Tribulus in order to boost testosterone production naturally. GAT Tribulus is a dietary supplement manufactured and sold by GAT Sport, a company that has been selling sports supplements for almost 20 years now. The main ingredient in GAT Tribulus is as you’ve probably already guessed, Tribulus Terrestris. The herb was traditionally used in Ayurvedic medicine in enhancing sexual health and as an aphrodisiac among other things. Today, Tribulus Terrestris is mainly touted as a testosterone-increasing miracle and, as such, is very popular among athletes.