N-acetylcysteine (aka NAC) has wide-ranging benefits, from calming symptoms of obsessive-compulsive disorder to boosting fertility.

N-acetylcysteine (aka NAC) has wide-ranging benefits, from calming symptoms of obsessive-compulsive disorder to boosting fertility

The name may be a bit of a tongue twister, sounding right out of a biochemistry book, but the benefits are straightforward and impressive. N-acetylcysteine (acronym NAC) is formed through the combination of cysteine (a building block of protein) and a molecule related to acetic acid (found in vinegar). Compounds very similar to NAC are found in garlic, which may explain some of that food’s many health benefits.
NAC is a potent antioxidant. It is the precursor to glutathione, the most powerful antioxidant made by the body, and is a rich source of sulfur, a mineral needed to make some vitamins, hormones, and tissue. In fact, because of its sulfur content, NAC supplements can smell like rotten eggs—so take capsules without sniffing them!


1. The Flu

NAC may be the ultimate—and safest—flu and cold fighter available. In a study of seniors during the cold and flu season, people supplementing with NAC (600 mg twice daily), developed relatively few flu symptoms when infected. NAC controlled the respiratory symptoms of the flu and, through its conversion to glutathione, boosted the body’s ability to fight infection.

2. Polycystic ovary syndrome (PCOS)

Women with PCOS suffer from enlarged cystic ovaries, high levels of male hormones, and prediabetic insulin resistance. Many women with PCOS also suffer from infertility, as eggs are unable to develop and leave the ovaries. In a study involving 150 women who had previously failed to respond to a fertility drug, those who added NAC to their fertility drug treatment showed dramatically improved fertility than those taking the drug and a placebo. Almost 50% of the women taking NAC ovulated compared to about 1% in the drug group. Pregnancy rate in the NAC group was 21%, compared to 0% in the drug-only group.

3. Obsessive-Compulsive Behaviors

NAC may help mitigate obsessive-compulsive and self-destructive behaviors. In two reports from Yale University, doctors found that NAC reduced the desire to compulsively wash hands and to self-mutilate. The Yale School of Medicine website states, “Evidence suggests that the neurotransmitter glutamate is out of balance in at least some cases of OCD …we have found NAC to improve OCD symptoms. Recent results from other groups have suggested that NAC is effective in treating trichotillomania (pathological hair-pulling), which may be related to OCD.” The supplement seems to help regulate serotonin and dopamine levels in the brain.

TIP: Clear Up Congestion

If you have a respiratory infection with lung and/or sinus congestion, try NAC supplements. The remedy is often recommended to break up mucus.

Uses Worth Noting

NAC is used by many hospitals to treat acetaminophen overdose. Large amounts of acetaminophen deplete the liver’s glutathione, which is needed to detoxify hazardous chemicals. Without glutathione, the liver itself will break down. NAC quickly restores levels of glutathione and promotes normal liver function. Other research points to NAC’s ability to heal kidney damage and reduce risk of kidney complications after an angioplasty.

Dosage Guidelines

The standard dosage is 500-600 mg of NAC daily; this amount can be doubled during cold and flu season. Work with a qualified practitioner if you are trying to address a specific condition.

Solgar NAC 600mg

Solgar NAC 600 mg provides free form NAC to promote optimal absorption and assimilation. Capsules are suitable for vegetarians.


KAL NAC + 600  This comprehensive formula gives you 600 mg of NAC per tablet, plus vitamin B12, calcium, and molybdenum.

Vitamin Shoppe NAC 600mg

The Vitamin Shoppe NAC 600 MG is a high-quality supplement free of common allergens, artificial colors, or preservatives.

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