I started using clarins during my second trimester and I'm currently 32 weeks (7 months almost 8) and so far I have 0 stretch marks on my belly. I did however, develop some stretch marks in my left breast (it's the bigger one). I will say I was way more focused on my belly than I was on my breasts so my belly has received more of this lotion (morning and night) than my breasts (which started off only about 2 times a week) I now bumped it up to night and day as well.