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Horny goat weed (Epimedium)

Horny goat weed is also known as or Epimedium or barrenwort. Its botanical name is Epimedium sagittatum.

It is a herb that has been used as a traditional remedy in China for centuries. It is used by some people in the hope of helping low libido, erectile dysfunction, fatigue, pain and other conditions.

No THR

Herbal remedies in the UK are regulated by the medicines body MHRA. It runs a traditional herbal registration scheme called THR. It has not yet issued a registration for horny goat weed.

Unlike licensing for mainstream medicines, registration doesn't mean a herbal remedy has been tested and proven to actually work. It does mean the MHRA is satisfied the product is made to good quality standards with appropriate labelling and a product information leaflet. It also means the herb has been used in traditional remedies for more than 30 years.

People selling horny goat weed are not allowed to make claims about the product, such as any aphrodisiac properties.

Horny goat weed uses

Some men take horny goat weed in the belief that it’s a natural alternative to drugs for erectile dysfunction (ED). Although still very preliminary, there’s some evidence to support this. A 2008 laboratory study found that a compound in the herb blocks the effects of an enzyme that restricts blood flow to the penis. Epimedium, the plant from which horny goat weed is derived appears to act as a phosphodiesterase inhibitor, similar to some of the drugs currently prescribed for ED. The study also suggested that horny goat weed could theoretically work better - and cause fewer side-effects - than current drugs for erectile dysfunction.

Although the study was promising, it was based only on experiments in the laboratory. It’s too early to tell if horny goat weed will prove an effective and safe treatment in people.

Horny goat weed has also been studied as a treatment for other conditions, such as osteoporosis and hardening of the arteries. The results have been unclear.

Horny goat weed dosage and instructions for use

Horny goat weed is an unproven treatment, and there is no established dose.

Horny goat weed food sources

There are no natural food sources of horny goat weed.

Horny goat weed supplement information

Horny goat weed can come in many forms: powders, capsules and tinctures. As with any supplement, keep horny goat weed in a cool, dry place, away from humidity and direct sunlight.

Horny goat weed warnings

  • Side-effects. Most people seem to tolerate short-term use of horny goat weed fairly well, at least at the doses studied. It may cause upset stomach and dry mouth. In some people, horny goat weed may cause irregular heartbeat, low blood pressure, nosebleeds and mood changes. High doses have been linked to spasms and respiratory failure.
  • Risks. Horny goat weed may not be safe in high doses or as a long-term treatment. People who have health conditions - such as immune disorders, heart or lung problems, low blood pressure, bipolar disorder or thyroid problems - should not use horny goat weed without checking with their doctor.
  • Interactions. If you take any medicines or supplements regularly, talk to your doctor before you start using horny goat weed. It could interact with drugs such as blood thinners, aspirin, oral contraceptives, antidepressants, treatments for immune disorders and thyroid problems, and drugs that lower blood pressure or cholesterol.

Given the possible risks, women who are pregnant or breastfeeding and children should not take horny goat weed.

WebMD Medical Reference

Medically Reviewed by Dr Rob Hicks on June 01, 2017

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