Diet Supplements: Slim Pickings

Google "diet supplements" and you'll get about 26 million search results, most from companies selling products that promise to cure your weight problem--in as little as a week. If only it were so easy.
Their proprietary formulas, which can cost $40 a bottle and up, are often touted as "all natural," "healthy," and "proven to work" with "no side effects." Their names tell all: Fat Blaster, Slenderizer, MeltRX, NanoSlim, Size 0, and, for men coveting a slim, ripped body, TestoRipped and Man Scorch. If you're overwhelmed by all the products, there are even websites that promise to help clear the confusion--that is, sell you their own products.
But weight loss is neither quick nor easy. Nothing "melts fat away," and certain pills can have serious side effects. Dietary supplements do not have to be tested for safety or effectiveness, nor do they have to list warnings or contraindications. And the FDA can pull them from the market only after there's proven evidence of harm. That's what happened with ephedra, which the FDA finally banned in 2004--but only after serious problems and even deaths were reported. Since then, ephedra-like substances, including synephrine (in bitter orange) and dimethylamylamine (sometimes listed as geranium oil), have taken its place and may not be any safer.
More cause for alarm: Some diet supplements have been found to contain undeclared pharmaceuticals, which can be harmful if not used properly. In recent years, the FDA has warned about dozens of diet supplements, many from China, that were tainted with drugs, including amphetamine-like chemicals, tranquilizers, antidepressants, prescription diuretics, and anti-seizure medications.
Keep in mind that if a diet supplement does work, it's likely to have other effects that may not be so desirable. For example, if it boosts metabolism, it might also boost heart rate and blood pressure. Some ingredients (such as chaste tree, daidzein, and dong quai) can affect levels of some hormones. And diet aids, even if "natural," may interact with medications.
Bottom line: Don't expect dietary supplements to help you lose weight. At best, the evidence is slim for just a couple of them. If any product was really effective, drug companies would be testing and patenting their ingredients, and there would be many fewer overweight and obese people. As it is, prescription diet pills have had a lousy track record, too. And even if some diet supplements do cause you to lose a few pounds, none are proven to sustain weight loss.

-University of Berkeley Wellness Alerts