Kylie Jenner has warned fans that knock-offs of her cosmetics line being sold online may be dangerous - even causing infection and causing lips to stick together.
The reality star told fans on Snapchat not to buy the fake products because they contain contained "really, really dangerous" ingredients.
She insisted the only place customers could buy legitimate Kylie Cosmetics products was directly from her website.
"Hey guys, so I've come across this website called kyliecosmeticsoutlet.com. It looks exactly like mine, but it's not," the 19-year-old said in a video posted on Snapchat.
"I want to be really really clear and let you guys know that the only place to get my products is kyliecosmetics.com, and anywhere else is fake."
She added: "Make sure you guys check the URL because these other websites are selling fake product. It might look exactly like mine, but it's not mine."
"The ingredients that they're using are in these fake products also really, really dangerous, which is my biggest concern."
The star then shared the message: "Please don't let these fake sites take advantage of you."
She also retweeted posts from fans who had been injured using the knock-off make up.
One customer named Emma Morgan posted a video of her lips stuck together after using one of the fake lip kits, and wrote: "fake Koko k I got... Literally has glue in it! So gross!! So not cute."
Kylie, who stars in Keeping Up With The Kardashians, responded to the post saying: "Omg I can't even look."
Another Twitter use said she got an infection in her lip, to which Kylie replied: "Wow I'm so sorry" while another said her mother got a lip kit "with gasoline in".