Kylie Jenner is known for her pillow lips, natural or not. The “Keeping Up With the Kardashians” star denies she has had plastic surgery on her famous pout, which has started an alarming new trend among young Twitter users.

The “Kylie Jenner Challenge” encourages people to put a glass or plastic cup on their lips and then suck for about five minutes. The pressure brings blood rushing to their lips and inflates them so they look just like the 17-year-old Jenner's.

Social media users have posted their pouts online, though many have done so in a mocking manner. Sure, in some cases lips will swell, but it’s a painful process that can lead to disastrous bruising.

Some of the results are scary:

More, the trend can cause severe injury. "The new trend in trying to DIY lip plumping is quite concerning," Dr. Dendy Engelman, a board certified dermatologic surgeon, told "Not only can significant pain, swelling and bruising result from these suction techniques, but there is potential risk for scarring and permanent disfigurement with repeated attempts."

Even though it seems evident to most people that Jenner’s lips are enhanced, she insists she’s au naturel. "These plastic surgery rumors hurt my feelings to be honest and are kinda insulting ... Just in case anyone forgot ... I'm 16,” she wrote on Twitter in the past.

“I'm like, ‘Stop talking about my lips,' " she told Grazia magazine last Tuesday. "I haven't had plastic surgery. I've never been under the knife. People flash back to pictures of me when I was 12 and say ‘Kylie's so different’ but how can I look the same from 12 to 18?”

For all the latest Kardashian drama, check out Season 10 of “Keeping Up With the Kardashians” on E! every Sunday at 9 p.m. EDT.

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