NACET (N-acetyl-L-cysteine ethyl ester) is the ethyl ester of N-acetyl-L-cysteine (NAC). Esterification of the carboxyl group was intended to increase lipophilicity and cell permeability relative to NAC. Most of the published work comes from one research group in Siena, Italy, which has studied it as a cysteine and glutathione precursor. Research includes pharmacokinetic and tissue glutathione studies in rats, in vitro work in human endothelial and retinal pigment epithelial cells, mouse retinal models and a mouse brain infarction model. A 2018 review covers its chemistry, analysis and pharmacology alongside its S-nitroso derivative, SNACET.