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Evaluation of monotherapy of Coenzyme Q10, L-carnitine or combined therapy on semen parameters in idiopathic male infertility: A placebo-controlled double blind randomized clinical trial

Ahmed Higazy, Waleed Mohammed, M Esmat, Mohamed Samir
Arab Journal of Urology 2025 24(1):68-74

Bibliography

PubMed
PMID 41509099
PubMed Central
PMC12777869
DOI
10.1080/20905998.2025.2509424
Funding
No specific external funding statement was identified in the accessible full-text record.
Competing interests
The authors reported no potential conflict of interest.

Study snapshot

DesignFour-arm randomized placebo-controlled double-blind clinical trial; sealed-envelope allocation prepared by an independent third party; patients, data collectors and statistician blinded.
ModelMen with idiopathic oligoasthenoteratozoospermia (OAT).
Sample200 randomized equally; 174 completed: CoQ10 n=43, L-carnitine n=42, combination n=44, placebo n=45.
InterventionCoQ10 200 mg/day, L-carnitine 1 g/day, CoQ10 200 mg/day + L-carnitine 1 g/day, or placebo.
Duration3 months.
EndpointsSemen volume; Sperm concentration; Progressive and total motility; Morphology; Sperm DNA fragmentation index; Testosterone; FSH; LH; Prolactin

What the study showed, in plain terms

This four-arm trial randomized 200 men with idiopathic OAT to CoQ10, L-carnitine, their combination, or placebo for three months. Allocation used sealed envelopes prepared by a third party, and patients, data collectors and the statistician were blinded.

Among 174 completers, CoQ10 monotherapy increased sperm concentration from 13.42 ± 2.95 to 26.86 ± 7.86 million/mL (p=0.001). Active monotherapy and combination groups also improved motility, morphology and sperm-DNA-fragmentation measures, whereas placebo did not show comparable improvement. The combination generally produced the largest changes.

Testosterone rose and FSH/LH fell in the active groups, while prolactin remained essentially unchanged. These are semen-quality, DNA-fragmentation and hormonal outcomes; the trial did not test conception, pregnancy or live birth.

Key findings

  • CoQ10 monotherapy: sperm concentration increased from 13.42 ± 2.95 to 26.86 ± 7.86 million/mL (p=0.001).
  • Active regimens improved sperm concentration, motility, morphology and sperm-DNA-fragmentation measures; placebo showed no comparable change.
  • Combination therapy generally produced larger semen-parameter improvements than either monotherapy, but this cannot be attributed to CoQ10 alone.
  • CoQ10 monotherapy increased testosterone from 3.98 ± 0.91 to 5.73 ± 1.32, reduced FSH from 8.50 ± 1.96 to 6.41 ± 1.48, and reduced LH from 8.07 ± 2.21 to 5.24 ± 1.21; prolactin did not materially change.
  • Twenty-six of 200 randomized participants did not complete the three-month evaluation; 174 were included in the final analysis.

What this study can and cannot tell us

  • Outcomes were semen parameters and sperm DNA fragmentation, not pregnancy or live birth; improved semen quality is not proof of improved live-birth probability.
  • The published analysis focused on 174 completers from 200 randomized participants, creating attrition-related uncertainty.
  • Combination-arm superiority reflects two active agents and cannot identify the independent contribution of CoQ10.
  • Single-center, three-month study in idiopathic OAT; findings should not be generalized to every cause of male infertility.

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