About the Dermaroller
The main concern lies in creating a safe, sterile environment at home as you risk introducing harmful bacteria into the micro-channels created in the skin which could lead to infection if the device is not properly cleaned. Some at-home devices might have needle lengths that do not classify as medical devices, but then they are not getting into the layer of the skin that would be the most beneficial.
Additionally, a trained practitioner will adjust the needle depth to accommodate the depth of the skin in order to be the most effective for the desired outcome and the dermaroller is a static, shallow depth of less than 0.3 millimeters. With regular and long-term use of a dermaroller, users could see an improvement in skin tone and texture and mild scarring, but it does not result in the same benefits microneedling offers.