I used cocoa butter my whole pregnancy (currently 36 week) but still got stretch marks in the third trimester. It did prevent me from getting any.on my boobs! I've heard Merderma works for stretch marks or scars will help clear them away or Bio oil.
Nothing can take your stretch marks away once you already have them but it's supposed to help lighten them so they blend in better with the rest of your skin.
I started putting it on before i got strech marks and i didint get any