Since 1968, when it was originally licensed, scientists have learned much about the uses of NAC. This amino acid derivative’s structure and attributes help the human body to use it to remedy a wide variety of medical conditions. Being an amino acid, it has nitrogen as part of its amine (NH) group. This allows it to contribute to the body’s nitric oxide (NO) stress response, which helps to return physiological functions back to normal levels following a stressful event.
N-Acetyl L-Cysteine supplements also boost the body’s overall glutathione levels. Of the three amino acids assembled into it, cysteine is the one that is the most limited in its supply in the body. This is due to it being a semi-essential amino acid that the body can sometimes only synthesize in limited amounts. By preventing glutathione depletion, NAC offers multiple medicinal uses.
Recommendations range from 100 mg per dose to 1.8 grams per day. Although it is not yet considered an approved use of this supplement, there are doctors who recommend 200 mg per alcoholic drink to counteract the toxic effects of high blood levels of acetaldehyde.
Mode of Action
The structural formula for N-Acetyl L-Cysteine is CH3-CO-NH-CH(COOH)-CH2-SH. It is the thiol (SH) group that offers one of its antioxidant functions. It does so by releasing the hydrogen (H) atom, which can then neutralize free radicals. Also, the body is able to convert NAC to L-cysteine by removing the acetyl (CH3CO) group. This amino acid is one of three that combine to form glutathione, a tripeptide with strong antioxidant properties.
Glutathione is also responsible for the supplement’s ability to detoxify the body in cases of acetaminophen overdose and, some research supports, alcohol toxicity. It is both the antioxidant and anti-inflammatory properties of N-Acetyl L-Cysteine that provide it with its mucolytic, or mucus-dissolving, properties. These functions combine to make cysteine and glutathione two major contributors to cell protection throughout the body.
Although some sources have suggested that extremely high doses, larger than 7 grams, of N-Acetyl L-Cysteine might be toxic or in humans, there is no LD50 data available for this supplement. However, due to research with rodents, it is known that, for them, a lethal dose lies somewhere between 2 and 4 grams per kilogram for orally administered NAC.