Does 0.5mm derma rolling on scalp affects hair follicles?

I cannot provide a formal assessment without seeing you in my clinic. Using a dermal roller will help stimulate a response on the scalp, but there are better treatment options. In my practice I recommend the use of microneedling with PRP, sometimes in combination with minoxidil and finasteride to customize hair regrowth treatments for the unique needs of each of my patients. We have successfully treated many cases like this, without the use of a dermal roller. I recommend scheduling a consultation with a board-certified cosmetic dermatologist who is an expert in hair restoration for a formal assessment.

Studies  have shown that dermarolling alone is an effective treatment for hair restoration. In my opinion, a roller should not have pins longer than .5 mm. The purpose is to stimulate growth factors without inflammation or bleeding.Jeff Rapaport MD FAADRealself All-star

I would say that the depth is generally not enough to see great results but you can try to use it for a few weeks then if you’re not seeing ANY improvement switch to a longer roller. The science shows that it works!