Zinc is required for the production of testosterone. If you have a zinc deficiency, taking a supplement may improve your libido and energy. If your zinc levels are adequate, zinc will probably have no effect.

Oysters are one of the best food sources of zinc, although gooeys probably have other chemical compounds that increase the sex drive. Pumpkin seeds are another food that are rich in zinc.

The U.S. recommeded daily value for zinc is 15 milligrams. This amount is considered to be the average amount needed for good health (according to the conservative estimates of the US Government). There is abundant research that concludes that men require more zinc than women, and that physically active people need more than couch potatos. Individual need may also vary - those with gastrointestinal conditions may not absorb enough zinc even if the diet is balanced. Body weight is another consideration - a tall, muscular indivdual would generally need more than average.

Fortunately, zinc is not expensive - a daily dose costs just a few cents. The most common strength of a zinc supplement is 30 milligrams. Those who weigh more or are very active physically might consider 50 mg, while cautious individuals might go for a 15 mg supplement.

The Research

There are dozens of studies showing that low zinc levels depress testosterone - that is generally accepted as fact. What is not clear is how many men have a zinc deficiency great enough to depress their testosterone.

A 2006 study found that elite athletes (wrestlers) who engaged in exhausting exercise had low levels of thyroid hormone and testosterone, but a zinc supplement (3 mg oral zinc sulfate/kg/day) raised hormone levels. PMID:16648789 This dose is somewhat high - for a 150 lb male (70 kilos) it would be 210 milligrams per day.

Low Zinc levels have been cited as a factor in male infertility in dozens of studies. Zinc can often increase sperm count, sperm motility and sperm and ejaculate volume in men with sub-optimal ferility.

Zinc can be toxic if too large a dose is consumed. Nausea and stomach upset are the most obvious symptoms of too large a dose, although long term accumulation can be more subtle. An active adult should probably not take more than 30 to 50 mg of zinc daily on a long term basis.

While zinc is zinc, the form of a supplement may affect how much of the metal crosses into the blood and becomes biologically active. In one study on bulls, a chelated form (zinc propionate) was more active than the inorganic form (zinc sulfate). Better zinc supplements are chelated, and do not contain the sulfate or oxide forms.