Major interaction on record — check this product against your medications before combining. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Horny Goat Weed Ingredients & Drug Interactions

by Wonder Laboratories

Capsule Category: Botanical
Most serious interaction: Major
The interaction bottom line Most serious interaction: Major

Horny Goat Weed is a dietary supplement by Wonder Laboratories with 4 active ingredients. Its ingredients are commonly taken for erectile dysfunction, low libido, fatigue and low energy.Based on those ingredients, 1,116 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Horny Goat Weed, Mucuna pruriens. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Horny Goat Weed by Wonder Laboratories

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

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 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains 4 active ingredients. Horny Goat Weed is the main ingredient, traditionally used for sexual function and bone health, though evidence is limited.

Mucuna pruriens (cowhage) is a plant seed that naturally contains levodopa, an active compound normally used to treat Parkinson's disease—which is why it carries significant drug interaction potential. Maca Extract is included as an adaptogenic ingredient, also with limited evidence for its claimed uses.

The capsules also contain inactive ingredients: gelatin, vegetable cellulose, vegetable magnesium stearate, and silica.

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: sexual function and male vitality.
  • We looked for evidence on: Erectile dysfunction (ED), Sexual dysfunction, Sexual desire, Age-related testosterone deficiency, Male infertility, Antidepressant-induced sexual dysfunction — and 4 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 Chronic fatigue syndrome (CFS), Fatigue, Sexual desire, Age-related testosterone deficiency, and more.
  • Also on file: Horny Goat Weed is rated "Insufficient Reliable Evidence To Rate" for Sexual dysfunction.

The evidence supporting this product's uses is not established in our data. Horny Goat Weed is listed with insufficient reliable evidence for sexual dysfunction, osteoporosis, bronchitis, and heart disease.

Mucuna pruriens also has insufficient evidence for anxiety, Parkinson's disease, rheumatoid arthritis, and other conditions in the data we hold. Maca Extract similarly lacks reliable evidence for sexual function, athletic performance, osteoporosis, anemia, and amenorrhea.

If you're considering this product for a specific health goal, talk with your pharmacist about what the clinical evidence actually shows.

The evidence, ingredient by ingredient Horny Goat Weed Cowhage Maca

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Short-term use of Horny Goat Weed appears generally well tolerated, though product quality varies between manufacturers. Common side effects in short-term use include dizziness, dry mouth, nosebleed, thirst, and vomiting.

Long-term use has been linked to reports of vomiting, dry mouth, thirst, and nosebleed. One case report described a 66-year-old man with heart disease who developed an irregular heartbeat after two weeks, though it's unclear if other ingredients in his product were responsible.

Mucuna pruriens (cowhage) seems tolerated orally in the short term, but side effects can include diarrhea, flatulence, mucosal irritation, headaches, nausea, abdominal bloating, and vomiting—and in clinical studies, about 3% of people reported insomnia. Maca Extract can cause stomach pain if consumed raw or uncooked.

Because human safety data for all three checked ingredients is limited, especially long-term, use only under professional guidance. Do not use during pregnancy—Horny Goat Weed and Maca Extract lack sufficient safety data, and Mucuna pruriens should be avoided because of its dopamine-related effects.

Do not breastfeed while taking this product; Mucuna pruriens can lower prolactin and reduce milk supply, and the other ingredients also lack adequate safety data for lactation.

Side effects, ingredient by ingredient Horny Goat Weed Cowhage Maca

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 2 of the 3 matched ingredients can interact with medications — Horny Goat Weed, Cowhage.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; Parkinson's medications.
  • For scale: 1,117 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, double-check with your pharmacist if you take methyldopa or any monoamine oxidase inhibitor (MAOI)—these are Major-level interactions to avoid. Also check if you use levodopa, blood thinners, blood pressure medications, diabetes drugs, antipsychotics, tricyclic antidepressants (older-type), anesthetics, or guanethidine.

No interactions are documented for Maca Extract or Polypodium vulgare extract (which we could not check).

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. Major medication interactions have been identified, and safety information is well characterized.

This product carries real drug interaction risks, especially if you take blood pressure medications, older antidepressants, blood thinners, diabetes drugs, or antipsychotics—because of the Mucuna pruriens ingredient. The evidence for what it claims to do is not established.

If you're thinking about it, check your exact medications with the tool on this page first, then talk with your pharmacist before starting.

