NAC for PCOS: benefits, dosage and evidence

You may have heard of NAC for PCOS symptom management. Unlike everyday supplements like vitamin C and vitamin D, NAC is a bit more niche. We have written this article to help you learn more about NAC and how it could help with your PCOS. We have also included how you can buy NAC in the UK.

What is PCOS?

Polycystic Ovary Syndrome (PCOS) is one of the most common endocrine disorders. Around 1 in 10 people with ovaries are living with PCOS. It’s a syndrome, which means there is no one-size-fits-all checklist of symptoms. Symptoms often include irregular periods or ovulation, insulin resistance, fatigue, hirsutism,  and infertility.

There is no cure for PCOS, but there are changes that can be made to ease symptoms and reduce the long-term implications of unmanaged PCOS. One of these includes supplement use, including NAC.

>> Read more: PCOS 101 | A beginner’s guide to PCOS

What is N-Acetylcysteine?

N-Acetylcysteine (NAC) is derived from the amino acid L-cysteine. NAC is needed to produce a potent antioxidant, glutathione. The main role of NAC in medicine is to treat acetaminophen (pain killer) overdose. It does this by binding to the painkiller in the liver, thus preventing poisoning.

It has also been used as a popular treatment for bronchitis but has promising benefits for conditions like PCOS too. Let’s take a look at the evidence we have so far.

Potential benefits of NAC for PCOS

NAC has been researched for its role in PCOS symptoms. Research looking at NAC and PCOS focuses on three areas: insulin resistance, ovulatory function, and hormonal health.

NAC for insulin resistance

People with PCOS are at a higher risk of insulin resistance. This is when the body’s tissues are resistant to insulin, a hormone involved in blood glucose management. No matter their weight, up to 80% of people with PCOS have insulin resistance.

A small study of 37 people with PCOS found that those taking 1.8g of NAC daily for 5-6 weeks found improvements in insulin circulating levels and insulin sensitivity. It is important to note that people in larger bodies were given 3g of NAC.

People with PCOS tend to have high levels of circulating oxidative stress; this is linked to insulin resistance. NAC has been found to help reduce oxidative stress and insulin resistance in mice with PCOS. Of course, human studies are required to understand the true impact of NAC on oxidative stress and insulin resistance.

NAC for hirsutism

The current evidence suggests that NAC can be supportive of those with PCOS for conditions such as hirsutism associated with PCOS. Hirsutism is defined as excess hair growth on the face, chest and back in people assigned female at birth.

In fact, one study of 108 people with PCOS found that supplementing with NAC alongside clomiphene citrate (known as Clomid). Clomid is a popular fertility medication prescribed during fertility treatment. They found that supplementing with 1.8g of NAC per day with 100mg of Clomid significantly reduced hirsutism scores compared to those taking Metformin and Clomid.

NAC for ovulation and fertility

NAC has also been linked to improved fertility outcomes, by:

  • Increasing ovulation rates
  • Circulating oestrogen and progesterone levels
  • Endometrial thickness, therefore improving the likelihood of implantation of a fertilised egg

But, one research study of 573 people with PCOS found that NAC is only helpful when used alongside Clomifene Citrate (Clomid). The study above investigating NAC supplementation alongside Clomid found that this combination significantly increased ovulation and pregnancy rates in people with PCOS at a similar rate as Metformin.

Therefore, we require more research on the impact of NAC alone on ovulation and fertility outcomes in people with PCOS.

>> Read More | PCOS and Fertility: the ultimate guide to conception

It is important to note that the studies of NAC for PCOS are usually short-term and in small groups of participants. The long-term impact of NAC is unknown and more research is needed before definitive recommendations can be made.

Side effects of NAC

NAC supplements are not safe for everyone. We always recommend speaking with your medical provider before starting any supplements too.

