In this article, we’ll dive into the facts about N-acetyl-L-cysteine, or NAC, and if it can help you get pregnant.


By fertility warrior and women’s health expert Halle Tecco

N-acetyl-L-cysteine, or NAC, is a powerful antioxidant thought to reduce DNA damage. It is used as a prescription drug to treat acetaminophen overdose. Over the years, it has also been tried as a cure for many things—cancer, depression, HIV—but clinical studies are mixed.  So should you take NAC for fertility?

Unfortunately, there is little evidence that N-Acetyl Cysteine supplementation improves fertility. One small study in Iran did find that NAC improved egg and embryo quality in women with PCOS undergoing IVF, but the study was small and hasn’t been replicated. 

NAC for PCOS and ovulation

There is not enough compelling data to recommend NAC as a treatment for PCOS. One small study published in Fertility & Sterility compared the impact of taking N-acetyl cysteine or metformin in women with PCOS. For those who took metformin, the rate of ovulation was 51.6%. However, the N-acetyl cysteine group did not see an improvement, with an ovulation rate of only 6.7%. 

However, a meta-analysis of eight randomized controlled trials with 910 women found that while NAC did not improve menstrual regularity, glucose, or insulin levels, it did improve rates of live births and ovulation in women with PCOS. But when compared with metformin, NAC had fewer benefits. If you are struggling with PCOS, we suggest talking to your doctor about your options. 

What do doctors say about NAC?

Dr. Eric Surrey, a reproductive endocrinologist at the Colorado Center for Reproductive Medicine says there’s little data to show NAC’s efficacy.

“I would very much caution women who don’t have diagnosed fertility issues from taking NAC supplements,” says Dr. Surrey. “In fact, it can impact blood clotting in women going in for surgery because it’s a blood thinner.”

Where can I buy NAC?

NAC is mostly available by prescription, so talk to your doctor. There are some over-the-counter NAC supplements (500 mg to 1,000 mg tablets); however, it can be hard to find. This is because the FDA issued warning letters that NAC couldn’t be lawfully marketed in dietary supplements because it was first studied as a drug in 1963. Due to this, Amazon stopped carrying NAC supplements in 2021.

NAC or CoQ10 for fertility success?

Coenzyme Q10 (CoQ10) has been a popular topic of discussion in the medical infertility community for some time now and is a widely recommended supplement by fertility doctors. CoQ10, also known as ubiquinone, is a naturally occurring antioxidant found in every cell within the human body. Several studies have shown the benefits of taking CoQ10 supplementation during fertility treatments. CoQ10 is also sometimes used for male fertility

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Before starting any supplement routine for fertility or otherwise, you should always discuss it with your doctor. 

Is NAC safe?

NAC is likely safe for adults when provided as a prescription medication. However, high amounts can come with side effects including upset stomach, diarrhea, nausea, vomiting, fatigue, and skin rash. If you have any side effects, talk to your doctor immediately. 


  • NAC is a powerful antioxidant thought to reduce DNA damage.
  • NAC is a prescription medication.
  • NAC is sold over-the-counter; however, the FDA has issued warning letters to companies marketing NAC as a supplement.
  • NAC is likely safe when prescribed as a prescription medication.

IVF can be an amazing way to grow a family. I know—I would not be a mother today without IVF. But it also comes with emotional ups and downs. If you want to learn more about fertility treatments, sign up for my personal IVF newsletter. 💌 


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Featured Image by Pok Rie