NAC and PCOS: How N-Acetylcysteine Can Benefit Women with PCOS

Polycystic Ovary Syndrome (PCOS) is a common hormonal disorder among women of reproductive age. N-Acetylcysteine (NAC), a dietary supplement known for its antioxidant properties, is emerging as a topic of research interest for women with PCOS (PMOS), particularly in relation to insulin sensitivity, hormonal balance and ovulation.

An important update: On 12 May 2026, an international consensus published in The Lancet renamed Polycystic Ovary Syndrome (PCOS) to Polyendocrine Metabolic Ovarian Syndrome (PMOS). The new name reflects the condition's wider metabolic effects, including oxidative stress and insulin resistance, both of which are central to the research on NAC discussed in this article. Both names will be used during the transition to the 2028 ICD update. Read our explainer on what the rename means for your hormones and fertility.

Understanding PCOS (PMOS)

Polycystic Ovary Syndrome (PCOS), now also referred to as Polyendocrine Metabolic Ovarian Syndrome (PMOS), is characterised by hormonal imbalance, irregular periods and in many cases the presence of multiple small follicles on the ovaries. It is one of the most common causes of fertility difficulties, affecting around 1 in 10 women of reproductive age in the UK.

Oxidative stress, insulin resistance and chronic low-grade inflammation are all associated with PCOS (PMOS) and are thought to contribute to its hormonal and reproductive effects. NAC addresses several of these mechanisms, which is why it has attracted growing research interest in this population.

The role of NAC as an antioxidant

NAC is a precursor to glutathione, the body's primary endogenous antioxidant. By supporting glutathione production, NAC may help reduce oxidative stress, which is elevated in women with PCOS (PMOS) and is thought to contribute to hormonal disruption, impaired ovulation and reduced egg quality.

A 2021 review published in Cureus highlighted oxidative stress as a key driver of PCOS pathology and identified antioxidant supplementation, including NAC, as a potential therapeutic approach worth further investigation.^[1]

NAC and insulin resistance in PCOS (PMOS)

Insulin resistance is present in the majority of women with PCOS (PMOS) and is now central to the condition's new name. Research suggests NAC may support improved insulin sensitivity, potentially by reducing oxidative damage to insulin signalling pathways. A study published in the Journal of Clinical Endocrinology and Metabolism found that NAC supplementation improved insulin sensitivity in women with PCOS compared to placebo, though the authors noted that larger trials are needed to confirm these findings.^[2]

NAC and hormonal balance in PCOS (PMOS)

PCOS (PMOS) is associated with elevated androgen levels, which may contribute to symptoms such as irregular cycles, acne and hirsutism. Some studies suggest NAC may support a reduction in androgen levels and help restore hormonal balance, potentially through its effects on insulin signalling and oxidative stress, though the evidence is not yet conclusive and individual responses vary.^[1][2]

NAC and fertility in PCOS (PMOS)

Irregular or absent ovulation is one of the primary fertility challenges associated with PCOS (PMOS). Research suggests NAC may support more regular ovulation and may also improve outcomes when used alongside fertility treatments. A randomised controlled trial published in Fertility and Sterility found that NAC used as an adjunct to clomiphene citrate improved ovulation and pregnancy rates in clomiphene-resistant women with PCOS compared to clomiphene alone.^[3] More research is needed to establish optimal dosing and timing.

Dietary sources of cysteine

NAC is not found directly in foods, but it is a supplement form of the amino acid cysteine, which can be obtained from dietary sources. Foods that provide cysteine include:

• Poultry: Chicken and turkey are good sources of cysteine.
• Pork: Also contains meaningful amounts of cysteine.
• Dairy and eggs: Yoghurt, cheese and eggs are rich in cysteine.
• Legumes: Lentils, chickpeas and soybeans are good plant-based sources.
• Seeds and nuts: Sunflower seeds and almonds provide cysteine.
• Whole grains: Oats and wheat germ are useful sources.

Dietary cysteine provides a background level of support, but the doses used in PCOS research (typically 600mg per day or more) are not achievable through diet alone, which is why supplementation is generally the practical route for women looking to use NAC for PCOS (PMOS) management.

Further reading on PCOS (PMOS)

• Myo-inositol and folate for PCOS (PMOS) — evidence-based support for insulin sensitivity and ovulation
• Folate, vitamin D and PCOS (PMOS) — why bioavailable folate and vitamin D matter for women with PCOS
• PCOS (PMOS) and intermittent fasting — dietary approaches for managing insulin resistance
• PCOS (PMOS) and egg quality — how oxidative stress may affect egg development
• Free webinar: low-grade inflammation and fertility — how oxidative stress and inflammation may affect PCOS and fertility
• PCOS has been renamed PMOS — what the new name means for your hormones and fertility

FAQs: NAC and PCOS (PMOS)

What is NAC and why is it relevant to PCOS (PMOS)?

NAC (N-Acetylcysteine) is a precursor to glutathione, the body's primary antioxidant. It is relevant to PCOS (PMOS) because oxidative stress and insulin resistance are both associated with the condition, and research suggests NAC may help address both of these mechanisms.

How much NAC should I take for PCOS (PMOS)?

The doses used in PCOS research typically range from 600mg to 1800mg per day. Zita West NAC provides 600mg per serving (two capsules). Always consult a healthcare provider before starting any new supplement, particularly at higher doses.

Can I take NAC alongside other PCOS supplements?

Yes. NAC is generally considered compatible with other PCOS-relevant supplements including inositol, folate, omega-3 and vitamin D. The Zita West PCOS Support Pack includes NAC alongside these other nutrients in a single formulation. Always inform your healthcare provider of any supplements you are taking.

Is NAC safe for women trying to conceive with PCOS (PMOS)?

NAC is generally considered safe at the doses used in research. However, as with any supplement when trying to conceive, it is important to discuss use with a healthcare provider or fertility specialist to ensure it is appropriate for your individual situation.

What is the difference between PCOS and PMOS?

PMOS (Polyendocrine Metabolic Ovarian Syndrome) is the new name for PCOS, adopted following an international consensus published in The Lancet in May 2026. The condition is the same but the new name better reflects its wider hormonal and metabolic effects. Read our full explainer on the rename.

References

1. Sandhu JK et al. (2021). Oxidative stress in polycystic ovarian syndrome and the effect of antioxidant N-Acetylcysteine on ovulation and pregnancy rate. Cureus. PubMed
2. Fulghesu AM et al. (2002). The effect of N-acetyl-cysteine on insulin secretion and sensitivity in PCOS patients. Journal of Clinical Endocrinology and Metabolism. PubMed
3. Elnashar A et al. (2007). N-acetyl cysteine vs metformin in treatment of clomiphene citrate-resistant PCOS. Fertility and Sterility. PubMed

External references: NHS: Polycystic ovary syndrome (PCOS)  |  The Lancet: PMOS consensus 2026

This content is for educational purposes only and is not intended to diagnose, treat, or replace medical advice. Always consult your healthcare provider before starting any new supplement, particularly if you have a hormonal condition such as PCOS (PMOS).