The motility of sperm and their ability to penetrate the female egg, as well as the volume and concentration of sperm play an important role in the fertilization of the female egg.
A 1996 study conducted by L. Setiawan Airlangga University, Surabaya, Indonesia, investigated the effect of Tribulus terrestris on men with oligoasthenoteratospermia (OAT), a common cause of male infertility.
The study was conducted on 30 men with primary and secondary infertility.
Fifty percent of the men took oral Tribulus or Libilov, 500 mg three times daily for 60 days, and the rest took sugar pills.
Data were assessed before and after treatment.
Tibullus terrestris administered at a dose of 500 mg three times daily for 30 days was found to be effective in restoring sperm functions, such as motility and acrosome reactions, or when sperm receptors came into contact with the egg.