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

Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Dec 18, 2021.

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 Wonder Laboratories
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Dec 18, 2021
DSLD ID 261037
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Wonder Laboratories, 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
50
IngredientAmount% DV
Horny Goat Weed500 mg--
Mucuna pruriens33.4 mg--
Polypodium vulgare ext.25 mg--
Maca Extract250 mg--

Other ingredients: Gelatin, Vegetable Cellulose, Vegetable Magnesium Stearate, Silica

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.
Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take 2 capsules daily with a meal. For a more immediate response take 3 to 4 capsules 90 minutes before activity.

Precautions

Tamper Evident: Do not use this product if imprinted foil seal under cap is broken or missing.

Keep out of reach of children

Caution: If you are pregnant or nursing, consult your physician before taking this product.

Formulation

Mfg. in a FDA registered facility using Good Manufacturing Practices (GMPs)

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

Made in USA

Dynamic complex

Gluten free

Storage

Keep tightly closed. Store at room temperature: 59 degrees-86 degrees F (15 degrees to 30 degrees C).

General Statements

Reorder 5941

FDA Statement of Identity

Dietary supplement

See for yourself

Horny Goat Weed by Wonder Laboratories label

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

What’s inside

The Ingredients in Horny Goat Weed by Wonder Laboratories

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container50 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.

Horny Goat Weed

Interacts with
963 drugs
500 mg per serving Form: Icariin

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 monograph & interactions

Mucuna pruriens

Interacts with
193 drugs
33.4 mg per serving Form: L-Dopa

Cowhage (Mucuna pruriens) is a tropical legume best known as a natural source of L-dopa, the compound the body turns into dopamine. It is most studied...

Mucuna pruriens monograph & interactions

Polypodium vulgare ext.

25 mg per serving

Maca Extract

No known
interactions
250 mg per serving Form: Macamides and Macaenes

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 Extract monograph & interactions

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

Interaction report

Horny Goat Weed by Wonder Laboratories 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
1,116Drugs
17 Major 1,099 Moderate

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

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

Horny Goat Weed6 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

Mucuna pruriens8 drug types · 193 drugs

Levodopa

Concomitant use can increase the risk of levodopa-related adverse effects.
Cowhage contains levodopa. Some cowhage products have been standardized to contain 75-400 mg of levodopa per dose.

Likelihood Likely Evidence D
Methyldopa (Aldomet)

Theoretically, concomitant use of cowhage and methyldopa might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with methyldopa might cause additive hypotension. In addition, methyldopa may inhibit peripheral decarboxylation of levodopa and increase levodopa levels in the central nervous system; avoid using.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, concomitant use of cowhage and non-selective MAOIs might increase the risk of hypertensive crisis.
Cowhage contains levodopa. Use of levodopa with non-selective MAOIs might cause hypertensive crisis. However, this interaction has not been reported with MAO-B selective inhibitors such as selegiline.

Likelihood Probable Evidence D
Anesthesia

Theoretically, concomitant use of cowhage and anesthesia might increase the risk of arrhythmias.
Cowhage contains levodopa. Use of levodopa with cyclopropane or halogenated hydrocarbon anesthesia has led to arrhythmias. Other anesthetics have not been implicated. Use other anesthetics in patients taking cowhage or tell patients to stop taking cowhage at least 2 weeks before surgery.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, concomitant use of cowhage and antidiabetes drugs might increase the risk of hypoglycemia.
Animal research shows that cowhage might have hypoglycemic effects.

Likelihood Possible Evidence D
Antipsychotic Drugs

Theoretically, use of cowhage might decrease the clinical effects of antipsychotic drugs.
Cowhage contains levodopa. Use of levodopa might counteract the antidopaminergic effects of antipsychotic medications.

Likelihood Possible Evidence D
Guanethidine (Ismelin)

Theoretically, concomitant use of cowhage and guanethidine might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with guanethidine might cause additive hypotension; avoid using.

Likelihood Probable Evidence D
Tricyclic Antidepressants (Tcas)

Theoretically, use of TCAs might reduce the levels and clinical effects of cowhage.
Cowhage contains levodopa. Use of TCAs might reduce the absorption of levodopa. Some case reports describe patients that developed hypertension and dyskinesia when taking both levodopa and TCAs.

