N-acetyl-L-cysteine (NAC) is the acetylated form of L-cysteine that has been used to speed up hair growth and break up pulmonary and bronchial mucous. It is very efficiently absorbed and has been shown to protect cells directly and support hair growth. NAC is an antioxidant and a free radical-scavenging agent that increases intracellular glutathione at the cellular level. NAC can act as a precursor for glutathione synthesis as well as a stimulator of the cytosolic enzymes involved in glutathione regeneration. Durk Pearson and Sandy Shaw detailed the hair growth stimulating effects of Cysteine in their groundbreaking book, Life Extension-a Practical Scientific Approach. 2 or more capsules a day are recommended for faster hair growth.
Directions: Take one capsule one to three times daily with or without food, or as recommended by a healthcare practitioner.
Cautions: Those who supplement with NAC should drink six to eight glasses of water daily to prevent cysteine renal stones. Cysteine renal stones are rare but do occur.