The Celebrity Big Brother star, 19, posted a picture of her newly-plumped lips - with lashings of red lipstick - on the social networking website.
Alongside the selfie, she wrote the message: "@DrPaulNassif new pout looks so lovely. Thank you, Doc ;) x."
Dr. Paul Nassif was famously married to Real Housewives Of Beverly Hills star Adrienne Maloof, but the pair divorced last year. He also appeared on the TV show Dr. 90210.
Courtney has never been shy about her cosmetic procedures, and is open about the DD breast implants she got earlier this year.
The peroxide blonde American became famous when she married 51-year-old actor Doug Hutchison at just 16.
She was the sixth housemate to be evicted from the Celebrity Big Brother house in September.
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