Ethyl N-acetyl-L-cysteinate is the ethyl ester derivative of N-acetyl-L-cysteine (NAC), serving as a lipophilic prodrug with improved bioavailability and membrane permeability compared to standard NAC. It is primarily utilized in research and formulations for enhanced delivery of NAC's antioxidant properties, supporting glutathione synthesis to combat oxidative stress. Potential applications include nutritional supplements for liver protection, neuroprotective effects in neurological disorders, and dermatological products due to better skin penetration. In vivo, it undergoes hydrolysis to release NAC, which can act as a mucolytic agent in respiratory conditions like COPD and cystic fibrosis by cleaving disulfide bonds in mucus.