Some men are gritting their teeth and gulping down a few ounces of a citrus-flavored dietary supplement that the manufacturer says is "specifically designed to optimize sperm quality."
Besides the taste, there's the cost. The supplement, called proXeed, costs $500 for a six-month supply. But many men and their wives think it is worth it. The problem, according to urologist Larry L. Lipshultz, MD, is low-quality sperm.
That's why Lipshultz advises some patients to take proXeed, anover-the-counter product manufactured in Italy for a Maryland company. Lipshultz is the director of the first U.S. clinical trial for the dietary supplement. Researchers are eager to find out if it works as they gain more knowledge into the nature of male infertility.
"We need to raise awareness of male infertility," says Lipshultz, director of the proXeed study and head of the Division of Male Reproductive Medicine and Surgery at Baylor College of Medicine. He ticks off statistics from a 1998 government study: 1.1 million U.S. women per year make appointments with their gynecologists for infertility. Of those cases, only 20% of male partners, some 250,000 men, were referred for evaluations, he says.
The main ingredients in proXeed -- levocarnitine and acetyl-L-carnitine -- have been "around for a long time," Lipshultz says. The ingredients have been tested many times in Europe -- where they have been used for some 30 years -- and while the results were encouraging, the tests were poorly done, he says. ProXeed also is being tested at The Jones Institute of Reproductive Medicine at Eastern Virginia Medical School in Norfolk, Va., site of the nation's first in vitro fertilization procedure.
In healthy people, levocarnitine is responsible for carrying fats into cells and also is a source of fuel, according to proXeed's manufacturer. Fats are the major source of energy for sperm movement. Acetyl-L-carnitine, the firm says, is important for the development of cell membranes, another important component of sperm that allows them to fertilize the egg. ProXeed also contains fructose, a major energy-yielding substance in semen, and citric acid, a key intermediary in energy production, according to the company.
Talk to your doctor to see if proXeed might be right for you or your partner. As more evidence surfaces on the benefits -- and potential risks of the supplement -- doctors will feel more comfortable about whether to recommend the supplement as part of the overall treatment for male fertility problems.