Anyone who experiences the following should avoid taking NAC:

  • If you have a stomach or duodenal (small intestine) ulcer
  • Experiencing liver disease, or have in the past
  • Are allergic to acetylcysteine, or have had a reaction to NAC in the past
  • NAC may interfere with blood clotting therefore not advised for those with bleeding disorders or if you will be undergoing surgery in the near future

NAC also has some side effects, including:

  • Digestive problems such as diarrhoea, vomiting, and nausea
  • Dizziness
  • Dry mouth
  • A smell which some might find unpleasant

Where can I buy NAC supplements in the UK?

There are a number of NAC supplements available in the UK and worldwide. We have provided three options for you to decide which is best for you. 

NAC is available in capsule, tablet, and powder form.

Make sure to speak with your healthcare professional before taking NAC.

Troo NAC Supplement 600mg
£12.97 (£0.11 / count)

High-quality NAC supplement

  • One capsule contains 600mg of NAC
  • Vegan
  • 120 capsules
We earn a commission if you make a purchase, at no additional cost to you.
04/14/2024 10:15 pm GMT
N-Acetyl Cysteine (NAC) 600 mg 120 Capsules
£14.97 (£0.12 / count)

Swiss Bioenergetics food supplement adhering to GMP code of practice

  • One capsule contains 600mg of NAC
  • Manufactured in the UK
  • Suitable for vegans and vegetarians
We earn a commission if you make a purchase, at no additional cost to you.
04/14/2024 07:58 pm GMT
Bulk Pure N Acetyl L Cysteine (NAC) Powder
£44.99 £34.99 (£7.00 / 100 g)

A powder form NAC supplement

  • 1 scoop mixed with 50ml of water contains 700mg (0.7g) of NAC
  • Mix 1 scoop (approximately 700mg) with 50ml water
We earn a commission if you make a purchase, at no additional cost to you.
04/14/2024 07:17 pm GMT


Where can you get NAC from?

NAC is found in various foods. Including high-protein foods such as meat, fish, tofu, protein powder or some plant-based meat alternatives. It can also be found in lower amounts of eggs, whole grains, leafy green vegetables, and legumes.

However, the dose that may be helpful for PCOS symptoms is likely too high to obtain from food sources. Therefore a supplement might be appropriate. We have provided some supplements available in the UK at the end of the article.

Can I take Inositol and NAC together?

Most people with PCOS have heard of inositol. Understandably, you might be wondering if you could take inositol alongside NAC. 

Inositol and NAC have similar benefits in those with PCOS. Current research is not conclusive if there is a cumulative impact of taking both together versus supplementing with one only.

As NAC is linked to reducing blood sugar levels so taking inositol, another insulin sensitiser, alongside it may result in hypoglycemia. Hypoglycemia is when your blood sugar levels drop too low and cause symptoms like feeling extremely hungry, trembling or shakiness, and sweating.

Can I take metformin and NAC together?

There are no reported interactions between metformin and NAC. But, again, as it is an insulin sensitiser it may contribute to hypoglycemia if taken together.

Metformin is associated with depleted vitamin B12 levels. There are no known interactions between vitamin B12 supplements or injections and NAC supplements.

We always recommend speaking with your medical professional or pharmacist to assess your personal needs.

How much NAC should I take?

Within the research, the dose of NAC investigated is 1.8g to 3g per day. But the common dosage for supplementing is 600-1200mg (0.6-1.2g). There is no specific advice for NAC for PCOS dosage so stick to manufacturers’ guidelines and speak to your healthcare professional before starting a new supplement.

Key takeaways: NAC for PCOS

The research surrounding NAC for PCOS symptom management is promising and there is limited evidence supporting its impact on insulin resistance, hirsutism, ovulation and fertility outcomes. However, more high-quality evidence is required to conclusively recommend NAC for PCOS. Plus, you should be aware of the side effects and contraindications of NAC and speak to a healthcare professional if you are considering trying NAC for PCOS.

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Shannon Western ANutr Author at The PCOS Collective

Guest Author | Registered Associate Nutritionist

Shannon is a Registered Associate Nutritionist and Nutrition Counsellor. She is the founder of Ease Nutrition Therapy - a nutrition counselling clinic that specialises in weight-inclusive care. She has a huge passion for helping people recover from disordered eating. Shannon offers 1:1 PCOS support in our virtual PCOS clinic.

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