N-Acetyl-L-Cysteine (NAC) is the acetylated form of L-Cysteine, which is a conditionally essential amino acid – one of only three sulfur-containing amino acids, the others being Taurine (which can be produced from L-Cysteine) and L-Methionine (from which L-cysteine can be produced in the body by a multi-step process).

L-Cysteine helps synthesize glutathione, the body’s most important intracellular antioxidant and a vital detoxifier. Through its metabolic contribution to glutathione production, cysteine participates in the general antioxidant activities of the body. Through its role as a modulator of the glutamatergic system, cysteine influences the reward-reinforcement pathway.

NAC is free radical-scavenging agent, and is very efficiently absorbed, and has been shown to protect cells directly and support the immune system.