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Dietary supplement

Horny Goat Weed Ingredients & Drug Interactions

by GNC Men's

Horny Goat Weed label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Horny Goat Weed against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Horny Goat Weed is a dietary supplement by GNC Men's with 2 active ingredients. Its ingredients are commonly taken for low libido and sexual function, energy and stamina, menopause symptoms.Based on those ingredients, 963 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Horny Goat Weed extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Horny Goat Weed by GNC Men's

Ask about any prescription or over-the-counter medication and we check it for interactions with Horny Goat Weed by GNC Men's — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Horny Goat Weed by GNC Men's

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Aug 6, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

GNC Men's Horny Goat Weed contains two active ingredients. Maca root extract and horny goat weed extract are the plants in the capsule.

The product also contains inactive ingredients — gelatin, cellulose, magnesium stearate, calcium silicate, and silicon dioxide — which are fillers and binders that hold the capsule together.

Does it work?

Insufficient evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: support sexual health and function.
  • We looked for evidence on: Erectile dysfunction (ED), Sexual desire, Sexual dysfunction, Antidepressant-induced sexual dysfunction, Age-related testosterone deficiency, Male infertility — and 3 related terms.
  • The closest evidence on file: Maca is rated "Insufficient Reliable Evidence To Rate" for Antidepressant-induced sexual dysfunction (Natural Medicines).
  • Also on file: Maca is rated "Insufficient Reliable Evidence To Rate" for Sexual desire, Age-related testosterone deficiency, Male infertility.
  • Also on file: Horny Goat Weed is rated "Insufficient Reliable Evidence To Rate" for Sexual dysfunction, Erectile dysfunction (ED), Male infertility.

The evidence for what these ingredients actually do isn't established in the data we hold. Maca root extract is used for conditions ranging from amenorrhea (stopped periods) to sexual dysfunction and bone health, but the research is insufficient to rate how well it works for any of them.

Horny goat weed extract has the same story — it's studied for sexual dysfunction, heart disease, and bronchitis, but we don't have reliable evidence supporting its effectiveness for these uses either.

The evidence, ingredient by ingredient Maca Horny Goat Weed

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Maca root extract is generally well tolerated as a food, but long-term safety as a supplement hasn't been well studied. Horny goat weed seems well tolerated in the short term, but human safety data is limited and product quality varies.

The most common side effects from horny goat weed are dizziness, dry mouth, nosebleed, thirst, and vomiting. One case reported a heart rhythm problem (tachyarrhythmia) after two weeks of use in a man with heart disease, though it's unclear if the product contained only horny goat weed or a mix of ingredients, and causality couldn't be proven.

With long-term use, vomiting, dry mouth, thirst, and nosebleed have been reported. Maca's adverse effects include stomach pain if the fresh, uncooked form is consumed.

During pregnancy, the safety data advises against maca root extract. Horny goat weed is rated possibly unsafe in pregnancy.

There isn't enough data on either ingredient during breastfeeding — talk with your doctor or pharmacist for personalized guidance if you're nursing.

Side effects, ingredient by ingredient Maca Horny Goat Weed

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 2 matched ingredients can interact with medications — Horny Goat Weed.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 964 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check with your doctor or pharmacist if you take blood thinners or antiplatelet drugs (like warfarin or aspirin). Also confirm if you're on antihypertensive drugs, estrogen-containing medications, or drugs that depend on your liver's CYP1A2, CYP2B6, or CYP3A4 systems to break them down — the extract may increase their effects or side effects.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with insufficient evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product is marketed for men's sexual health, but neither ingredient has reliable evidence supporting its effectiveness for that or other uses. If you take blood thinners, blood pressure medications, estrogen, or drugs your liver metabolizes, you'll want to check those medications against our interaction tool or run them by your doctor or pharmacist before taking this.

Because of drug interaction risks and limited safety data, especially long-term, discuss it with your own healthcare provider first.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 25, 2018.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Horny Goat Weed, straight from the product label.

Brand GNC Men's
Barcode (UPC) 048107173432
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Jan 25, 2018
DSLD ID 82383
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult Male (18-50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Horny Goat Weed by GNC Men's, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
60
UPC/BARCODE
048107173432
IngredientAmount% DV
Maca root extract250 mg--
Horny Goat Weed extract600 mg--

Other ingredients: Gelatin, Cellulose, Magnesium Stearate, Calcium Silicate, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Actual size

Traditionally used to support sexual health

Conforms to USP <2091> for weight. Meets USP <2040> disintegration.

FDA Statement of Identity

Dietary Supplement

Formula

600 mg horny goat weed 250 mg maca extract

General

CODE 066322 GSG

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take two capsule daily. For best results, take before activity.

Precautions

Warning: Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition.

Discontinue use two weeks prior to surgery.

Keep out of reach of children.

Formulation

No sugar, no artificial colors, no artificial flavors, sodium free, no wheat, gluten free, no soy, no dairy, yeast free.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Horny Goat Weed by GNC Men's label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Horny Goat Weed label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Horny Goat Weed by GNC Men's

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Maca root extract

No known
interactions
250 mg per serving

Maca is a nutrient-rich Andean root often used for energy, libido, and menopause symptoms. Early studies suggest it may modestly help sexual desire an...

