Results are seen at the cosmetic depth of 0.25mm. Cosmetic micro-needling is considered to work only in the granular & mid spinosum layers. Working on a cosmetic depth (0.3mm and below) releases growth factors by stimulating Keratinocyte cells. Clinical studies have shown that regardless of the depth of injury to the skin, new collagen forms no deeper than 0.6mm. Working above 0.5mm is considered a medical treatment. Micro-Needling at  “medical depths” has shown to be dramatically effective for scar removal, cellulite reduction, stretch marks, hyper-pigmentation and reduction of fine lines and wrinkles.