Neuroscience Research Compound · For laboratory research use only
Also known as N-Acetylcysteine Ethyl Ester
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 NAC1. Most of the published work comes from one research group in Siena, Italy, which has studied it as a cysteine and glutathione precursor1,2,3,4.
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 model1,2,3,4,5. A 2018 review covers its chemistry, analysis and pharmacology alongside its S-nitroso derivative, SNACET6.
As described in the research literature
As described in the research literature, NACET was rapidly absorbed in rats but reached very low plasma concentrations, because it entered cells and was trapped there after conversion to NAC and cysteine. It increased glutathione content in most tissues examined, including brain, and accumulated in human erythrocytes in vitro1.
In primary human umbilical vein endothelial cells, NACET was the most efficient of four compounds compared at raising intracellular glutathione, cysteine and gamma-glutamylcysteine. The rise in glutathione levelled off and then declined at higher concentrations, which the authors traced to competitive inhibition of glutamate-cysteine ligase by the NAC released from NACET2.
In retinal pigment epithelial cells, NACET increased the expression and activity of the transcription factor NRF2. RNA interference, mass spectrometry and KEAP1 mutagenesis identified direct cysteinylation of the KEAP1 sensor residues Cys226 and Cys613 as the mechanism4.
What published studies have examined
Rat studies compared NACET with NAC for absorption, plasma levels, tissue glutathione and protection in a paracetamol intoxication model, and examined erythrocyte accumulation and hydrogen sulfide1. Human endothelial cells were used to compare NACET with NAC, 2-oxothiazolidine-4-carboxylic acid and glutathione ethyl ester2. The chemistry and analytical methods for NACET are reviewed in6.
Retinal pigment epithelial cells under oxidative stress were used to compare cell viability and intracellular glutathione after NACET or NAC, and eye glutathione was measured in rats3. A 2025 study examined NRF2 activation in the retina, retinal ageing hallmarks and diabetes-induced retinal neurodegeneration in mouse models4.
In photochemically induced thrombosis model mice, NAC, NAC ethyl ester and NAC benzyl ester were compared for infarct size, and detoxification of acrolein through glutathione S-transferase-catalysed conjugation was examined5.
Sources [5]
N-Acetylcysteine ethyl ester (NACET): a novel lipophilic cell-permeable cysteine derivative with an unusual pharmacokinetic feature and remarkable antioxidant potential.
Giustarini D, Milzani A, Dalle-Donne I, et al. Biochemical Pharmacology, 2012.
N-acetylcysteine ethyl ester as GSH enhancer in human primary endothelial cells: A comparative study with other drugs.
Giustarini D, Galvagni F, Dalle Donne I, et al. Free Radical Biology & Medicine, 2018.
Superior Properties of N-Acetylcysteine Ethyl Ester over N-Acetyl Cysteine to Prevent Retinal Pigment Epithelial Cells Oxidative Damage.
Tosi GM, Giustarini D, Franci L, et al. International Journal of Molecular Sciences, 2021.
N-acetyl-l-cysteine ethyl ester (NACET) induces the transcription factor NRF2 and prevents retinal aging and diabetic retinopathy.
Realini G, Amato R, Rasa M, et al. Redox Biology, 2025.
Protective Effects of Brain Infarction by N-Acetylcysteine Derivatives.
Uemura T, Watanabe K, Ko K, et al. Stroke, 2018.
S-Nitroso-N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)-Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H(2)S and GSH suppliers and as antioxidants: Results and overview.
Tsikas D, Schwedhelm KS, Surdacki A, et al. Journal of Pharmaceutical Analysis, 2018.
This page is provided for research and educational reference only. It does not constitute medical advice, dosing guidance, or a recommendation for use. All compounds are strictly for laboratory and in-vitro research purposes.