You're all preaching to the choir. He probably knows all that stuff by heart.
All drugs are deep down a form of escapism, like literature and TV and sport.
As much as we rationalize its use or derive long term benefits off them, they are still a form of escapism.
It all comes down to choice, information and responsibility. If he knows the risks of partaking in that particular drug (which he prolly does) than it's his own choice and we shouldn't judge it.
I don't know one single person that doesn't use escapism in one way or another. The question is how safe is that particular form of escapism. Heroine is not a safe one in terms of addiction but we cannot make the choice for him. We can preach all that we want but if in his mind he is going to do H, he's going to do H regardless.
Especially if we approach it with the 'my drug is better than yours' attitude.
Cut the pharma-moralist crap, we've all had enough of that from our governments. If you have pertinent info or advise to give, by all means do so. But posting to say "heroin's bad, mmmkay?" is useless.
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As for the original question:
There should be no synergy, potentiation or harmful interaction between heroin and psilocybin.
Tryptamines + opiates in not an unsafe combo.
But personally i don't understand why would someone want to mix both. They have opposite effects, the heroin will dull the mushroom trip and the shrooms will take away the blissful worry-less opiate state.
One is a mind manifesting drug, the other is a mind numbing euphoriant. They will cancel each other.
If you have to do the heroin wait for the day after the trip or at least till you're coming down.
And please be careful and extremely moderate with that stuff. Opiate addiction will creep up on you without you never knowing. Than when you notice it, you'll have a huge thirsty violent gorilla behind your back that'll keep demanding his fix over and over again.
