A really vicious heroin substitute is now circulating. The drug is made from codeine-so expect it to show up where codeine is readily available over-the-counter (Canada, Mexico, etc.). The drug is about 4x more addictive than Heroin and virtually impossible to stop using once addicted. Life expectancy for an addict is about 1 year.
A short introduction to a cheap powerful Heroin replacement drug is attached Here
A graphic YouTube video of its physical effects is attached here.