N-Acetyl Cysteine (NAC), is an antioxidant that has been shown in studies to help people with PCOS improve fertility, reduce inflammation and oxidative stress, and improve metabolic complications of PCOS including insulin resistance, fatty liver, and high cholesterol.

120 Capsules. Vegetarian. Gluten-free. Non-GMO

N-acetyl cysteine (NAC)

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N-Acetyl Cysteine (NAC) is both an antioxidant and amino acid (building blocks of protein). Specifically, NAC is a derivative of the amino acid L-cysteine, an essential precursor used by the body to produce glutathione. Glutathione is an extremely important and powerful antioxidant produced by the body to help protect against free radical damage, and is a critical factor in supporting a healthy immune system.

Research shows that women with Polycystic Ovary Syndrome (PCOS) have higher levels of oxidative stress which can contribute to ovarian dysfunction and hormone imbalance. Oxidative stress occurs from free radical or cell damage. As a powerful antioxidant, NAC works to increase glutathione to neutralize or repair damaged cells.

NAC is widely sold in Europe as a treatment for the common cold and it has other numerous uses from being a treatment for bronchitis to removing heavy metals and environmental pollutants from the body. NAC has also been found to reduce inflammation, heart disease and most recently, insulin.


N-Acetyl Cysteine (NAC) may help:*

  • Improve insulin resistance
  • Lower cholesterol levels
  • Improve non-alcoholic fatty liver disease
  • Protect against free radical damage and oxidative stress
  • improve  pregnancy and ovulation
  • Provide Immune support
  • Aid in detoxification

“I’m hoping this gets back to whom ever invented this product! I’m pregnant!!! I can’t positively say it was the reason for this but I hope that more women get a chance to use your product and hopefully end up pregnant too! Thank you from the bottom of my heart!” Elizabeth S. 

N-Acetyl Cysteine (NAC) vs. Metformin in PCOS

Two studies have compared the effects of NAC or Metformin in women with PCOS.

In the most recent study published in Gynecological Endocrinology, a randomized double-blind clinical trial involving 94 women with PCOS compared NAC 600 mg, three times a day with 500 mg oral metformin, three times a day for 24 weeks.

The researchers found that NAC can improve lipid profile and fasting blood sugar and fasting blood insulin better than metformin.

These results are confirmed with an earlier study, published in the European Journal of Obstetrics, Gynecology and Reproductive Biology which compared the effects of NAC and metformin on insulin levels. In this prospective trial, 100 women with PCOS were divided to receive metformin (500mg three times daily) or NAC (600mg three times daily) for 24 weeks.

Both treatments resulted in a significant decrease in body mass index, hirsutism, fasting insulin, free testosterone and menstrual irregularity.

Both treatments had equal effectiveness. Furthermore, NAC led to a significant decrease in both total cholesterol and low-density lipoprotein levels, whereas metformin only led to a decrease in total cholesterol level.

This research supports findings published in the Journal of Fertility and Sterility in 2002 where researchers reported significant improvement in insulin levels among women with PCOS who took 1.6-3g/day of NAC and who had elevated insulin levels before the start of study. Women also showed improvements in testosterone, cholesterol and TG levels.

NAC and Fertility in PCOS

When used with clomid, NAC has been shown to improve ovulation and pregnancy rates in PCOS women by thickening endometrial thickness. 100 women with PCOS who randomly received NAC plus clomid had more endometrial thickness and ovulatory follicles than women who just took clomid or clomid plus metformin.

NAC was also shown to improve oocyte and embryo quality in Iranian women undergoing intracytoplasmic sperm injection.

In a systematic review and meta-analysis involving eight randomized controlled trials with 910 women published in Obstetrics and Gynecology, showed that NAC had significant improvement in pregnancy and ovulation rate as compared to placebo.

Side Effects

Overall, NAC is well tolerated but can cause gastrointestinal adverse effects including nausea, abdominal pain, vomiting, constipation, and diarrhea, particularly when used in high doses. The therapeutic dosage of NAC to improve insulin levels based on published studies is 1.6-3 grams/day. If you are overweight, you may benefit from the higher end of the dose range. Fulghesu et al found that obese patients with PCOS did not respond to doses under 3 grams/day. You should not exceed 7grams/daily. As with any nutrition supplement, it is important to discuss use with your physician before taking.

Read more about NAC and PCOS here



Javanmanesh F, Kashanian M, Rahimi M, Sheikhansari N.A comparison between the effects of metformin and N-acetyl cysteine (NAC) on some metabolic and endocrine characteristics of women with polycystic ovary syndrome. Gynecol Endocrinol. 2015 Dec 10:1-5.

Maged AM, Elsawah H, Abdelhafez A, Bakry A, Mostafa WA.The adjuvant effect of metformin and N-acetylcysteine to clomiphene citrate in induction of ovulation in patients with Polycystic Ovary Syndrome. Gynecol Endocrinol. 2015;31(8):635-8.

Thakker D, Raval A, Patel I, Walia R. N-acetylcysteine for polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled clinical trials. Obstet Gynecol Int. 2015;2015:817849.

Cheraghi E, Mehranjani MS, Shariatzadeh MA, Esfahani MH, Ebrahimi Z.N-Acetylcysteine improves oocyte and embryo quality in polycystic ovary syndrome patients undergoing intracytoplasmic sperm injection: an alternative to metformin. Reprod Fertil Dev. 2014 Nov 13.

Fulghesu AM, Ciampelli M, Muzj G, Belosi C, Selvaggi L, Ayala GF, Lanzone A. N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome. Fertil Steril. 2002 Jun;77(6):1128-35.

Abu Hashim H, Anwar K, El-Fatah RA. N-acetyl cysteine plus clomiphene citrate versus metformin and clomiphene citrate in treatment of clomiphene-resistant polycystic ovary syndrome: a randomized controlled trial. J Womens Health (Larchmt). 2010 Nov;19(11):2043-8. Epub 2010 Oct 12.

Oner G, Muderris II. Clinical, endocrine and metabolic effects of metformin vs N-acetyl-cysteine in women with polycystic ovary syndrome. Eur J Obstet Gynecol Reprod Biol. 2011 Aug 8.


*FDA regulations strictly prohibit the use of therapeutic or medical claims in conjunction with the sale of any product not approved by the FDA. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

*Individual results may vary. Take only as directed under the supervision of a Physician.

*The information and products presented on this website are not intended as a substitute for the advice or medical care of a qualified physician. No action should be taken solely on its content. You should not use the information on this web site for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment.

*PCOS Nutrition Center, LLC urges you consult with your physician or healthcare provider before starting or modifying any diet, exercise or supplementation program or any other therapy or lifestyle activity related to your health, including the advantages and risks of using of supplemental nutrition products.

*PCOS Nutrition Center, LLC does not imply or advocate the use of any nutritional supplement for any reason, other than to increase dietary intake levels of specific nutrients.

*PCOS Nutrition Center, LLC assumes no responsibility for the improper use of and self-diagnosis and/or treatment using these products. PCOS Nutrition Center, LLC products should not be used as a substitute for medically supervised therapy or as a substitute for prescription medications.

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