Does Horny Goat Weed Boost Testosterone?

If you are looking for a natural way to boost testosterone levels then horny goat weed may have come up on your search radar.

An extract taken from an Asian plant, horny goat weed is available in supplement form and is reported to have many health benefits and is used to treat a variety of complaints including low libido and erectile dysfunction. Whilst there are limited studies as to the efficacy of this supplement, there is some evidence to support the claims.

In this article, we take a look at exactly what horny goat weed is, the claims it makes about boosting testosterone as well as any evidence to support them.

We’ll also give you some natural alternatives to horny goat weed so you can make an informed choice about which supplement to use.


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What is Horny Goat Weed?

Horny goat weed is the common and colloquial name given to epimedium, a deciduous perennial that is native to China and other parts of Asia.

There are species that grow in the Mediterranean but the majority are unique only to parts of China.

Also known as yin yang huo, bishop’s hat, fairy wings and barrenwort, horny goat weed is used as a dietary supplement and as a component in traditional Chinese medicine.

horny goat weed boost testosterone

A plant found mainly in Asia, horny goat weed has been used in traditional Chinese medicine to treat erectile dysfunction for centuries. Image via Flickr.

Nicknamed horny goat weed after indigenous sheep and goats were observed to act more ‘frisky’ after grazing on it, the supplement is regularly touted as a way to treat erectile dysfunction as well as boost testosterone levels.

Though there are many varieties of this endemic Chinese plant, the species commonly used for extracting the supplement known as Horny Goat Weed is ‘epimedium grandiflorum’. This particular species is native only to Korea, Japan and China.

The genus has pretty flowers in spring and has been cultivated for use in gardens of varying climates with some cultivars gaining merit from the Royal Horticultural Society.

As well as containing icariin (see below), horny goat weed also contains:

  • Desmethylicaritin
  • Icaritin
  • Anhydroicaritin
  • Quercitin
  • Diphylloside A and B
  • Sagittatoside B
  • Ikarioside A and B

Does it Boost Testosterone?

With a nickname like Horny Goat Weed, it is no surprise that this potent supplement should be linked with anti-impotency and libido boosting properties but what is the science behind these claims and does horny goat weed increase testosterone?

Well, epimedium contains icariin, a chemical compound that is known to have aphrodisiac properties. This same flavonoid has also been shown (in vitro) to be a weak PDE5 inhibitor. PDE5 inhibitors like Viagra and Cialis are used to treat erectile dysfunction by preventing the degradative effects of PDE5 on the smooth muscle cells lining the corpus cavernosum of the penis.  

In a study using rats that had suffered nerve crush injury to the genital area, the erectile function was improved by administering icariin. So, it can help with erectile dysfunction but what about testosterone?

treat erectile dysfunction with horny goat weed

Used to treat ED, horny goat weed can improve erectile function. Image via Flickr.

Well, in a similar study, rats that were given icariin were found to have both an increased circulation of testosterone but also improved reproductive health.

In a test conducted on castrated lab rats using a dose of 1-5mg per kg of body weight a significant improvement in erectile function was noted but had no effect on testosterone. However, in chemically castrated rats (using 200mg per kg of body weight) the effects on testosterone were much more pronounced and after just seven days, testosterone levels had tripled when compared to the control group. However, LH and FSH levels remained static.

Whilst the results of this study have led to dosages being calculated in the human population of 12.8mg per kg of body weight as being comparative, there are no clinical trials in humans to confirm whether the effects would be correlative.

What Other Health Benefits Does Horny Goat Weed Have?

In studies performed in vitro or on lab rates, icariin has been shown to improve the production of nitric oxide which is a great thing. Nitric oxide helps to improve blood flow, expanding the vessels, and delivering important oxygen to muscles to increase efficiency and endurance. Not only that but nitric oxide also plays an important part in:

  • Regulating blood pressure.
  • Reducing inflammation.
  • Improving sleep quality.
  • Improving memory.
  • Increasing strength.

As well as being a weak antioxidant, icariin has been shows to have antidepressant qualities in mice and mimics the effects of testosterone in rats.

In addition, the prenylflavonoids in horny goat weed act like phytoestrogens and can mimic estrogen reducing the negative symptoms associated with the menopause in women. This includes bone loss and low libido.

horny goat weed improve sleep quality

All round health booster? Horny goat weed can help improve the quality of your sleep. Image via Pixabay.

What are the Down Sides of Horny Goat Weed?

Well, it all sounds great so far, so, what’s the catch? Well, there are several known side effects of using this supplement, most of which are quite rare but remain a possibility. As ever with dietary supplements, care should be taken to ensure that the correct dosage is taken and that the extract is sourced from a reputable manufacturer.

Side effects include:

  • Low blood pressure.
  • Slow blood clotting.
  • Exacerbating pre-existing hormone sensitive conditions such as breast or uterine cancer.
  • Headaches
  • Dry mouth.
  • Dizziness
  • Nausea
  • Skin rashes.

Because horny goat weed might slow blood clotting it is recommended that you do not take the supplement in addition to any other drugs that have anticoagulant properties. These include, but are not limited to, aspirin, diclofenac, ibuprofen, naproxen and warfarin.

There is also a concern that because horny goat weed can decrease blood pressure that the extract is not safe to take with any other hypertensive drugs including, but not limited to, iosartan, captopril, furosemide and enalapril.

It is possible to overdose on horny goats weed which can result in severe breathing difficulties, heart arrhythmia and spasms.

What Alternatives are Available?

If you are looking for a natural way to boost testosterone levels then there are a number of products that lay similar claims to horny goats weed. Principle amongst these is tribulus terrestris.

Tribulus terrestris, also known as puncture vine, is a plant extract that claims to boost libido, increase testosterone levels as well as support healthy urinary and immune systems. The active compound in tribulus is a steroidal saponins called protodioscin which has been shown in animal studies to boost testosterone levels by as much as 52% (in primates) with limited studies showing a similar response in humans.

Happily, there are no known side effects or interactions associated with supplementing with tribulus terrestris though it is important that the source of the plant is from a reputable supplier to ensure that it has been prepared without using the aerial parts of the plant (known to cause respiratory problems).  

You can find out more by reading our guide to tribulus terrestris, here.

boost testosterone naturally

You can boost testosterone naturally with your choice from a range of supplements or make some changes to your lifestyle and diet. Image via Flickr.

Bulbine Natalensis is reported to have a positive effect on testosterone levels and is also a source of steroidal saponins.

Another plant extract, Bulbine Natalensis is a potent South African herb that has been shown to outperform Viagra in the laboratory and increasing testosterone by as much as 346% in lab rats. There are, however, side effects with taking this supplement that hinder its wider popularity including having a toxic effect on both the liver and kidneys.

Tongkat ali (or Malaysian ginseng) is another natural remedy for low testosterone levels with good evidence to support the fact that daily supplementing can help maintain normal base levels. There is little evidence that the plant can increase levels beyond normal ranges (other than anecdotally) but if you suffer from low T-levels then tongkat ail is a good way to give yourself a boost in the right direction.

Another ginseng, ashwaganda, is used in traditional Ayurveda medicine to support sperm production and reproductive health with an added side effect of improved testosterone levels. Clinical trials have shown that healthy adult males can expect an increase of testosterone by up to 50% with regular use.

Lastly, there are a large number of ways in which you can improve your testosterone levels without even needing to resort to dietary supplements; changes to your lifestyle and diet plus avoiding certain environmental factors can all help.

To find out more about boosting testosterone naturally, you can read our guide here.

Featured image via Flickr.

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