Furthermore, studies have shown that lack of testosterone leads to a range of other sexual performance problems, including premature ejaculation and low sex drive. Stimulation of the penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. John Brinkley initiated a boom in male impotence cures in the U.S.
There are two forms of impotence: primary and secondary. The active ingredient of Tribulus acts as a natural precursor to these hormones and is converted into its final forms by the body's own natural enzymes. The vacuum forces blood into the penis, which in turn causes an erection.