I copied the item description and here is what it states,it's fairly cheap as well.Biosterol is a new generation product for boost testosterone level and also the product for support sportsperson’s diet. The selection of the compounds was oriented for an effect which increase testosterone production and also physical activity stimulation, which enable to accomplish training scheme. While providing such type of compounds, it can increase the amount of the generating testosterone even to 4 mg within twenty-four hours. This free testosterone provide a metabolic effect. Thanks to the surplus, so-called free testosterone is appearing in the blood. Anabolic potential in this product is more powerful than in the other traditional extract from Tribulus Terrestris. Biosterol is a steroid saponin concentrate. It increases the level of testosterone by stimulating production of LH ( luteinising hormone ). It improves metabolic processes causing an increase in muscle mass. Product can increase amount of body testosterone produced by up to 4 mg per day. Due to this surplus, the so called free testosterone emerges in blood, which is not bound to any proteins. This free testosterone ensures a metabolic effect.