I've been doing it for months. There's no side effects, just make sure you clean the roller good after each use to avoid infections. I soaked mine in a cup of rubbing alcohol, washed it off with hot water and then let it air dry.
I thought this needling thing was just a hype in 2013 until page 15 from 2008 came up. Thanks for bumping this. I'll try to dig my head and seed it with snake oils (panax ginseng, eclipta alba, apigenin, oleanolic acid, biotinyl tripeptide, sophora angustifolia, etc.). Let's see whether I'll reach a harvest time or not, but I believe I will.