The 0.5mm microneedleis best for reducing or removing scars, wrinkles, hyperpigmentation, and UV damage. It also has more added benefit for skin care absorption than 0.25mm needle size. If you want to have a monthly dermaroller treatment, this is the ideal needle size to choose. This needle size is also less painful compared with the longer microneedles. You may not even use need a numbing cream to ease the pain but you may have longer recovery time which usually takes a few days. Other common side effects are dryness, redness and peeling.