N-Acetylcysteine (NAC)

Acetylcysteine is a pharmaceutical drug and nutritional supplement used primarily as a mucolytic agent and in the management of paracetamol overdose. Acetylcysteine is a derivative of cysteine; an acetyl group that is attached to the nitrogen atom. This compound is sold as a dietary supplement commonly claiming antioxidant and liver protecting effects. It is used as a cough medicine because it breaks disulfide bonds in mucus and liquefies it, making it easier to cough up.Acetylcysteine serves as a prodrug to L-cysteine which is a precursor to the biologic antioxidant, glutathione and hence administration of acetylcysteine replenishes glutathione stores. L-cysteine also serves as a precursor to cystine which in turn serves as a substrate for the cystine-glutamate antiporter on astrocytes hence increasing glutamate release into the extracellular space.