Likelihood Possible Evidence D
The maker

Brand information

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

Wonder Laboratories

See all Wonder Laboratories products
Name
Wonder Laboratories
Street Address
115 S.C.T. Ct.
City
White House
State
TN
ZipCode
37188
Pharmacist Counseling Corner

Horny Goat Weed by Wonder Laboratories: Common Questions

Does Horny Goat Weed by Wonder Laboratories interact with any medications?
Yes. Based on its ingredients, Horny Goat Weed has a known interaction with 1,116 medications, including 17 rated major. 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 4 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.
Can I take this if I'm pregnant or breastfeeding?
No. Horny Goat Weed and Maca Extract lack enough safety data in pregnancy, and Mucuna pruriens should be avoided because of its effects on dopamine and the developing baby. During breastfeeding, Mucuna pruriens can lower prolactin and reduce milk supply, and the other ingredients also haven't been studied enough. Talk with your doctor or pharmacist for personalized advice.
What are the most common side effects?
From Horny Goat Weed: dizziness, dry mouth, nosebleed, thirst, and vomiting. From Mucuna pruriens: diarrhea, flatulence, mucosal irritation, headaches, nausea, abdominal bloating, and vomiting—and about 3% of people in studies reported insomnia. From Maca Extract: stomach pain if consumed raw or uncooked.
Does this product actually work for sexual function?
The evidence isn't established in our data. Horny Goat Weed is listed with insufficient reliable evidence for sexual dysfunction, as is Mucuna pruriens. If you're considering it for that reason, talk with your pharmacist about what clinical studies actually show.
What is Mucuna pruriens and why should I care about it?
Mucuna pruriens is a plant seed that naturally contains levodopa, an active drug-like compound normally prescribed for Parkinson's disease. Because it's an active compound, it has significant interactions with many medications—especially blood pressure drugs, antidepressants, and diabetes drugs—which is why we flag it carefully.
Should I be concerned about long-term use?
Yes. Safety data for all three checked ingredients is limited, especially for long-term use. Long-term use of Horny Goat Weed has been linked to reports of vomiting, dry mouth, thirst, and nosebleed. Use only under professional guidance and only as short-term.
What does the Maca Extract do in this product?
Maca Extract is included as an adaptogenic ingredient, but the evidence for what it claims to do—such as improving sexual function, athletic performance, or bone health—is not established in our data.

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

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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
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 24 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.

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 →

Cowhage 12 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Anon. Epidemiological notes and reports: Mucuna pruriens-associated pruritus--New Jersey. MMWR Morb Mortal Wkly Rep 1985;34:732-3.
  4. HP-200 in Parkinson's Disease study group. An alternative medicine treatment for Parkinson's disease: Results of a multicenter clinical trial. J Alt Comp Med 1995;1:249-55. DOI
  5. Infante ME, Perez AM, Simao MR, et al. Outbreak of acute toxic psychosis attributed to Mucuna pruriens. Lancet 1990;336:1129. PubMed
  6. Vaidya AB, Rajagopalan TG, Mankodi NA, et al. Treatment of Parkinson's disease with the cowhage plant-Mucuna pruriens Bak. Neurol India 1978;26:171-6.
  7. Vadivel V, Janardhanan K. Nutritional and anti-nutritional composition of velvet bean: an under-utilized food legume in south India. Int J Food Sci Nutr 2000;51:279-87. PubMed
  8. Akhtar MS, Qureshi AQ, Iqbal J. Antidiabetic evaluation of Mucuna pruriens, Linn seeds. J Pak Med Assoc 1990;40:147-50.
  9. Prakash, D., Niranjan, A., and Tewari, S. K. Some nutritional properties of the seeds of three Mucuna species. Int.J.Food Sci.Nutr. 2001;52(1):79-82.
  10. Vadivel, V. and Janardhanan, K. Nutritional and antinutritional characteristics of seven South Indian wild legumes. Plant Foods Hum.Nutr 2005;60(2):69-75. PubMed
  11. Creapure (Creatine Monohydrate). Toxicological Datasheet. Degussa BioActives. Available at: https://www.fda.gov/ohrms/DOCKETS/.../95s-0316-rpt0154-54-Ref-50-vol112.pdf.
  12. Pulikkalpura H, Kurup R, Mathew PJ, Baby S. Levodopa in Mucuna pruriens and its degradation. Sci Rep 2015;5:11078. PubMed

See these in context on the Cowhage monograph →

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 →

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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