Maca root extract monograph & interactions

Horny Goat Weed extract

Interacts with
963 drugs
600 mg per serving

Horny goat weed (Epimedium) is a traditional Chinese herb most often marketed for low libido and erectile problems, but solid human evidence for these...

Horny Goat Weed extract monograph & interactions

Other (inactive) ingredients: Gelatin, Cellulose, Magnesium Stearate, Calcium Silicate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Horny Goat Weed by GNC Men's Drug Interactions

Want to check YOUR meds against Horny Goat Weed?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
963Drugs
963 Moderate

Ingredients driving the most interactions

Horny Goat Weed extract 963

Individual Drug Interactions

The ingredients in Horny Goat Weed interact with 963 drugs. Click any drug to see the details.

1 of the 2 ingredients in Horny Goat Weed interact with drugs. Each result below shows which ingredient is responsible. Horny Goat Weed extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Horny Goat Weed with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Horny Goat Weed extract6 drug types · 963 drugs

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.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, horny goat weed might increase the risk of hypotension.
Laboratory research suggests that horny goat weed might have hypotensive effects. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

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.

Likelihood Possible Evidence D
Cytochrome P450 2B6 (Cyp2B6) Substrates

Theoretically, horny goat weed might increase the effects and side effects of CYP2B6 substrates.
In vitro, horny goat weed leaf extract inhibits CYP2B6. This effect has not been reported in humans.

Likelihood Possible Evidence D
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.

Likelihood Possible Evidence D
Estrogens

Theoretically, concomitant use of horny goat weed with estrogens might increase their therapeutic and adverse effects.
In vitro evidence suggests that horny goat weed has estrogenic activity. In clinical research, horny goat weed has been shown to increase blood levels of estrogen in some females.

Likelihood Possible Evidence D
Horny Goat Weed extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Horny Goat Weed, from the product label.

GNC Men's

See all GNC Men's products
Name
General Nutrition Corporation
City
Pittsburgh
State
PA
ZipCode
15222
Phone Number
1-888-462-2548
Web Address
gnc.com
Pharmacist Counseling Corner

Horny Goat Weed by GNC Men's: Common Questions

Does Horny Goat Weed by GNC Men's interact with any medications?
Yes. Based on its ingredients, Horny Goat Weed has a known interaction with 963 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Horny Goat Weed contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this actually help with sexual function?
We don't have reliable evidence supporting that either ingredient works for sexual dysfunction. The research is insufficient to rate how well horny goat weed or maca root extract do what the label suggests.
Can I take this if I'm pregnant or breastfeeding?
No, not during pregnancy — maca is not recommended, and horny goat weed is rated possibly unsafe. For breastfeeding, there isn't enough data to know either way, so talk with your doctor or pharmacist about what's right for you.
What side effects should I watch for?
The most common ones are dizziness, dry mouth, nosebleed, thirst, and vomiting — especially with longer use. Maca may cause stomach pain. One case reported a heart rhythm problem, though causality wasn't clear.
Is maca root safe?
It's generally well tolerated as a food, but long-term safety as a supplement hasn't been well studied, so there's a gap in what we know about extended use.
Does this product have fillers or additives?
Yes, the capsule contains gelatin, cellulose, magnesium stearate, calcium silicate, and silicon dioxide as inactive ingredients to hold the capsule together.

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

Not sure if Horny Goat Weed is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Horny Goat Weed label
Go deeper

The Full Monographs Behind Horny Goat Weed’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Maca

Maca is a nutrient-rich Andean root often used for energy, libido, and menopause symptoms. Early studies suggest it may modestly help sexual desire and some menopause symptoms, but the evide...

Read the full Maca monograph → Herb & supplement monograph

Horny Goat Weed

Interacts with 963 drugs

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 s...

Read the full Horny Goat Weed monograph →
Sources

Sources & How We Checked

Horny Goat Weed's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 12 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Maca 1 reference
  1. Valerio, L. G., Jr. and Gonzales, G. F. Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii) : a critical synopsis. Toxicol.Rev 2005;24(1):11-35. PubMed

See these in context on the Maca monograph →

Horny Goat Weed 11 references
  1. Cirigliano MD, Szapary PO. Horny goat weed for erectile dysfunction. Alt Med Alert 2001;4:19-22.
  2. Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004;45:536-7. PubMed
  3. De Naeyer A, Pocock V, Milligan S, De Keukeleire D. Estrogenic activity of a polyphenolic extract of the leaves of Epimedium brevicornum. Fitoterapia 2005;76:35-40. PubMed
  4. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. PubMed
  5. Yap SP, Shen P, Li J, et al. Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium. J Ethnopharmacol 2007;113:218-24. PubMed
  6. Yan, F. F., Liu, Y., Liu, Y. F., and Zhao, Y. X. Herba Epimedii water extract elevates estrogen level and improves lipid metabolism in postmenopausal women. Phytother.Res. 2008;22(9):1224-1228. PubMed
  7. Ramanathan VS, Mitropoulos E, Shlopov B, et al. An Enzyte'ing' case of acute hepatitis. J Clin Gastroenterol 2011;45(9):834-5. PubMed
  8. 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.
  9. 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
  10. Tan K, Yang W, Pang L, Hou F. Differences in clinical characteristics among 726 patients with Chinese herbal medicine- or Western medicine-induced liver injury. Medicine (Baltimore) 2022;101(32):e29909. PubMed
  11. 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

See these in context on the Horny Goat Weed monograph →

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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