The Kardashian sisters have gone through major transformations through the years, but Khloe Kardashian's recent changes are drawing major attention.

According to Radar Online, the reality star's lips have gone through the most drastic change, as some doctors caution about possible side effects. "There is no doubt that Kardashians love their lip filler," Dr. Sheila Nazarian—who has not treated the star—tells Radar Online. "But Khloe has probably had a full syringe added."

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khloe kardashian lips

The extreme enhancements have changed Kardashian's face from when we first met her, and experts warn that too much lip filler can cause damage to the mouth and result in "duck lips."

Take a look at the gallery below to see Khloe Kardashian's transformation through the years: