Double Wood's stim free pre workout nitric oxide supplement contains a 1,500mg mix of Nitrosigine, L-Citrulline, and Arginine. The Nitrosigine has been clinically studied to boost nitric oxide flow. Each bottle contains 180 capsules (60 servings). This product is manufactured in the USA, non-GMO, gluten free, and vegan safe, and contains no fillers.