The role of N-acetyl-cysteine (NAC) orally daily on the sperm parameters and serum hormones in idiopathic infertile men: A systematic review and meta-analysis of randomised controlled trials

The meta-analysis was performed to access the role of N-acetyl-cysteine (NAC) orally daily on the sperm parameters and serum hormones in idiopathic infertile men. Randomised controlled trials (RCTs) were retrieved using PubMed, EMBASE and Cochrane register databases. The references of included studies were also searched. Finally, three articles including 431 infertile men were analysed. The results indicated that the NAC group had a considerable improvement in sperm concentration (mean difference MD], 3.80; p < .00001), ejaculate volume (MD, 0.69; p = .002), sperm motility (MD, 4.69; p < .0001) and normal morphology (MD, 1.68; p = .0002) compared with the placebo group. However, in terms of serum hormones, the NAC group did not show significant difference in increasing the serum levels of testosterone (MD, 1.35; p = .21), luteinising hormone (MD, 0.82; p = .40), follicle-stimulating hormone (MD, −7.48; p = .29) and prolactin (MD, −0.34; p = .32) compared with the placebo group. In conclusion, NAC orally daily produced a greater improvement in sperm concentration, ejaculate volume, sperm motility and normal morphology for idiopathic infertile men, whereas no significant influence in serum hormones, which required more high-quality RCTs with sufficient sample sizes and statistics to prove.