Tribulus terrestris is an herb containing steroidal saponins that can have a positive impact on testosterone levels and sex drive. Protodioscin is considered to be the most active compound in tribulus terrestris and many tribulus products are standardized for protodioscin content. Tribulus is suitable for bodybuilders, weight trainers and those desiring maximum male sexual performance.*
Tribulus terrestris is known to enhance testosterone levels by increasing Gonadotropin Releasing Hormone (GnRH), which in turn, increases luteinizing hormone (LH) levels. LH signals cells to produce more testosterone. Tribulus has been used for centuries in Ayurvedic and Chinese medicine.
source: http://www.nutritionexpress.com/supplements/tribulus+terrestris/
