Yes, but I think heroin, and other drugs of that caliber, should always be illegal. That it is such a persecuted substance must keep people from trying it, even if it also causes a lot of crime. In the end, I feel that when something is that destructive and poisonous, mere possession of it should be a big deal for the deterrant effect.
Adults should have the legal right to poison themselves. They should not have the legal authority to stop other adults from self poisoning.