L-Arginine found in SilverOnyx Nitric Oxide supplements is an amino acid which can be converted to nitric oxide. Our nitric oxide support supplement also contains citrulline malate. Supplement Facts (per 2 Veggie Capsules): Niacin - 15mg Calcium (as Calcium Carbonate) - 36 mg L-Arginine - 400mg L-Arginine AKG 2:1 Extract - 400mg L-Citrulline - 200mg L-Citrulline Malate Extract - 200mg Beta Alanine - 80mg Inactive Ingredients: Cellulose (Vegetable Capsule), Magnesium Stearate (Vegetable), Silicon Dioxide. Each batch of our SilverOnyx Nitric Oxide Arginine Supplement is proudly manufactured and bottled in the USA facility following strict cGMP guidelines. Third party reviewed for purity and quality by an experienced dietary supplement laboratory.