Ultimate Nutrition BULGARIAN TRIBULUS 90 Caps - Tribulus terrestris is a plant that grows in many tropical and moderate areas of the world. The current research indicates that the steroidal saponins, particularly the dominant saponin protodioscin, are responsible for the pharmacological activities of tribulus. Tribulus terrestris is a testosterone enhancer. It in-part blocks the receptors leading to the hypothalamus misinterpreting the body’s sex hormone levels as being lower than they really are. The hypothalamus signals to start the production of Luteinizing hormone (LH). When LH levels are increased, the natural production of testosterone also increases. LH is a hormone that also deals with sex drive. Naturally contains over 45% steroidal saponins.