The Potential Benefits of Horny Goat Weed
For years, I have been aware of horny goat weed, an herb often touted as an aphrodisiac that is helpful for male erectile function. Due to the name, I never took horny goat weed seriously. Recently, however, I was researching potential pain treatments and horny goat weed popped up on the list. After a review of the literature, I was surprised by the number of conditions that horny goat weed might help to address.
While a lot of the research on horny goat weed is still preclinical, meaning in animals or on a lab bench, the plant has a long history of use in Chinese herbal medicine. Potential benefits of horny goat weed include:
- Improving sexual function
- Reducing heart disease
- Reversing cognitive decline (early dementia)
- Anti-inflammatory effects
- And others potential benefits…
Horny Goat Weed and Sexual Function
Most research on horny goat weed focuses on a single constituent found in the plant: icariin. Icariin is a yellow-colored compound or flavonoid. In animal studies, icariin has been found to have a number of benefits for sexual function. A study in male mice found that those treated with icariin had increased mating and successful coupling encounters (Ding 2018). The mice also had higher levels of testosterone. A study in rats given penile nerve injuries showed both improved erectile function and increased nerve regeneration with icariin supplementation (Shindel 2010).
Diabetes is well known to increase the risk for erectile dysfunction. In a study on diabetic rats, icariin was able to maintain erectile function as compared to untreated animals (Liu 2011). A separate study on male rats showed increased sperm count and testosterone levels with icariin (Chen 2014). However, when dosing was increased even further, benefits were lost and icariin started to damage reproductive function. Fortunately, the dosage level for this transition was quite high and likely not applicable with normal dosing of horny goat weed. Even still, human studies would be of use to confirm long-term safety.
Horny Goat Weed and Heart Disease
Pulmonary hypertension is a rare type of high blood pressure that involves the blood vessels that lead from the heart to the lungs. Research in rats showed that icariin could significantly protect against the development of pulmonary hypertension and the ensuing heart damage it causes (Li 2016).
Atherosclerosis, or hardening of the arteries, is one of the main drivers of heart disease. Research over the last two decades has been showing a number of anti-atherosclerotic properties of horny goat weed and its active component icariin. As a treatment, icariin appears to help attenuate DNA damage, improve the function of the lining of the blood vessels, suppress inflammatory and immune-mediated plaque formation along blood vessels and decrease blood clotting risk (Fang 2017). These factors combined can work to help prevent atherosclerosis, potentially helping to treat or prevent heart disease.
Horny Goat Weed and Cognitive Decline
Cognitive decline is often the beginning of Alzehiemer’s disease and other forms of dementia. Beta amyloid is one of the main components that makes up the plaques and damage seen in the brain of patients with dementia. In rats injected with beta amyloid, the animals developed learning and memory problems which were reversed by the administration of icariin (Sheng 2017).
A study in aging rats found that icariin was able to preserve cognitive function (Wu 2021). In rats given icariin, brain stem cells were activated which may be part of icariin’s mechanism for improving and preserving cognitive abilities. Other research on mice shows that icariin protects from Alzheimer’s disease by blocking stress signaling pathways involved in protein folding (Li 2019). Additional animal studies have found that icariin protects brain cells even when the brain’s blood supply is limited (Li 2015, Xu 2009).
In mice with three genetic mutations that increase the risk for Alzheimer’s disease, icariin provided significant protection (Chen 2016). Learning and memory were improved, energy production in the brain was preserved and plaque build up was reduced. The author’s even state that icariin may be a multitarget drug that could find use in the prevention of Alzheimer’s disease.
Horny Goat Weed and Inflammation
As the active constituent of horny goat weed, icariin also appears to have potent anti-inflammatory effects. In mice, icariin was shown to be effective for reducing inflammation in the lungs by reducing a number of inflammatory signaling molecules (Xu 2010). Other studies in mice found that icariin protected the kidneys from damage and scarring through its anti-inflammatory effects (Chen 2019). In rats, icariin was also shown to be anti-inflammatory in a model of paw inflammation and swelling (Shitany 2019).
As it progresses, arthritis causes damage to the joint that can accumulate over time leading to increasing pain and disability. In mice, icariin was able to suppress inflammatory injury to the joint connective tissue, thereby helping to maintain normal function (Wang 2020). The authors suggest that icariin may be a candidate drug for treating joint damage.
Data even suggests that the anti-inflammatory properties of icariin may be effective for helping to reverse leaky gut. In older rats, icariin was shown to decrease intestinal inflammation while increasing tight junctions and reducing intestinal permeability (Li 2022).
Other Benefits
And beyond those benefits already mentioned, research also suggests potential of icariin for preserving bone health and for treating cancer (Wang 2018, Tan 2016). While the evidence is still preliminary, the scope of potential applications for horny goat weed and icariin is surprisingly large.
Safety
Currently, the biggest challenge for understanding and utilizing horny goat weed and icariin is the lack of human clinical trials. While the herb has a long history of use, human studies would help to verify benefits and establish effective dosages and treatment regimens in real world situations.
The other main concern with horny goat weed is adulteration. Products for sexual performance enhancement are commonly adulterated with illegal drugs or hormones in an attempt to increase their performance. In many cases, these drugs and hormones are dangerous and may cause significant harm. For clinical use, horny goat weed needs to be purchased from a trusted supplier that tests for product authenticity, adulteration and other contaminants. At a minimum, this should help to ensure that the end user is getting a reputable product.
Conclusion
While the herb has a funny name, horny goat weed appears to have significant potential for treating a number of different medical conditions. Preliminary animal data suggests uses for improving male sexual function, supporting heart health, treating or preventing cognitive decline, improving inflammation and possible helping with bone loss and treating cancer. As it stands, more research is needed to better expand our understanding of horny goat weed, but as an herb, it appears to hold significant promise for a number of challenging-to-treat conditions.
