When it comes to PCOS, the key principles should always remain dietary based  However, sometimes a helping hand in the form of supplements can help to improve symptoms.  When it comes to PCOS, there are a range of supplements in the market that have been marketed to have a whole host of benefits.  This article will deepdive in N-acetyl cysteine and will consider the advantages and disadvantages for using it.  Let's get started.

What is NAC? 

NAC Is a semi-essential amino acid and a precursor to the powerful antioxidant, glutathione.  Now, let's back up for a second and explain what these two sciencey-terms mean before we move on.

Amino acids are simply the building blocks of protein.  Semi-essential means that your body can produce it from other amino acids within the body, whereas essential amino acids cannot be produced by our body and we must obtain them from our diet.

Antioxidant is a term used to describe compounds that are able to prevent other compounds known as ‘free radicals' from causing damage to our body.  Think of a free radical like a four-piece puzzle.  It has lost one of its pieces (in science terms it needs an electron) and needs to pick up a piece (aka electron) from somewhere else in order to become complete.  The free radicals damage molecules, DNA and cell structures throughout the body in order to obtain the missing part.  Antioxidants can help prevent this damage from occurring by giving up a piece (aka electron) of their own jigsaw to the free radical, in essence, ‘switching off' the free radical and preventing it from doing any damage.

Now we know this, let's get back to the topic of today: NAC. 

What are the purported benefits of NAC?

Lowers inflammation

Now, let's get something straight. Not all inflammation is bad for the body.  In fact, we need a degree of inflammation in order for our bodies to work optimally and heal after an infection, during a cold and even after exercise in order to get stronger and fitter.  The problem with inflammation when it comes to PCOS is that this is low-grade and chronic which can then go on to lead to all sorts of problems.  Simply put, studies suggest that NAC targets inflammation through its mechanism of increasing glutathione levels; This antioxidant subsequently dampens down chronic inflammation and prevents free-radical damage to the body.

Improved insulin sensitivity

An estimated 70-90% of women with PCOS have insulin resistance.  Read this article for a more thorough explanation of what insulin resistance is if you aren't very familiar with the term.  While the correct nutrition and lifestyle change can significantly improve insulin sensitivity, supplements can also be a helping hand. Studies have shown that supplementing with NAC can reduce the degree of insulin resistance; It is theorised that NAC may help make insulin receptors more receptive to the action of insulin.  One study consisted of 100 women who were divided into two groups.  One group was to receive metformin and the other group was to receive NAC for 6 months.  Both groups had marked reductions in free testosterone, fasting insulin and excess hair growth on the body.  Menstrual cycles also became more regular.

Reduced androgen levels

Women with PCOS often suffer from irregular periods, acne, excess body hair growth and hair thinning from the head.  The cause of these symptoms is elevated testosterone levels, often on the background of insulin resistance.  Studies have shown mixed results- some have reported that the use of NAC can lead to a marked reduction in testosterone levels, while others have not shown the same benefits.

Improving Fertility

The most common cause of fertility issues in women of reproductive age is PCOS.  The hormonal imbalance often leads to issues with ovulation, leading to fewer opportunities for getting pregnant throughout the year.  Studies have shown that supplementing with NAC leads to significant improvements in ovulation, pregnancy and live birth rates when compared to taking a placebo.  In addition, one study showed that egg and embryo quality had improved in women who were undergoing intracytoplasmic sperm injection. Moreover, when used alongside clomid, NAC was shown to improve ovulatory follicles and the thickening of the womb lining, more so than when taking clomid alone or when taking clomid and metformin.

However, when compared to women with PCOS being treated with metformin, those taking NAC were less likely to get pregnant or ovulate.

Improving Fatty Liver

Women with PCOS have higher incidences of fatty liver.  A marked improvement in liver function tests was demonstrated in one study whereby women with PCOS were treated with NAC for 3 months.


Whenever looking at evidence to support the use of supplements, it is important to be aware of study limitations.  For example, with the studies described above, some of them were not carried out to the best standard and while others were of better quality, only one study had shown the benefits.  When it comes to scientific consensus, it is important that studies that show benefit be repeated in order to confirm that the benefit was in fact due to the intervention, and not a coincidence. Furthermore, many of the studies were of a short-term duration of 3 months, meaning that ongoing assessment of the benefits of NAC on PCOS symptoms could not be monitored.

Bottom line: The strongest evidence to support the use of NAC is for helping to improve fertility and egg quality in women with PCOS, in addition to some evidence suggesting that NAC works just as well as metformin to improve insulin sensitivity in women with PCOS.  Although the safety profile of NAC appears to be good, it is important to note that this supplement be avoided in anyone with the following medical history: asthma, hepatic encephalopathy, bleeding disorders, taking blood thinning medication or has had a gastric hemorrhage.

If you are struggling with unwanted hair, constant fatigue, uncontrollable cravings and weight that is just not shifting, then you will likely benefit from a targeted nutrition and supplement plan to ease your symptoms.  Click here to book a FREE strategy call and we can discuss how putting together a step-by-step plan will help you reverse your symptoms once and for all.