N-Acetyl Cysteine (NAC) for Sperm Quality

Typical dose

Recommended dose

600mg/day

Expected timeframe

3-6 months

Protocol

form

N-acetylcysteine capsules, sometimes combined with selenium in the trials

duration

Any trial would need at least 3 months, since spermatogenesis takes roughly 74 days plus epididymal transit

co factor

Evidence is insufficient. Small randomised and uncontrolled studies in men with infertility, typically using 600 mg NAC daily for three to six months and sometimes combined with selenium, have reported improvements in sperm concentration, motility and morphology, and reductions in seminal oxidative stress and DNA fragmentation. The rationale is coherent - spermatozoa are unusually vulnerable to oxidative damage because their membranes are rich in polyunsaturated fatty acids and they carry minimal cytoplasmic antioxidant capacity. But the trials are small, heterogeneous in population and dose, often of poor methodological quality, and Cochrane reviews of antioxidants for male subfertility find the evidence for live birth - the outcome that matters - to be of very low certainty.

titration

Not applicable given the evidence

starting dose

Not established. Trials used 600 mg/day, generally for at least three months

What the studies say

Less likely to help if