Is it true that toothpaste can treat pimples?

Toothpaste is being touted on social media as a hack to clear acne, soothe burns and whiten fingernails.

But dermatologists say products intended for these purposes are better options, and toothpaste may exacerbate skin conditions.

Toothpastes have many ingredients -- fluoride to help prevent cavities; baking soda; hydrogen peroxide; abrasives to help remove substances from teeth surfaces; flavors; sweeteners; foaming agents; and humectants to keep the toothpaste from crumbling.

Some of these can combat acne. Hydrogen peroxide, for instance, can dry out zits and help kill bacteria.

"It's understandable that people may have tried this as a home remedy, especially in the days before we had the better options for acne spot treatments," said Shadi Kourosh, director of the dermatology division of community health at Massachusetts General Hospital and associate professor at Harvard Medical School.

But because toothpaste is not formulated for the skin, it can lead to dryness, irritation and inflammation, potentially delaying the pimple-healing process or worsening acne. Inflammation increases the risk of post-inflammatory hyperpigmentation, Hadley King, a dermatologist, said.

Carol Cheng, assistant clinical professor of dermatology at UCLA, said she has seen patients who have used toothpaste as a salve to treat acne and developed a painful rash. "I've even seen a couple of cases of chemical burns because of the irritating properties from toothpaste that should not be used on the skin and left on for long periods of time," she said.

Toothpaste is also not recommended for other dermatologic conditions, particularly burns. While toothpaste may have a cooling effect, one study showed that it can worsen burns. Instead, keep the skin moist with petroleum jelly and, for more severe burns, seek medical attention, said Kevin Sharghi, assistant professor of dermatology at Johns Hopkins University School of Medicine.

And while toothpaste may help shine and whiten nails because of the abrasive properties in some brands that contain baking soda, for instance, it can cause irritation for those with skin allergies or sensitivities.

What else you should know:

There are over-the-counter products you can use for pimple prevention or treatment, according to the American Academy of Dermatology:

Adapalene, a retinoid, helps prevent clogged pores and reduces inflammation. It also regulates oil production, and treats and prevents pimples.Azelaic acid helps kill acne-causing bacteria and reduces the production of keratin, a protein that forms the outer layer of skin. Azelaic acid helps prevent the buildup of dead skin cells that can clog pores, contributing to acne.Benzoyl peroxide, an antibacterial agent, helps manage mild to moderate acne. Over-the-counter products may contain up to 10% benzoyl peroxide, but users should start with 2.5% to avoid unwanted side effects, including dryness and irritation, the AAD said.Salicylic acid exfoliates the skin and can reduce redness and swelling, and unclog pores, helping to control blackheads and whiteheads.

"These ingredients target acne-causing bacteria, inflammation and sebum production, allowing them to treat and prevent breakouts," Marisa Garshick, a dermatologist, said.

If over-the-counter products are not helping, she said, talk to a dermatologist about prescription options.

The bottom line

Toothpaste is not recommended for skin care. Instead, use over-the-counter or prescription medications that are intended to treat acne and other dermatologic conditions, dermatologists said.