Yeah if your in North America and you got powder, your only real options are to sniff or inject. DEF sniff it. (No point to using IV yet and its something u should not do unless utterly unavoidable)
There's no "interaction" btwn Heroin and Oxy. It carries the same dangers as taking oxy and then taking some more oxy. In other words, its just an opiate + an opiate. The only concern is since u don't know the potency and how to guage ur dose with heroin, that dose of heroin u take with the oxy in ur system could be like taking 200mg of oxy (a fat line of heroin) instead of ur usual 40mgs if u follow.
But, taking heroin and oxy the same day Is not like a Benzo + Alcohol combo or a Benzo + Opiate combo---in those 2 situations, the effects of combining are more dangerous than the effects of each one individually. Kinda like oxy + heroin would be equal to 1 + 1 = 2 in math, whereas Benzo + Alcohol would be like 1 + 1 = 200 b/c of the synergy with the 2 drugs
So taking the H is just like redosing with more oxy, but since u can't really gauge how much heroin would be equal to a comfortable dose of oxy, play it safe and take small doses working ur way up. Doing too much H would be like taking too much oxy, not good..
The high is def worth it just sniffed...I used 1 gram+ / day of oxy (12-15 80mg oxy's per day) and snorted heroin gave me a more than sufficient high. The ONLY reason to shoot up as far as I'm concerned, is when you can no longer afford to sustain ur habit by snorting and so you have to shoot up to use more efficiently, but at that point u should revaluate.
Once u shoot up, nothing will ever feel as good, so why jump up ur tolerance b4 u have to? Its kinda like, if u could nod off of 20mg of oxy, would u do something that made it so u needed to take 80mgs to feel the same way? Hell no! So snort for as long as ur still enjoying it, and only when that's not working for u anymore then move on if u must.
Oh and smoke weed, I always appreciated H more after I smoked in the begining, its not as speedy as oxy is, so the weed helped me to appreciate the sedation of H when I started