Well, at least since she had a baby. My GF is very skinny, unfortunately when you’re really skinny sometimes you get stretch marks on your belly. She’s been trying to get them to go away her whole life and is very self conscious about them. She has talked to surgeons in the past and even they admitted there is no miracle cure. While this is not an instant cure, I can tell you I’ve seen significant improvement since she bought this. And it’s only been about 3 weeks. On the bottle it says usually improvement not noticed until 8-12 weeks, but she already is very happy with the improvements she’s seen. The stretch marks have faded considerably. I’ll add more information in 8 weeks to tell you our final call for it. But I can tell you, this wrinkle cream does what it claims. Pricey, yes. Worth it? You know it!