Coenzyme Q10 (also known as ubiquinone is a compound found naturally in nearly every cell in the human body. CoQ10 is a fat-soluble substance, whose primary role is as a vital intermediate of the electron transport system in the mitochondria. Adequate amounts of CoQ10 are necessary for cellular respiration and ATP production. CoQ10 also functions as an intercellular antioxidant. Recently, many studies have been performed to investigate whether supplementing infertile men with antioxidants can improve seminal parameters. Among the various antioxidants tested, CoQ10 appears to play an important role in energy metabolism, as well as functioning as a liposoluble chain-breaking antioxidant for cell membranes and lipoproteins.

The following are brief descriptions of few key publications on the subject.

1.     REVIEW: A SYSTEMATIC REVIEW AND META-ANALYSIS

The aim of this study was to evaluate the effect of coenzyme Q10 treatments in male infertility. Three trials were included: 149 males in CoQ10 group and 147 males in placebo group. The results of this meta-analysis show that supplementing infertile men with CoQ10 does not increase pregnancy rates. The analysis showed, among patients receiving CoQ10 treatment, a statistically significant increase in CoQ10 seminal concentration, sperm concentration and sperm motility. In brief, there is no evidence in the literature that CoQ10 increases either live birth or pregnancy rates, but there is a global improvement in sperm parameters.

Reference: Rafael Lafuente et al. Coenzyme Q10 and male infertility: a meta- analysis J Assist Reprod Genet (2013) 30:1147–1156

2.     CLINICAL: PLACEBO-CONTROLLED, DOUBLE-BLIND RANDOMIZED TRIAL

This trial is to evaluate the effectiveness of coenzyme Q10 treatment in improving semen quality in men with idiopathic infertility. Sixty infertile patients with sperm concentration >20 /mL, sperm forward motility <50%, and normal sperm morphology

>30. Patients underwent double-blind therapy with CoQ10, 200 mg/day, or placebo; the study design was one month of run-in, six months of therapy or placebo, and three months of follow-up. It has been found that Coenzyme Q10 and ubiquinol increased significantly in both seminal plasma and sperm cells after treatment, as well as spermatozoa motility. Patients with a lower baseline value of motility and levels of coenzyme Q10 had a statistically significant higher probability to be responders to the treatment. Authors concluded that the administration of coenzyme Q10 increases the level of the sperms and ubiquinol in semen and is effective in improving sperm kinetic features in patients affected by idiopathic asthenozoospermia.

Reference: Balercia et al. Coenzyme Q10 treatment in infertile men with idiopathic asthenozoospermia: a placebo-controlled, double-blind randomized trial. Fertil Steril 2009;91 :1785–92. 2009 by American Society for Reproductive Medicine

3.     CLINICAL: RANDOMISED, PLACEBO-CONTROLLED STUDY

This study examined the effect of CoQ10 on catalase, superoxide dismutase (SOD) and F2-isoprostanes in seminal plasma in infertile men and their relationship with CoQ10 level. Sixty infertile men with idiopathic oligoasthenoteratozoospermia (OAT) were randomised to receive 200 mg/day of CoQ10 or placebo for 3 months. CoQ10 group had higher catalase and SOD activity than the placebo group. There was a significant positive correlation between CoQ10 concentration and normal sperm morphology, catalase and SOD. Significant difference was shown between the mean of changes in seminal plasma 8-isoprostane in two groups after supplementation. Authors concluded that 3-month supplementation with CoQ10 can decrease oxidative stress in seminal plasma and improve semen parameters and antioxidant enzymes activity.

Reference: Nadjarzadeh A, et al. Effect of coenzyme Q10 supplementation on

antioxidant enzymes activity and oxidative stress of seminal plasma: a double‐ blind randomized clinical trial. Andrologia 2013, xx, 1–7.

4.     CLINICAL

The study to determine the efficacy of CoQ10 supplementation on semen parameters, sperm function and reproductive hormone profiles. A total of 212 infertile men with idiopathic oligoasthenoteratospermia were randomly assigned to receive 300 mg CoQ10 daily or a similar placebo regimen, during a 26-week period, followed by a 30- week treatment-free phase. Two semen analysis, acrosome reaction test, immunobead test for anti sperm antibody, and determination of resting levels of luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone and inhibin B were done in all participants. Significant improvement in sperm density and motility was evident with coenzyme Q10 therapy. Sperm morphology evaluation revealed an increase in the percent of normal forms in the coenzyme Q10 group. A positive correlation was found between treatment duration with coenzyme Q10 and sperm count as well as with sperm motility and sperm morphology. The coenzyme Q10 group had a significant decrease in serum follicle stimulating hormone and luteinizing hormone at the 26-week treatment phase. Workers concluded that CoQ10 supplementation resulted in a significant improvement in certain semen parameters.

Reference: Safarinejad MR. Efficacy of coenzyme Q10 on semen parameters,

sperm function and reproductive hormones in infertile men. J Urol 2009;