Mucolytic

N-acetylcysteine (NAC) is an acetylated form of the amino acid cysteine. It is the standard antidote for paracetamol (acetaminophen) overdose, a mucolytic that modestly cuts flare-ups of COPD and chronic bronchitis, and a widely sold supplement. Its psychiatric uses rest on a mixed record: a positive trial in adolescents who used cannabis failed to repeat in adults, and large trials found no benefit for idiopathic pulmonary fibrosis or for protecting the kidneys during angiography. Only about a tenth of an oral dose reaches the blood.