TikTokers are using calamine lotion as makeup primer. Doctors say: Bad idea.

Women around the world are smearing calamine lotion all over their faces before applying makeup – a “beauty hack” that’s gone viral on TikTok that they say helps dry out oily skin, repair acne scars and keep their makeup in place for hours on end.

Some are using a sponge or a makeup brush to dab on the over-the-counter product commonly used to soothe rashes and other skin conditions that cause itching, such as chickenpox. Others wasted no time, pouring the pink lotion directly onto their face and rubbing it in with their bare hands before applying foundation and other makeup right on top of the thin crust.

“I cannot see my pores anywhere,” one TikToker said in approval, claiming the product made her skin appear “super matte.” Other beauty enthusiasts on the platform have hailed calamine as a primer – claiming it helps their makeup stay put in the summer sun and throughout 12-hour workdays.

TikTokers say they are “obsessed” with the discovery and the hashtag #calamineprimer has about 3.5 million views on the platform. But dermatologists and makeup experts are warning that those jumping on the trend could risk worsening skin conditions and longterm damage.

“It just doesn’t make sense to use calamine lotion and risk drying out the skin and damaging the skin barrier,” Azadeh Shirazi, a dermatologist practicing in the San Diego area, told The Washington Post.

Shirazi, who goes by the username “skinbydrazi” on TikTok, has tried to tackle the trend head-on, using her account to debunk beauty myths and trends. Shirazi said that in recent months users have tagged her in comments on such videos, asking her for medical advice.

Shirazi has used the platform to urge people to consider the ingredients before turning to calamine lotion as a primer, as overuse may lead to “severe irritation and worsening of scars.”

While experts say the lotion can be used to shrink acne lesions and marks left on the skin, especially as a targeted treatment, the American Academy of Dermatology warns that the astringent calamine can worsen skin irritations if not used sparingly.

“Calamine lotion is made up of zinc oxide, ferric oxide and phenol. Zinc oxide is an astringent that can help absorb excess oil and have a mattifying effect,” Shirazi said, adding that the product is generally recommended to treat oozing wounds from infections such as chickenpox and monkeypox. The lotion is also used to soothe insect bites, pimples, rashes and poison ivy.

The product, Shirazi says, causes the skin surface to dry up and harden, protecting it while it repairs. “Ferric oxide helps with itching and the phenol is also a powerful exfoliant,” she said. “Combining phenol with an astringent as in calamine lotion can be very drying and irritating, leading to a damaged skin barrier. It can worsen skin conditions such as acne, rosacea and dermatitis.”

On TikTok, Shirazi told her 1.8 million followers simply: “It’s a no from me.”