N-Acetylcysteine ethyl ester (NACET, NAC-Et) is an antioxidant which acts as a lipophilic prodrug for N-acetylcysteine and subsequently glutathione, with improved bioavailability over N-acetylcysteine itself, and has been researched in animal studies as a potential treatment for diabetic retinopathy. It has also been sold as a "dietary supplement" in combination with glycine under the name GlyNAC-Et as a supposedly improved version of the older glycine-NAC combination GlyNAC which has been claimed to show efficacy in counteracting symptoms associated with aging as well as HIV infection, diabetes and nerve damage. Several related compounds such as ó-glutamylcysteine ethyl ester and glutathione ethyl ester have been investigated for similar applications.