The Lowdown on Weight-Loss Supplements

Now that the holiday cookies are history, you've resolved to get fit and trim. Perhaps you've even considered taking over-the-counter dietary supplements to help you reach your weight-loss goals.

Drugstores, nutrition shops and Web sites offer a plethora of supplements and combination products that claim to help burn fat, block fat absorption, modulate carbohydrate metabolism, boost energy expenditure, suppress appetite, flush out excess water weight and control cravings - all good outcomes to an eager dieter.

So what's the harm in grabbing a bottle?

"There's a tremendous appeal for a magic pill to help lose weight - manufacturers of weight-loss pills appeal to that, I think," said Dr. Robert Saper, director of integrative medicine in the Department of Family Medicine at Boston University Medical Center.

But in a review of the scientific evidence, published in the Nov. 1, 2004, issue of American Family Physician, Saper suggested there's no miracle pill on the market. In fact, some of the supplements out there may be dangerous or might interact with prescription medications that people are taking, he said.

"There's very few of them that show benefit for what people are taking them for," agreed Dr. Gary A. Green, a clinical professor in the Division of Sports Medicine at the University of California, Los Angeles.

Steven Dentali, vice president of scientific and technical affairs at the American Herbal Products Association, offers a somewhat more upbeat assessment: "I would say there is some preliminary evidence that some of these ingredients can be useful in combination with diet and exercise."

Dietary supplements have quite a following among many Americans. Overall, 7 percent of adults use over-the-counter weight-loss supplements, according to a five-state survey reported in 2001 in the Journal of the American Medical Association. The use of nonprescription weight-loss products is particularly common among young obese women - 28.4 percent reported taking them.

One recent success story is that of former Playboy "Playmate of the Year" Anna Nicole Smith. The 37-year-old actress and model dropped 69 pounds in eight months using a formulation of TRIMSPA, a popular brand-name product, the supplement maker's Web site claims.

But do you know what you're getting when you buy brand-name dietary supplements, including TRIMSPA, Xenedrine, and Hydroxycut, or individual herbal products?

The Natural Medicines Comprehensive Database, a source for evidence-based information on natural brand-name products and ingredients, lists more than 50 individual supplements and 125 proprietary products, according to Saper, who examined individual ingredients found in several commercial products.