Nutricology/ Allergy Research Group, NAC N-Acetyl-L-Cysteine, 120 TabsProduct Description Nac, the acetyl derivative of L cysteine, is more stable than L cysteine, and can convert into L cysteine after being absorbed. Nac is a natural source of sulfur for metabolism, and an antioxidant. Free form amino acid, high purity, well tolerated, and in tablet form to insure potency. Product Benefits Supports Glutathione Synthesis. Acts As An Antioxidant. Ingredients Supplement FactsServing Size: 1 Tablet Amount Per Serving %