With microneedling, the needle size is not what varies during a procedure, but rather needle depth. Dermarollers on the market can only go to 1.5mm depth, while microneedling devices handled by experts can penetrate up to 3.0mm depths. Additionally, stretch marks are difficult to treat, so while microneedling can help diminish their appearance, this may take multiple rounds of treatment. Going forward, I would recommend you to complete multiple consultations with board certified experts. This way, they can assess if microneedling is the ideal treatment for you and then craft a treatment plan to target your concerns. Best of luck! Kian Karimi MD, FACS