We Know It Can Increase Testosterone, But How?
The mysterious herb, Eurycoma longifolia, aka Tongkat Ali, can increase testosterone. Science has known of its testosterone-raising powers for a while, but she didn't know exactly how it worked until recently. Thanks to some rats that sacrificed their balls to some researchers at the Universiti Sains Malaysia, she now knows.
The answer has to do with two particular quassinoids, which are metabolically altered triterpenes. These quassinoids are named eurycomanone and 13-alpha (21) dihydroeurycomanone. When rats received daily doses of high-quassinoid extracts of Eurycoma, they experienced a considerable rise in testosterone levels with a concurrent decrease in estradiol.
Spermatogenesis also increased substantially, as did the weight of the rat's testicles (indicating more productive leydig cells, more spermatogenesis, and more productive testicles in general). Furthermore, when these "enhanced" rats mated (before their testicles were removed and weighed, of course), they had a higher fecundity batting average and females gave birth to bigger, badder litters.
Chemical analysis showed that the Eurycoma-treated rats had elevated luteinizing hormone (LH) and follicle-stimulating hormone (FSH), both of which play a role in elevating testosterone in mammals. The researchers said that those elevated chemicals, in addition to the reduced estradiol levels, are what caused Eurycoma longifolia to elevate testosterone.
Another study, conducted in South Africa about the same time as the one above, found that Eurycoma, unlike steroids, doesn't shrink the testicles or enlarge the prostate. The researchers discovered this by either giving rats low but still huge, off-the-scale doses of Eurycoma longifolia, or doses of Eurycoma that were larger still (the human equivalent of up to 12 to 16 grams per day).
The rats, regardless of what dose they were taking, experienced varying degrees of improved sperm quality. Furthermore, after the trial, the prostates of both the low dose and the high dose were smaller than control animals. Similarly, the seminal vesicles of the animals receiving the herb didn't shrink.
The effective human dosage of Eurycoma longifolia is around 200 to 400 milligrams a day, so if the mega doses given to animals didn't provoke any negative androgenic side effects, it's not likely that normal, human dosages would either.
If you want to try Eurycoma longifolia, make sure you use a product that's high in the main two active quassinoids, such as Alpha Male®.
- Low BS et al. Standardized quassinoid-rich Eurycoma longifolia extract improved spermatogenesis and fertility in male rats via the hypothalamic-pituitary-gonadal axis. J Ethnopharmacol. 2013 Feb 13;145(3):706-14. PubMed.
- Solomon MC et al. In vivo effects of Eurycoma longifolia Jack (Tongkat Ali) extract on reproductive functions in the rat. Andrologia. 2014 May;46(4):339-48. PubMed.