Weight loss patches.
They sell really well on eBay, or at least they used to. Magic patches that you paste onto your body overnight that magically make you lose weight. Usually the magical properties are ascribed to a mystical blend of herbs that are contained in the patch, and of course, there are the before and after photos that show you all the gunk that has been drawn out of the body by the patch.
Of course, all this is is a combination of sweat and the now liquified herbal mixture.
The magical weight loss patch is, of course, total hokum. It buys into the established idea of stop-smoking patches, which can work when used correctly as part of a smoking cessation program. Of course, these replace nicotine, so that the smokers have a reduced nicotine craving.
The weight loss patches release no such chemicals into the body and do not allay appetitive (cravings) or remove any such toxins from the body. Ask the manufactures to list the exact chemical structure of the alleged toxins that these weight loss patches apparently removed. "Toxins" is just one of those marketing terms that go unsubstantiated.
The mystical blend of herbs is of such low concentration and quantity that any active dosing that may exist in them will be too weak to have any effect. Any effect they do have will be due to their placebo effect. And, weirdly, the more expensive the patches are, the greater their placebo effect will be.
So, in a weird kind of way, they might work…just not the way they tell you that they do.
Save your money. Buy better quality food instead and avoid the herbal, unregulated, weight loss patches.