Product Review

Jarrow Formulas N-A-C (N-acetyl-L-cysteine) is a stable form of the amino acid L-cysteine. N-A-C is cysteine that has been modified with an acetyl group are stabilized and made more bioavailable. It is essentially a combination of cysteine and acetic acid, which is a primary component of vinegar. L-cysteine, like cystine and taurine, is a sulfur-containing amino acid that can be produced by the body from the essential amino acid methionine. It is considered a non-essential amino acid for this reason, but is conditionally essential in infants and in the case of certain nutrient deficiencies or debilitating conditions. Inadequate methionine in the diet, low selenium intake, chronic disease, and advancing age reduce the body's ability to convert methionine to cysteine. Likewise, stress and environmental toxins may increase the need for cysteine beyond the body's capacity for conversion. N-A-C is preferred to cysteine, or cystine, as a supplement because of its stability, solubility, and greater ability to donate sulfur.