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Horny Goat Weed Side Effects: Heart Risk and Cautions
Reported horny goat weed side effects include sweating at high doses, a rapid irregular heartbeat, increased energy and mood changes (MSK, Epimedium (horny goat weed)). Human safety data are case reports only (Drugs.com, Horny goat weed). Memorial Sloan Kettering says not to take it with heart disease. Stallion Power lists it last, at most 9.1 mg per gummy by label arithmetic.
Written by the Stallion Power label deskUpdated · 4 min read
What side effects are reported?
Safety data on horny goat weed (Epimedium) are thin. What exists is mostly case reports, and the main worry is the heart.
| Effect or caution | What the source says |
|---|---|
| Sweating, feeling hot | At high doses (MSK, Epimedium (horny goat weed)) (Drugs.com, Horny goat weed) |
| Rapid irregular heartbeat | Listed as an adverse reaction (MSK, Epimedium (horny goat weed)) |
| Increased energy, mood changes | Listed as adverse reactions (MSK, Epimedium (horny goat weed)) |
| Stimulatory effect | High doses may cause it (Drugs.com, Horny goat weed) |
| Rash | One vasculitis-like rash after ginkgo plus horny goat weed; the cause cannot be pinned on horny goat weed alone (MSK, Epimedium (horny goat weed)) (Drugs.com, Horny goat weed) |
We looked for a complete list, including reports of dizziness, dry mouth and nosebleed. We could not open a source that lists them, so we do not state them as fact.
Why the heart gets the warning
Two sources describe the same kind of case. A 66-year-old man with congestive heart failure developed shortness of breath, chest pain, a new arrhythmia and hypomania after two weeks of daily use (MSK, Epimedium (horny goat weed)). Drugs.com describes a rapid irregular heartbeat and hypomania with agitation in an elderly patient with significant cardiac history after 2 weeks (Drugs.com, Horny goat weed).
Memorial Sloan Kettering says not to take it if you have heart disease (MSK, Epimedium (horny goat weed)). These are individual cases, not a measured rate, so the true risk is unknown. That is the point: the safety evaluations are lacking, and no safe dose has been set (MSK, Epimedium (horny goat weed)).
Chest pain, fainting, a very fast or irregular heartbeat, or sudden vision or hearing loss needs emergency care. An erection that lasts more than four hours does too.
Who should avoid it?
- Heart disease or arrhythmia: do not take it, per Memorial Sloan Kettering (MSK, Epimedium (horny goat weed)).
- Pregnant or nursing: avoid it (Drugs.com, Horny goat weed).
- Hormone-sensitive cancers: icariin may have estrogenic effects, so be cautious (MSK, Epimedium (horny goat weed)).
- Aromatase inhibitor users: a possible effect on how the drug works, with unknown clinical relevance (MSK, Epimedium (horny goat weed)).
- Thyroid problems: long-term use lowered thyroid activity in animal studies (Drugs.com, Horny goat weed).
Drugs.com says no interactions are well documented, which reflects a lack of information (Drugs.com, Horny goat weed). Keep taking prescribed medicine and tell your pharmacist about every supplement.
Stallion Power: from $49 a bottle30 gummies a bottle · 2, 3 or 6 bottles · free shipping on 3 or 6 · 60-day guarantee
See packsWhat does that mean for a gummy?
The Stallion Power label lists Horny Goat Weed Extract ninth in its blend and prints no amount. Blend lines go in descending order by weight (21 CFR 101.36, Supplement Facts), so ninth place is the lightest. The plain ceiling is 82 divided by 9, or 9.1 mg. With caffeine printed at 5 mg in fifth place, the tighter ceiling is 5 mg.
Nothing we read says that amount is unsafe, and nothing says it is safe. It is arithmetic on a printed label, not a lab result, and a real gummy can hold less. Drugs.com does not say it is unsafe at label doses (Drugs.com, Horny goat weed).
Full details are on the horny goat weed page, and the blend as a whole is covered in side effects.
A sensible next step
If you have any heart condition, ask your doctor before trying any product that lists this herb. Stop use and call your doctor if a reaction appears, as the label says.
Who wrote this01
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, FTC, NIDDK, AHA and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is run by Gostallionpower, a Stallion Power U.S. merchant desk, not by the manufacturer or the distributor named on the label. We earn money when you buy through our order links.
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