Well if you have never ran dhb I would first buy a single.vial from a source and see how you do with pip, cuz some people can't take dhb bcuz of pip issues, but I will say qsc dhb is pretty smooth vs other brands of dhb and it doesn't have any super solvents which is a plus. And dhb is not liver toxic like that other dude was saying "risk on liver", so don't worry about that. Personally I got way better results with dhb than npp or deca. It does take a little bit longer for dhb to really kick in and show it's results and a lot of people have to cut their dhb cycles short because of pip issues so they don't see the full results. If you choose dhb, I would try to keep injections with only 1ml of dhb per shot mixed with test to help smooth it out. And 400-600 dhb is perfect. I ran it at 400 with around 400 test c.