The 18-year-old has admitted to having temporary lip fillers but, in a new essay on her official website, she tells fans that speculation she's had some help in the bust department is totally false.
Kylie instead put her fuller bust down to weight gain.
Kylie wrote: "No, people – I haven't gotten breast implants! Everyone is obsessed with that. Truth is, as I've gotten older, I've gained 15 pounds and my body has changed. I've definitely filled out."
The Keeping Up With The Kardashians star added that she's also embraced non-surgical ways of enhancing her look, including the Kardashian favourite trick of contouring.
"Working with some of the best makeup artists has taught me a lot of amazing tricks to making me feel more confident and I can't wait to share them with you guys," she said."I swear there are things you can do to work on problem areas without having to think about plastic surgery."
But as for the future, the star said she wouldn't rule out surgery: "Never say never."
Kylie launched her official website and app in New York last week, and already it's been a huge success. It's reported to have pulled in more subscribers than the websites and apps belonging to sisters Kim, Khloe and Kendall combined.
All you need to know about Kylie Jenner: