But the same doctors who plan to experiment with the product, called proXeed, warn that there's no proof yet that it works - and are urging Americans to see a doctor before trying it on their own. There are many causes of male infertility, occasionally life-threatening ones, that proXeed can't help but that regular medicine can. Other options such as in vitro fertilization can cost thousands. Up to 40 percent of conception difficulties are believed caused, at least partly, by poor sperm. ProXeed contains two types of L-carnitine, a compound naturally present in the body important for cellular metabolism.
People absorb L-carnitine mostly from red meat and dairy products.
Small European studies suggest taking specific amounts of L-carnitine and a metabolite, acetylcarnitine, for three to six months gave subfertile men more normal sperm. It won't create super fertility. He will perform the first U.S. study this summer, giving up to 80 men at his clinic and Brown University either proXeed or a dummy pill. Doctors are reassured about trying proXeed because the Food and Drug Administration says the prescription L-carnitine that treats metabolic disease has proved safe. But L-carnitine also is sold as a dietary supplement, and dietary supplements are largely unregulated.