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Tongkat Ali's likely hormonal pathway
By Serge Kreutz
Version 2.1, Pescara, 16. August 2010
Tongkat ali increases testosterone tone, but is not a testosterone agonist. Anabolic steroids are testosterone agonists. They cause a negative feedback reaction of the pituitary and hypothalamus (the two glands secrete a series of hormones that signal Leydig and other testosterone synthesizing cells to stop testosterone production). The result is a definite shrinkage of the male genitals, especially the testes. The medical term for the condition is "tesicular atrophy".
Tongkat ali is the opposite of a testosterone agonist. But no, it's not a testosterone antagonist. Tongkat ali stimulates testosterone production by interfering with the testosterone negative feedback loop. Even when tongkat ali raises testosterone levels, the upstream pituitary and hypothalamus do not respond by signaling that testosterone synthesis should be tuned down.
The above is part abstract, part model. Tongkat ali has not been fully researched yet. While there is ample evidence that it raises testosterone, the exact mechanism by which it achieves this hasn't been established.
However, there is educated speculation not only by this author.
Stated Lie-Chwen Lin (National Research Institute of Chinese Medicine, Shih-Pai, Taipei 112, Taiwan, R.O.C.) and Chen-Yuan Peng, Hsing-Shun Wang, Kuo-Wu Lee, and Paulus S. Wang (all of the Department of Physiology, National Yang-Ming University, Shih-Pai, Taipei 112, Taiwan, R.O.C.) wrote in a scientific study into the Chemical Constituents of tongkat ali (Eurycoma longifolia by scientific name):
"A preliminary screening demonstrated that the ethanolic extract of Eurycoma longifolia could increase the human chorionic gonadotropin (hCG)-induced production of testosterone by Leydig cells."
For an abstract of the above-cited article, please see: