N-acetylcysteine (NAC)
Written by Fertility Decoded. Reviewed by D R, MS (OBG), FRM. Review date: 31 August 2026.
The verdict
Mixed results as an add-on to standard PCOS ovulation induction; not reliably effective across trials.
An antioxidant/amino-acid derivative, commonly added to clomiphene citrate for PCOS patients who don't respond to clomiphene alone.
What the evidence shows
Evidence is genuinely mixed: several trials report improved ovulation/pregnancy rates as an adjuvant to clomiphene in clomiphene-resistant PCOS; at least one RCT found no significant difference in follicle count, endometrial thickness, or pregnancy rate. No Cochrane-graded synthesis specific to this use identified.
Evidence tier
Very limited evidence⚪ A handful of small trials, often single-source or industry-funded, not independently replicated.
Frequently asked questions
- Mixed — several trials report better ovulation/pregnancy as an add-on to clomiphene in clomiphene-resistant PCOS; at least one found no difference. Not reliably effective.
- There's no Cochrane-graded dose for this use; decide it with your doctor as an adjuvant, not by self-prescribing.
Does NAC help PCOS ovulation?
What dose of NAC for PCOS?
Sources
Take this further
Sources last reviewed .