This 0.25 mm derma roller is marketed for general micro needling, but within The Beauty Doctrine framework, it is best reserved for scalp use only. The roller format uses needles arranged on a cylinder, which means the needles enter and exit the skin at an angle, increasing the risk of micro tears when used on delicate facial tissue. This can lead to uneven collagen induction, long-term texture irregularities, and sensitivity.

On the scalp, however, the skin is thicker and more forgiving, and a shallow 0.25 mm depth is appropriate for supporting microcirculation and improving absorption of growth supportive topicals. This makes the device a practical and low cost tool for early hair thinning without the injury risk associated with deeper at home micro needling.
For face focused micro needling, straight needle pens deliver vertical penetration and are safer in controlled, professional settings not at home. Thus, the TBD recommendation is clear, this tool is not for facial use but is a helpful addition to scalp care protocols.