Randomized, triple-blind, placebo-controlled clinical trial examining the effects of alpha-lipoic acid supplement on the spermatogram and seminal oxidative stress in infertile men

Fertil Steril. 2015 Aug;104(2):318-24. doi: 10.1016/j.fertnstert.2015.05.014. Epub 2015 Jun 11.


Objective: To evaluate effects of supplementation with alpha-lipoic acid (ALA) on the spermatogram and seminal oxidative stress biomarkers.

Design: Randomized, triple-blind, placebo-controlled clinical trial.

Setting: Infertility clinic.

Patient(s): Infertile men.

Intervention(s): ALA (600 mg) or placebo for 12 weeks.

Main outcome measure(s): Semen analysis, anthropometric, dietary, and physical activity assessments, total antioxidant capacity, and malondialdehyde.

Result(s): At the end of study, the total sperm count, sperm concentration, and motility in the intervention group were significantly higher than in the control group. In the ALA group, the total sperm count, sperm concentration, and motility levels were also significantly increased at the end of study compared with baseline values. However, there were no significant differences in ejaculate volume, normal morphology percentage, and live sperm between groups. ALA supplementation also resulted in a significant improvement in seminal levels of total antioxidant capacity (TAC) and malondialdehyde compared with the placebo.

Conclusion(s): According to the results, medical therapy of asthenoteratospermia with ALA supplement could improve quality of semen parameters. However, further investigation is suggested in this regard.

Clinical trial registration number: IRCT2013111010181N3.

Keywords: Alpha-lipoic acid; asthenospermia; infertile men; oxidative stress; spermatogram.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Humans
  • Infertility, Male / diagnosis
  • Infertility, Male / drug therapy*
  • Male
  • Oxidative Stress / drug effects*
  • Oxidative Stress / physiology
  • Semen / drug effects*
  • Semen / physiology
  • Sperm Count / methods
  • Sperm Motility / drug effects*
  • Sperm Motility / physiology
  • Thioctic Acid / administration & dosage*


  • Thioctic Acid

Associated data

  • IRCT/IRCT2013111010181N3