Kylie Jenner has urged fans not to copy her look

After photographs of fans with severely swollen lips began to flood the site, Kylie wrote: "I'm not here to try & encourage people/young girls to look like me or to think this is the way they should look.

"I want to encourage people/young girls like me to be YOURSELF & not be afraid to experiment w your look."

It is said the brunette beauty has been left "mortified" by the challenge, which saw some Twitter users place their mouths inside a bottle and then suck out the air to increase the size of their lips through bruising and swelling.

A source told HollywoodLife.com: "Kylie is mortified that some people are trying to plump their lips to look like her. That wasn't her intention. She's not trying to be the poster child for full lips and she's absolutely saddened by this entire ordeal.

"She wishes she could meet every single person who's done this crazy thing face-to-face, and tell them they're beautiful just the way they are. Kylie's not trying to be a trendsetter by any means with her lips. She had no idea some people would go to these very dangerous lengths in an attempt to make their lips fuller. She wants it to stop and believes all beauty comes from within."

Kylie's appearance has recently come under much scrutiny with her increasingly fuller lips prompting speculation she has undergone cosmetic surgery, a claim which the 'Keeping Up With The Kardashians' star has denied.

She previously said: "I'm like, 'Stop talking about my lips.' I haven't had plastic surgery. I've never been under the knife.

"People flashback 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?"