Do you remember when that one company decided to come out with a product that was both a shampoo and a conditioner in one bottle? Ever since then people have been trying to make their products available for more than one purpose. A quality stretch marks oil will be able to prevent and reduce marks. It can help prevent lines from appearing when used during something like a pregnancy and it can reduce marks that have already appeared. There should be no reason that you have to buy a product for both circumstances. This is a waste of your money to buy both.