Acetyl L-Cysteine is a potential antioxidant and is also used as a mucolytic agent. It is effective for the treatment of paracetamol intoxication. It imparts its mucolytic action more commonly as adjuvant, usually in respiratory disorders associated with thick or excessive mucus production like bronchitis, cystic fibrosis, tuberculosis, pneumonia, emphysema, amyloidosis. It also acts as an antiviral agent by inhibiting HIV replication. It is also popular as a dietary supplement due to its antioxidant property.