Picking the right Roller All derma rollers aren’t the same. The key difference? The needle length. 0.25 mm: Great if you’re just trying to get your scalp to absorb serums better. 0.5 mm ...

Generally, a needle length of 0.25 millimeters (mm ... Clean your dermaroller with unscented detergent. Create a soapy water mix in a plastic container, then swish around the roller vigorously ...