The Gain Trust™




Longjack, or scientifically known as Eurycoma Longfolia Jack (ubiquitously known as Longjack) is a root that contains both alkaloids and glycosides, the therapeutically important components of most medicinal plants (reference 7). Longjack has been used as a naturally occurring aphrodisiac as well as an agent that assists in reducing anxiety and estrogenic effects. Studies also have shown that consumption of longjack can lead to lean mass gain as a result of a potential testosterone increase. To this point there is limited understanding of the human sexual response to longjack, however various studies have led to promising possibilities for the root’s effectiveness on improved physical functionality in humans.


There have been documented instances of Longjack’s ability to improve lean mass gains (reference 5) as well as sexual competence for improving erectile dysfunction and delaying ejaculation (reference 1) reducing anxiety (reference 3) and more. While research around the supplement is constrained to only a few human trials, various testing that has been done on animals has proven Longjack to be effective for the effects described above. Longjack has also been seen to have estrogen-regulating effects that benefited male rats by increasing sperm count (reference 4) while also benefiting female rats by normalizing abnormal estrus phases of the estrous cycle (reproductive cycle of rats) (reference 2).

Side Effects:

One side effect (that can also be considered a benefit in some instances) is longjack’s effect on estrogen levels which can contribute to osteoporosis, hot flashses, vaginal dryness and breast atrophy in women. According to Ray Sahelian, MD, who is certified by the American Board of Family Practice, longjack can still be appropriate for women, particularly those suffering from sexual dysfunction, in small amounts. Additionally, excess dosages (over the recommended dosing) can lead to insomnia, restlessness and irritability (reference 6).


No synergies of note.


Typical doses of longjack are between 200mg-300mg (99% potency) taken up to twice daily.


Further Reference:

1.       Chiou WF, Wu TS 9-Hydroxycanthin-6-One Induces Penile Erection and Delays Ejaculation . J Sex Med. (2011)

2.   Abdulghani M, et al The ameliorative effects of Eurycoma longifolia Jack on testosterone-induced reproductive disorders in female rats . Reprod Biol. (2012)

3.   Ang HH, Cheang HS Studies on the anxiolytic activity of Eurycoma longifolia Jack roots in mice . Jpn J Pharmacol. (1999)

4.   Wahab NA, et al The effect of eurycoma longifolia Jack on spermatogenesis in estrogen-treated rats . Clinics (Sao Paulo). (2010)


6.  Ray Sahelian, M.D. (2015)

7.  Levetin and McMahon Planets and Society, 1995,