L-cysteine is a conditionally essential amino acid, one of only three sulfur-containing amino acids, the others being taurine (which can be produced from L-cysteine) and L-methionine (from which L-cysteine can be produced in the body by a multi-step process). Cysteine plays a role in the sulfation cycle, acting as a sulfur donor in phase II detoxification and as a methyl donor in the conversion of homocysteine to methionine.136-138 Cysteine also helps synthesize glutathione, the body’s most important intracellular antioxidant and a vital detoxifier.139-142
N-acetyl-L-cysteine (NAC) is the acetylated form of L-cysteine that has been used to break up pulmonary and bronchial mucous.143-146 It is very efficiently absorbed and has been shown to protect cells directly and support the immune system.146-155 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.146 NAC has been shown to protect against oxidative stress-induced neuronal death in cultured granule neurons.156
Servings Per Container: 60
Take one (1) capsule one to three times daily with or without food, or as recommended by a healthcare practitioner.
Serving Size: 1 vegetarian capsule
Amount Per Serving
N-acetyl-L-cysteine ... 600mg
Other ingredients: vegetable cellulose (capsule), vegetable stearate, silica.
Directions: Take one (1) capsule one to three times daily with or without food, or as recommended by a healthcare practitioner.
Caution: Those who supplement with NAC should drink 6 to 8 glasses of water daily in order to prevent cysteine renal stones. Cysteine renal stones are rare but do occur.
Warnings: Keep out of reach of children. Do not exceed recommended dose Do not purchase if outer seal is broken or damaged. When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.
Store tightly closed in a cool, dry place.