PROTEIN METABOLISM*/NITRIC OXIDE PRECURSOR*: Arginine supports protein metabolism and is heavily involved in muscle metabolism through its role in the maintenance of a proper nitrogen balance.* Mix 2 level teaspoons daily as needed in at least 8 oz. of juice or water, preferably on an empty stomach. The Informed-Sport seal is your assurance that each and every production run of these NOW Sports products has been tested for banned substances by LGC, a globally recognized assurance program for anti-doping in sports nutrition products. In addition to production run testing, Informed-Sport-certified products are also blind-sampled at the retail level up to four times annually, and testing results can be found at informed-sport.com. Informed-Choice is an adulteration monitoring program through LGC that conducts monthly blind batch testing of registered products at the retail level and posts updated results on their website. The Informed-Choice logo indicates that these products have been tested for, and certified to be free of, banned substances through the Informed-Choice certification program.