New evidence
A meta-analysis linked NAC to a 9.7 percentage-point improvement in sperm motility — but the data come from clinical studies in infertile men, not the general population.
This is the first strong evidence that NAC can improve semen quality in men with fertility issues, but it’s a single meta-analysis on a clinical population — so healthy men shouldn’t rush to supplement based on this alone.
Researchers pooled data from multiple trials and found that infertile men who took NAC saw a statistically meaningful increase in total sperm motility (about 9.7 percentage points) and also improved sperm volume, concentration, and shape — with no reported side effects. Because the studies focused on men with diagnosed infertility, it’s not yet known whether these benefits would extend to men with normal semen parameters.
Where this fits in the evidence
This is among the first studies we've indexed on N-Acetyl Cysteine for Improved Total Sperm Motility — treat it as an early signal until more research accumulates.
The study
- Meta-Analysis
- 2025-03-24
- Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.