Selenium is an essential mineral in the human body for its anti-oxidant properties.

There has been some research supporting its positive interaction with testosterone (1).

However, the impact is not significant.

Here is the abstract from the study:

Purpose

We explored the efficacy of selenium and/or or N-acetyl-cysteine for improving semen parameters in infertile men, and the associations among semen quality and the concentrations of selenium and N-acetyl-cysteine in seminal plasma.

Materials and Methods

The study included 468 infertile men with idiopathic oligo-asthenoteratospermia who were randomized to receive 200 μg selenium orally daily (selenium group of 116), 600 mg N-acetyl-cysteine orally daily (N-acetyl-cysteine group of 118), 200 μg selenium plus 600 mg N-acetyl-cysteine orally daily (selenium plus N-acetyl-cysteine group of 116) or similar regimen of placebo (control group of 118) for 26 weeks, followed by a 30-week treatment-free period.

These patients provided blood samples for the measurement of serum testosterone, estradiol, follicle-stimulating hormone, luteinizing hormone, prolactin, inhibin B, selenium and N-acetyl-cysteine.

Semen samples were also obtained for routine semen analysis, and the measurement of seminal plasma selenium and N-acetyl-cysteine.

Results

In response to selenium and N-acetyl-cysteine treatment serum follicle-stimulating hormone decreased but serum testosterone and inhibin B increased.

All semen parameters significantly improved with selenium and N-acetyl-cysteine treatment.

Administering selenium plus N-acetyl-cysteine resulted in additive beneficial effects.

A significant positive correlation existed between the seminal plasma concentrations of selenium and N-acetyl-cysteine, and semen parameters.

A strong correlation was observed between the sum of the selenium and N-acetyl-cysteine concentrations, and mean sperm concentration (r = 0.67, p = 0.01), sperm motility (r = 0.64, p = 0.01) and percent normal morphology (r = 0.66, p = 0.01).

Conclusions

These results indicate that supplemental selenium and N-acetyl-cysteine improve semen quality.

We advocate their use for male infertility treatment.