This herb works through different mechanisms to benefit both sexes. Here's the science.
There have been a lot of studies showing that the decidedly cool-sounding supplement, Tongkat Ali (an extract of the Eurycoma longifolia bush), elevates testosterone levels in men. However, a fairly recent study of older bicyclists found that the herb raises testosterone levels in women as well as men.
What the Researchers Did
Ralf Henkel of the University of the Western Cape in South Africa and Ruxiang Wang of the Shenyang Center for Disease Control and Prevention in China recruited 25 older cyclists, 13 of them male and 12 of them female. All of them belonged to the same over-50 cycling club.
Each cyclist received 200 mg. of Tongkat Ali every day for five weeks. The researchers took before, during, and after measurements of cortisol, IGF-1, DHEA, testosterone, and grip-strength.
While levels of cortisol, IGF-1, and DHEA remained largely unchanged, free and total testosterone levels went up significantly in both men and women, as did grip strength. The top graph shows the changes in the testosterone levels of men and the second graph shows the changes in the women:
Clearly, the Tongkat Ali raised testosterone levels in both sexes and consequently increased their strength, too.
While the testosterone increases in men were apparently caused by elevated luteinizing hormone (LH) and follicle stimulating hormone (FSH), along with concurrently lowered estradiol levels, the increase in women's testosterone levels was believed to be caused by a significant decline in sex-hormone binding globulin (SHBG).
That means that the herb prevented the testosterone that women make naturally from being chemically bound up and made inaccessible to the body by SHBG.
What These Findings Mean To You
Older men and women can benefit from taking Tongkat Ali to raise testosterone levels, and while it's true that previous studies have concentrated on its testosterone-elevating effects in younger men, it's not known whether these findings would hold true for younger women, too.
Younger women generally have lower SHBG levels than older women, and thus might not feel much of a difference from Tongkat Ali. Younger women also have to be wary about the potentially masculinizing effects of elevated levels of testosterone.
However, if you're a man who feels he might benefit from higher levels of testosterone (or an older woman who feels the same), try taking a daily dosage of at least 200 mg. of Tongkat Ali. Two capsules of the formula Alpha Male® contain the same amount of highly purified Tongkat Ali used in the study.
While forskolin has been shown to elevate testosterone in men, it doesn't have the same effect in women. Instead, it works to reduce female belly fat. Similarly, while some studies of Tribulus Terrestris have shown it to increase testosterone production in men, it only stimulates androgen receptors in women's brains, thus helping them respond better to their natural levels of circulating hormones.
- Henkel RR, Wang R, Bassett SH, Chen T, Liu N, Zhu Y, Tambi MI. "Tongkat Ali as a potential herbal supplement for physically active male and female seniors–a pilot study." Phytother Res. 2014 Apr;28(4):544-50.
- Akhtari E, Raisi F, Keshavarz M, Hosseini H, Sohrabvand F, Bioos S, Kamalinejad M, Ghobadi A. "Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study." Daru. 2014 Apr 28;22(1):40.
- Shonteh Henderson, Bahrat Magu, Richard B Kreider, et al. "Effects of Coleus Forskohlii Supplementation on Body Composition and Hematological Profiles in Mildly Overweight Women." J Int Soc Sports Nutr. 2005; 2(2): 54–62.