The idea that toothpaste can be used to treat spots has been around for years. But does it actually work – or could it make things worse?

“A spot happens when a sebaceous gland gets plugged and inflamed,” says Dr Rosalind Simpson, a consultant dermatologist and associate professor at the University of Nottingham. Acne develops through a combination of blocked pores, increased sebum production and changes in Cutibacterium acnes , bacteria that naturally live on the skin.

The thinking is that ingredients such as baking soda or alcohol can dry out a pimple, making it appear smaller. But that doesn’t mean toothpaste is good for skin.

“One or two of the ingredients can temporarily dry out the skin a little bit,” says Simpson.…