L-carnitine / L-acetyl-carnitine
Written by Fertility Decoded. Reviewed by D R, MS (OBG), FRM. Review date: 31 August 2026.
The verdict
Promising for sperm motility/morphology in men with idiopathic infertility, but few trials, high heterogeneity, low-quality evidence.
An amino-acid derivative marketed for sperm motility; a common ingredient in Indian OTC male-fertility products.
What the evidence shows
Systematic reviews (~8 RCTs vs. placebo): significant improvement in sperm concentration, total motility, forward motility, normal morphology, and pregnancy rate — but few trials, high heterogeneity, low-quality evidence overall. Most effective reported in severe idiopathic infertility.
Evidence tier
Non-Cochrane evidence🟡 Smaller systematic reviews/meta-analyses or RCTs exist, no Cochrane-grade synthesis. Emerging, not proven.
Frequently asked questions
- Reviews (~8 RCTs) report improvements in motility, morphology and pregnancy rate, mostly in severe idiopathic infertility — but few trials, high heterogeneity, low-quality evidence overall.
Does L-carnitine improve sperm motility?
Sources
Take this further
Sources last reviewed .