Drug & supplement interaction

Red Clover + Diphenhydramine Hydrochloride, Naproxen Sodium

Diphenhydramine Hydrochloride, Naproxen Sodium brand name: Aleve PM.

Minor Interaction
The bottom line Minor

Diphenhydramine Hydrochloride, Naproxen Sodium falls into 3 drug categories that Red Clover can interact with; the most serious is rated minor. Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.

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

Red Clover and Diphenhydramine Hydrochloride, Naproxen Sodium

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. Diphenhydramine Hydrochloride, Naproxen Sodium 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 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Diphenhydramine Hydrochloride, Naproxen Sodium

Diphenhydramine Hydrochloride, Naproxen Sodium falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Red Clover interacts with.

Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
In vitro evidence shows that red clover inhibits CYP1A2. 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 caffeine, a CYP1A2 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

If you take Aleve PM (which combines naproxen for pain with diphenhydramine, the sedating ingredient in many sleep aids), here's the short version on red clover. In a test tube, red clover's plant estrogens can slow down an enzyme called CYP1A2. The worry on paper is that this could let drugs cleared by that enzyme build up a bit, theoretically nudging up side effects like extra drowsiness, dry mouth, or a groggy morning feeling from the diphenhydramine.

The good news: this is theoretical, based on lab work, and a small human study found red clover did not actually change how the body handled a CYP1A2 test drug. Neither naproxen nor diphenhydramine is a prodrug, so there's no hidden flip here. I wouldn't lose sleep over it, but check with your pharmacist if you use red clover regularly.

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 2C9 (CYP2C9) SUBSTRATES

2 of 3

Diphenhydramine Hydrochloride, Naproxen Sodium 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 gist with Aleve PM, which pairs naproxen (a pain and inflammation reliever) with diphenhydramine (a sedating antihistamine). The naproxen part is partly broken down by a liver enzyme called CYP2C9. In a test-tube setting, red clover looked like it might slow that enzyme down, which could in theory let naproxen build up a bit and nudge up its usual side effects, things like stomach upset, heartburn, or a higher bleeding risk.

That said, this is very weak, lab-only evidence, and a small human study found red clover did not actually change levels of a similar CYP2C9 drug. So real-world risk looks low. If you take Aleve PM regularly or have stomach or bleeding concerns, just run it by your pharmacist first.

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

ANTICOAGULANT/ANTIPLATELET DRUGS

3 of 3

Diphenhydramine Hydrochloride, Naproxen Sodium also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Although some laboratory research suggests that red clover may have anticoagulant and antiplatelet activity, clinical research has not shown this effect.
In vitro research suggests that genistein in red clover has antiplatelet effects, and historically, red clover was thought to have anticoagulant effects due to its coumarin content. However, some experts state that this is unlikely as most natural coumarins have not been shown to have anticoagulant effects, and their content in red clover is low. Additionally, some clinical research in postmenopausal patients found no effect on coagulation or prothrombin time with the use of red clover flowering tops 378 mg daily for 12 months or red clover isoflavone (Rimostil) 50 mg daily for 2 years.
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 situation with Aleve PM, which combines naproxen (an anti-inflammatory pain reliever) and diphenhydramine (the sleep-aid antihistamine). The naproxen piece is what matters here. Naproxen can already thin the blood a little and irritate the stomach lining. The concern with red clover is that, in test-tube studies, one of its plant compounds (genistein) looked like it might affect platelets, the cells that help blood clot. Stack that on top of naproxen and, in theory, you might bruise or bleed a touch more easily.

The good news is that real human studies haven't actually shown red clover thinning the blood, even after months of use. So this is mostly a theoretical worry, not a strong one. Still, if you take Aleve PM regularly or notice easy bruising, dark stools, or stomach upset, check in with your pharmacist or doctor before adding red clover.

References
  1. Geller SE, Shulman LP, van Breemen RB, et al. Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trial. Menopause 2009;16:1156-66. PubMed
  2. Guerrero JA, Lozano ML, Castillo J, et al. Flavonoids inhibit platelet function through binding to the thromboxane A2 receptor. J Thromb Haemost 2005;3(2):369-376. PubMed
  3. Kondo K, Suzuki Y, Ikeda Y, Umemura K. Genistein, an isoflavone included in soy, inhibits thrombotic vessel occlusion in the mouse femoral artery and in vitro platelet aggregation. Eur J Pharmacol 2002;455(1):53-57. PubMed
  4. Polini N, Rauschemberger MB, Mendiberri J, et al. Effect of genistein and raloxifene on vascular dependent platelet aggregation. Mol Cell Endocrinol 2007;267(1-2):55-62. PubMed
  5. Clifton-Bligh PB, et al. Red cover isoflavones enriched with formononetin lower serum LDL cholesterol- a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr. 2015;69(1):134-142.

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, 824 minor known drug interactions in our database — the Diphenhydramine Hydrochloride, Naproxen Sodium one above is among them. If you take anything else, check it against the full list below.

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 Diphenhydramine Hydrochloride, Naproxen Sodium

This page covers Red Clover only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diphenhydramine Hydrochloride, Naproxen Sodium page lists 378 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Danshen (major).

By severity: 13 major · 320 moderate · 45 minor.

From our pharmacist’s overview on the Diphenhydramine Hydrochloride, Naproxen Sodium page

“Aleve PM combines naproxen, an NSAID, with the sedating antihistamine diphenhydramine, and its supplement list earns genuine care rather than a quick skim. Thirteen of the 378 ingredients on file rate major, and the two largest themes track the pill's two halves.”

Reviewed by 2 · Jul 18, 2026

Open the Diphenhydramine Hydrochloride, Naproxen Sodium 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 Diphenhydramine Hydrochloride, Naproxen Sodium 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 Diphenhydramine Hydrochloride, Naproxen Sodium 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%

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

29 days ago today
Medication Diphenhydramine Hydrochloride, Naproxen Sodium
Top 5%

#71 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
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
824Minor
1,961No known interaction
Moderate

44 interactions

Minor

824 interactions

Showing 60 of 824 minor interactions — see all 824 on the Red Clover page.

No interaction 1,961 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 1,961 medications checked with no known interaction — see the full Red Clover list.

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

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Pharmacist Counseling Corner

Taking Red Clover and Diphenhydramine Hydrochloride, Naproxen Sodium Together: Common Questions

Can you take Red Clover with Diphenhydramine Hydrochloride, Naproxen Sodium?
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 Diphenhydramine Hydrochloride, Naproxen Sodium?
Diphenhydramine Hydrochloride, Naproxen Sodium 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 Diphenhydramine Hydrochloride, Naproxen Sodium 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

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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.