What if I use a microneedle with a 0.5mm depth?

The avascular part of the scalp averages 0.5mm thick, and below the epidermis of the scalp lies the upper reticular dermis. The hair follicles in the upper reticular dermis have stem cells nearby, usually above the sebaceous gland. Wounding this area is critical to getting a response to the healing cascade with microneedling that stimulates these stem cells. If you go down 0.5mm, you will not reach this area, and if you go down to 0.075, it will not induce the best result of the microneedling healing cascade.