Part of the problem of prohibition is that it drives up the potency of drugs which leads to the situation where you get fentanyl instead of heroin. This effect

Part of the problem of prohibition is that it drives up the potency of drugs which leads to the situation where you get fentanyl instead of heroin. This effect was coined the "iron law of prohibition" by economist Richard Cowan. More powerful drugs lead to stronger addictions and more accidental over doses. Reference: https://en.m.wikipedia.org/wiki/Iron_law_of_prohibition https://en.m.wikipedia.org/wiki/Iron_law_of_prohibition