I derma roll and tout it but I don't think that it grows hair so much as it is healing to the skin, which might somehow cause significant amounts of hair to sprout. It's great for healing scars after transplants and helping them to sit properly. But there's something about the hair growth and the pictures that I have seen that indicate that this isn't a viable option for anyone long-term. I have a feeling that it might work at first but then it fades gradually. I haven't looked at pics in a long time. Some of them are impressive without really being cosmetically significant for he really bald ones. Derma-rolling and micro needling are no fun to me at all so it's hard to stay on a program which I mostly have for several years but currently I am derma rolling with almost 0mm it appears that I got from Amazon. I micro needle but I only use the lowest setting and least painful height. I do both on my face and neck and arms as well followed by Estrogel, Retin-A and liquid minoxidil once every week or two. It's a bit of an ordeal but if I were to create my own hair formula those three things would be in it.