[Suzanne 3FC]

We are frequently asked if diet patches work. Here is a good Q&A from Berkeley Wellness, University of California

Q: Can diet patches that you stick on your skin be as good as they claim? B.P., VIA THE INTERNET

A: No, not at all. In spite of heavy promotion on TV, on the Internet, and in a rising tide of spam (unsolicited emails), these products are ineffective and may be dangerous. Sold under such names as Diet Patch, TrimPatch, Hydro-Gel, and MyDiet-Patch, these transdermal patches usually contain Fucus vesiculosus, a brown seaweed also known as bladderwrack. The claim is that the iodine from the seaweed will stimulate the thyroid gland to boost your metabolism and thus burn more fat. Patches may also contain ingredients such as chromium, garcinia, and guarana, for which similar fat-burning claims are made.

Weight-loss products such as ephedra and its variants ordinarily evade the jurisdiction of the FDA because they are classified as "dietary supplements," which are largely unregulated. But the patches get caught on a technicality: they are not taken by mouth, so the FDA classifies them as drugs. As such, they are required to submit evidence of their safety and efficacy, and there is no such evidence. Excess iodine won’t lead to weight loss, though it could lead to thyroid disorders. Most professionals think these patches are about as bogus as bogus can get. The FDA has issued warning letters to several marketers, including TrimPatch, and has seized some products. But sales go on.

Ironically, the patches usually come with weight loss advice: cut calories, get more exercise. That’s what you should do to lose weight, but don’t waste your money or endanger your health with the patches.