depends on what your brewing, if your brewing syno or fina ***************, and you do it right, then you have a for sure mg/ml and a for sure sterility, so imo homebrew is the safest thing you can do, you know what it is cause you made it and you know what it's dosed at provided you know what the fuck your doing.
homebrewing powder is different, you don't know what is in the powder however you can assure sterility but not what your injecting. same as using ug pretty much except guarenteed sterility.