Bulk N-Acetyl L-Cysteine, more commonly known as NAC, is a pre-cursor to Glutathione. L-Cysteine can be found naturally in the body as well as in foods such as chicken, red peppers and egg yolks. However, supplementing with L-Cysteine is extremely unstable, whereas N-Acetyl L-Cysteine provides a stable form. The specific form NAC cant be obtained via the diet, and in this popular powdered form can be easily added to water and/or other drinks for easy consumption on the go.