derma roller - aka micro needling

So last month my sis in AZ tells me her derm told her to use a derma roller .5 for her face scar and a 1.0 for her belly stretch marks - told her to use hyaluronic acid after tx and to do weekly. - she tells me it works better than any peel or professional procedure she has ever tried. - Im paying 1k for each gentleYAG lazer I have done so I order the derma roller (30$) and H. Acid (17$) from Amazon. Ive used it twice now and it really does seem to work. My sis was pretty excited about it which is why I tried it. It hurts pretty bad but my brachioplasty scars (2 years old) really reduced in size and color. 10 year old tummy stretch marks also are much improved. I cant wait to see if it continues to improve. I just did it on my face and the backs of my hands.
Has anyone else used this? How did it work for you?

never heard of this. i am going to look it up. thank you. also, if they have it on amazon, there should be lots of reviews-?