Health experts are not happy with the Burner Balm, the weight loss lip balm, saying it's a gimmick.
The manufacturers of the product, which hit the shops in the US six months ago, say four key ingredients blended together make it work: Green tea, caffeine, the mineral Chromium Piclinate - (which, it's claimed, helps the body burn fat), and the herb Hoodia (which apparently suppresses the appetite), reports The BBC.
The Burner Balm website states the contents "have all been proven for many years to be effective as dietary supplements".
But experts have hit back, saying it's a gimmick.
Tam Fry, from the National Obesity Forum in London, told Newsbeat: "My main concern is young women because they're easily influenced by their peers.
"You would have to put this on your lips every minute of the day to get enough to have any effect whatsoever.
"The only answer to losing weight is eating healthily and exercise."
The makers of the lippy claim the contents of the lip balm quickly dissolve through the lips and into the bloodstream so users don't even have to lick their lips for the ingredients to kick in. Consumers are advised to apply it no more than four to six times a day.
Currently, there's no evidence that the balm works but the makers say they're putting together a scientific study which proves it does.
Matt Mills, the inventor, said: "This is not a gimmick. It's a low cost dietary product that people want and that's being proven everyday."