K2 Nutrition Tribulus and Horny Goat Weed. Strongest Testosterone Booster. Natural Performance Enhancer. Ingredients Tribulus 500 mg Horny Goat Weed 200 mg. Ingredients - Vitamin D3, Vitamin K2, Vitamin B6, Magnesium, Zinc, D- Aspartic Acid, Asian Red Panax Ginseng and Fenugreek.