NOW Foods L-Lysine 500 mg provides this essential amino acid that cannot be synthesized by the body and must be obtained from diet or supplementation. Lysine is critical for collagen formation, calcium absorption, carnitine synthesis, and immune function. It is most widely used for managing oral and genital herpes (HSV-1 and HSV-2) — lysine competes with arginine, the amino acid the herpes virus requires to replicate, reducing outbreak frequency and severity when supplemented consistently. Research also supports lysine for improved calcium retention and bone health. NOW Foods provides 500 mg of pharmaceutical-grade L-lysine per capsule — a convenient maintenance dose — manufactured in their GMP-certified facility with identity and purity testing. A simple, affordable supplement with significant evidence for herpes management and collagen support.