Pink lips are shown.Remember when kids would put two Pringles together to make duck lips? We’re well past that now.

There is a new fad that can be viewed via the hashtag #KylieJennerChallenge. It features pictures and videos of teens using shot glasses and bottles to create a vacuum around their mouth.

The vacuum suctions their lips until they are swollen in order to make them more pouty and full, just like the lips of the “Keeping Up With the Kardashians” star.

Many of the photos and videos of this fad populating the internet are epic fails, which many parents hope will provide a strong visual deterrent to their kids.

However, this fad isn’t harmless. Plastic surgeons, dermatologists and other physicians have issued warnings against this trend because participants risk lacerations, pain, bruising and permanent disfigurement.

“This fad is not a good idea—no part of this makes any physiological sense,” said Robert Mann, MD, who heads the craniofacial surgery division at Spectrum Health Helen DeVos Children’s Hospital and has reconstructed more than a thousand lips for birth defects and various injuries.

Dr. Mann said the kids taking the challenge are causing internal swelling and bruising, which could cause some long-term lip contour issues.

“Lips should be left alone unless there is a medical reason to intervene,” he said. “This could be a dangerous fad because people don’t realize that lips are actually very fragile. They are very susceptible to permanent damage. If you injure a lip, it is very difficult to achieve a normal contour due to irregular swelling that can lead to long-term unevenness. I can’t imagine risking a nice smile for a fad like this.”