It's safer with multiple filterations through cotton. It's safe with a micron filter. All my veins are okay right now, I usually just filter once cuz I'm a dumbass, I would get will-filters but, I would have to get them deleivered to my house with my parents,sigh. But, really, filter those bitches once atleast(mine come back clear as water and I use 1mg) Please don't say you've been doing 4mg with no filter. I'm thinking of Switching to methadone cuz of this though I don't wanna shoot my whole life, subs of all things, and go on vacations...but I'm so excited about this next vaycay, gimmie some rushes!