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
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
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