Ashwagandha powder has numerous benefits for men, the most prominent being its effect on testosterone and fertility.
According to a systematic review and meta-analysis of the available studies, Withania somnifera can increase testosterone levels by 17% on average in infertile males [3].
Moreover, Ashwagandha root extract led to a 59% increase in semen volume, a 57% increase in sperm motility, and a whopping 167% increase in sperm concentration. This was sufficient to revert male infertility and result in pregnancy in 14% of the couples.
Another study also found that the antioxidative benefits of ashwagandha significantly improve sperm count and motility [4]. Treatment of infertile men recovered the seminal plasma levels of antioxidant enzymes and vitamins A, C, and E.
But the benefits of ashwagandha for men do not end here. The herb can also stimulate the function of another of your endocrine glands - your thyroid.
In a trial with 50 participants, 8 weeks of ashwagandha supplementation led to a significant increase in the levels of thyroid hormones and a reduction in TSH [5].
If you are an active man, ashwagandha can also boost your muscle strength and performance. Ultimately this may aid your efforts in maintaining or even increasing your muscle mass.
In one 8-week study, resistance-training men who took ashwagandha had a significantly greater reduction of exercise-induced muscle damage, increased muscle strength, and improved muscle compared to individuals who took a placebo [6].
Ashwagandha may also boost endurance, as another study of 40 men reports that supplementation significantly increased their velocity, physical power, and oxygen capacity [7].
Why does ashwagandha boost testosterone?
The main mechanism via which ashwagandha appears to boost testosterone levels is by lowering another hormone that interferes with the normal function of the testes. That is the stress hormone cortisol, which can lead to reduced testosterone production when its levels are high.
Ashwagandha is a powerful adaptogen that can significantly reduce perceived stress and cortisol levels. One trial reports that the herb can lower your morning cortisol levels by almost 30% after 8 weeks of supplementation [8].
The researchers also note that the reduction in cortisol was associated with a significant increase in testosterone levels.
The cortisol-lowering effects of ashwagandha can also help improve your sleep quality, according to a trial with 58 participants [9]. Your sleep quality is tightly associated with your testosterone production, and every hour of missed sleep lowers your testosterone levels by a whopping 15%.
Therefore, ashwagandha works to improve your testosterone levels by lowering cortisol, reducing stress, and improving your sleep quality.
These benefits are due to the presence of withanolides in ashwagandha root extract and, more specifically, the withanolide called Withanoside IV. Research reveals that out of all the numerous withanolides in the herb, Withanoside IV is the main ingredient that helps reduce cortisol levels [10]