About this item DOUBLE STRENGTH L-ARGININ: Our offers this non-GMO, double strength L-Arginin supplement in 400 mg tablets. NITRIC OXIDE PRECURSOR: Arginine plays an important role in the dilation of blood vessels. CLASSIFICATIONS/CERTIFICATIONS: Non-GMO, Soy Free GMP Quality Assured: GMP certification means that every aspect of the Our manufacturing process has been examined, including our laboratory/testing methods (for stability, potency, and product formulation).