Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us





Combination of selenium and NAC raises testosterone levels

A cocktail containing high doses of selenium and the amino acid N-acetyl-cysteine increases the sperm cell production and testosterone levels. Researchers at the Shahid Beheshti University in Iran discovered this after doing a trial with nearly five hundred men. Just how relevant the results are for well fed athletes or life extensionists in the affluent West we don't know.

The men were experiencing fertility problems. Doctors had already determined that they had a low sperm count or that they had low quality sperm cells.

Combination of selenium and NAC raises testosterone levels
The men were given a supplement to take daily for six months: 26 weeks. The placebo group were given a fake pill, the Se group took a daily dose of 200 micrograms of selenium, and the NAC group took 600 milligrams of N-acetyl-cysteine. The Se+NAC group took both supplements.

The supplements had a positive effect on the sperm quantity, motility and the number of sperm cells. The latter effect is shown in the graph below.

Combination of selenium and NAC raises testosterone levels

The supplements also reduced the number of subnormal sperm cells. The magnitude of the effects was approximately the same: the graphs are almost identical.

The researchers also noticed an effect on the testosterone level. After taking the supplements for six months, the placebo group had a testosterone level of 17.4 nanomols per litre. In the Se and the NAC groups the level had risen to 20.1 nanomols per litre, and in the Se+NAC group it was 20.9 nanomols per litre. See the graph below.

Combination of selenium and NAC raises testosterone levels

The FSH and LH levels, on the other hand, went down. The menís pituitary glands apparently reacted to the rise in testosterone level by becoming less active.

The researchers think that the supplements may have an antioxidant effect in the testes. Selenium is needed for the detoxifying enzyme glutathione peroxidase. This is an enzyme that renders peroxides harmless. NAC is a precursor of the detoxifying enzyme glutathione.

J Urol. 2009 Feb;181(2):741-51.

Mucuna pruriens: more testosterone, more LH, less prolactin 19.11.2008
More magnesium, more free testosterone 11.11.2008
Animal study: pomegranate juice increases testosterone level and sperm quality 02.10.2008