5 Benefits of N-Acetylcysteine

N-acetylcysteine, simply known as NAC, is a powerful antioxidant that may provide the following benefits for people with polycystic ovary syndrome (PCOS):

  • Boost fertility
  • Improve insulin resistance
  • Restore hormone balance
  • Fight inflammation
  • Help liver function

Known in Europe for decades as an immune-boosting supplement and a popular treatment for bronchitis, NAC is emerging as a promising integrative treatment for women who are having complications from PCOS.

This article discusses these five potential benefits of NAC for PCOS.

Woman holding a supplement
Paul Bradbury / Getty Images

Boosts Fertility

For the approximately 70% of women with PCOS who experience infertility, NAC may offer some hope.

A 2015 systematic review and meta-analysis published in the Journal of Obstetrics and Gynecology looked at the benefits of NAC in eight randomized controlled trials involving 910 women with PCOS. The review showed that NAC provided significant improvements in ovulation, as well as pregnancy and live birth rates as compared to a placebo alone.

NAC has been shown to have similar benefits as metformin for improving pregnancy rate, spontaneous ovulation, and improving menstrual regularity in women with PCOS.

For women who are resistant to Clomid, NAC may help to improve their fertility as well. A 2014 study published in the European Journal of Obstetrics, Gynecology, and Reproductive Biology found that NAC users had a nine times higher ovulation rate and a five times higher pregnancy rate in Clomid-resistant women as compared to a placebo.

Improves Insulin Resistance

NAC can protect insulin receptors and influence insulin receptor activity secretion from the pancreas cells. As a result, NAC can improve insulin resistance.

Although it’s not FDA approved for its use, metformin remains a commonly-prescribed medication to help women with PCOS who have insulin resistance. Several studies have compared NAC and metformin in women with PCOS.

Women who took NAC showed similar results to metformin for improving insulin resistance as well as lowering cholesterol levels, and without experiencing the common gastrointestinal side effects that metformin can cause.

Restores Hormone Balance

A surprising benefit of NAC is that it may have the potential to balance certain hormones.

In a 2019 study published in The Journal of Obstetrics and Gynecology of India, researchers randomized women with PCOS to take metformin (1500 milligrams per day, mg/day) or NAC (1800 mg/day) for 24 weeks.

The group that received NAC showed better improvements in their metabolic and hormonal profiles, which included a greater reduction of total testosterone.

Fights Inflammation

Women with PCOS have been shown to have higher levels of oxidative stress than women without PCOS. High levels of oxidative stress can damage cells and promote inflammation which in turn worsens the metabolic aspects of PCOS.

As a powerful antioxidant, NAC works to fight oxidative stress and reduce inflammation.

Helps Your Liver

Sometimes women with PCOS develop non-alcoholic fatty liver disease (NAFLD). This type of fatty liver disease can result from high insulin and triglyceride levels. It can be reversed with modifications in your diet.

A 2020 analysis published in Antioxidants found that NAC may be able to improve liver function by reducing levels of oxidative stress in those with NAFLD. It may also help reduce certain complications associated with the disease.


Overall, NAC is a well-tolerated dietary supplement that offers numerous benefits to people with PCOS.

If you’re interested in trying NAC to see if it will help you get pregnant or reduce some of the metabolic consequences of PCOS, such as fatty liver and insulin resistance, talk with your healthcare provider and registered dietitian nutritionist. They can determine what dose is appropriate for you.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
  • Oner G et al. Clinical, endocrine and metabolic effects of metformin vs N-acetyl-cysteine in women with polycystic ovary syndrome. Euro J Obst Gynecol Biol. Nov 2011;159(1):127-131.

By Angela Grassi, MS, RDN, LDN
 Angela Grassi, MS, RDN, LDN, is the founder of the PCOS Nutrition Center.