this is in a bottle right? read the label and find out what's in it, if it's an oral preparation there might (i don't know really) be some shit you don't want to get into your veins. there's a whole lot of information around here about proper IV techniques, you just need to search a bit. 10mg IV morphine is enough without tolerance. hell, even 5mg will provide a rush if you push the plunger quick enough ime
also, for the sake of harm reduction, if you have never done the needle before, you don't want to get into all that shit man, seriously... just drink that shit man, anywhere from 30-50mg should give you a very nice relaxing buzz. i personally like morphine, find it very sedating.
and just out of curiosity? is this an oral morphine preparation or is it opium tincture? because these do taste very bitter
EDIT: nevermind, this shit is blue? wtf there probably is colourant/dye in this shit that probably wouldn't be a good idea to be in your veins, and nvm the opium tincure question, if it's blue it's not it