 2026

Open the Etravirine interaction page

One more smart check

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

We hold 1,480 real supplement products containing Red Clover, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Red Clover. Your product may carry other ingredients that interact with Etravirine too, on top of Red Clover — 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 Red Clover and Etravirine 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 Red Clover
Top 25%

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

29 days ago today
Medication Etravirine
Steady interest

#2,316 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 Red Clover

What is Red Clover?

Red Clover
  • Menopause symptoms (hot flashes)
  • High cholesterol
  • Bone health/osteoporosis
  • Skin and hair concerns
  • Women's health

Red clover is a plant rich in isoflavones (plant compounds with weak estrogen-like activity) that is most often used for menopause symptoms like hot flashes. The evidence is mixed and generally weak, with some studies showing modest benefit and others showing none. Because of its hormone-like effects, it's not for everyone—talk with your pharmacist or doctor before trying it, especially if you have a hormone-sensitive condition.

Read the full Red Clover monograph & all interactions
Medication

About Etravirine

What Is Etravirine Used For?

Brand name: Intelence

Etravirine (brand name Intelence) is used to treat HIV-1 infection in people who have already received other antiretroviral (HIV) treatments — meaning it is meant for patients whose HIV has had a chance to develop resistance to earlier therapies. It is always used as part of a combination regimen with other HIV medications, never on its own.

Both the brand Intelence and generic etravirine tablets are approved for adults and for children ages 2 to under 18 who weigh at least 10 kg (about 22 pounds) and who have already been treated with other HIV drugs.

See full Etravirine drug information
Keep checking

Other Drugs & Red Clover

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

0Major
44Moderate
822Minor
1,963No known interaction
44 Moderate 822 Minor 1,963 No interaction
Moderate

44 interactions

Minor

822 interactions

Showing 60 of 822 minor interactions — see all 822 on the Red Clover page.

No interaction 1,963 drugs checked — show the list

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

Showing the 60 most looked-up of 1,963 medications checked with no known interaction — see the full Red Clover list.

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

Can you take Red Clover with Etravirine?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Red Clover and Etravirine?
Etravirine belongs to more than one drug category, and Red Clover 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 Red Clover and Etravirine interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Etravirine and Red Clover?

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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.