Review (1/5): Stop using derma rollers on your hair - your going to thin out your hair
Derma rollers tend to break the strands of hairs so it can kinda cut the hairs. It will grow back but if your not looking for a hair cut this could be a problem. You can easily thin out your hair with any derma roller. If you want my suggestion please use a nano microneedle or stamp (going vertical). With the nano needle you can easily infuse serums. Castro oil is good and any other healthy hair serums.