Save On Twinlabs 1X 100 Cap L-Arginine 500MgEach Capsule Provides 500 Mg Of L-Arginine (From L-Arginine Hydrochloride, L-Arginine). As An Amino Acid, L-Arginine Acts As One Of The Building Blocks For Protein.: (Note: This Product Description Is Informational Only. Always Check The Actual Product Label In Your Possession For The Most Accurate Ingredient Information Before Use. For Any Health Or Dietary Related Matter Always Consult Your Doctor Before Use.)