I just wanted to say you really shouldn't be using a Derma Roller 5 times a week. The only kinds of rollers you can use 3 - 5 times a week are the ones with needle size 0.25mm or less. If you are using a 0.5,1.0 or 1.5mm (or even more) roller then you could cause some serious damage rolling daily. You are meant to roll once every 4 - 6 weeks! You may see 'results' but they will only be temporary, and you could infact end up damaging you skin and making the stretch marks look worse than when you started. You can find more info here: (it's a thread dedicated to using a derma roller to treat stretch marks) http://www.essentialdayspa.com/forum/viewthread.php?tid=33739
Take no notice of the instructions the sellers give you. They are purely a business, not a doctor etc. They are there purely to sell a product and make profit. Think about it, the more you user your roller, the more often you will need to replace it... see what I am getting at?