Fact: Absolutely not true!!! This would be funny if so many people didn't believe it. None of the ingredients in toothpaste can have a positive effect on acne or change a blemish once you have it, and actually it can make matters worse. The bacteria in your mouth are not related to the bacteria in your pores that cause acne (P. acne). And although the fluoride or sodium monofluorophosphate in your toothpaste can help fight bacteria in your mouth, on your skin it actually can cause pimples and redness in the areas with which it comes in contact. This is known as perioral dermatitis (Sources: Journal of the American Dental Association, September 2003, page 1165; Journal of the American Academy of Dermatology, June 1990, pages 1029 -1032; and Archives of Dermatology, June 1975, page 793). The other ingredients in toothpaste might offer minimal abrasive properties, but they provide nothing that a gentle rubbing with a washcloth doesn't provide far better.