The death grip of heroin is mostly unrelated to the actual medical properties of heroin (or most opioids). The worst health effects come from the impurities in the substance (Strychnine, a common additive, is generally speaking not a substance beneficial to your health), the conditions under which it's used (shared needles, lack of hygiene) and the treadmill of having to organize funds for the next shot. Medically speaking, heroin is less harmful than alcohol. It's very hard to actually overdose if the purity is constant. It's a preferred drug for pallative care in many countries since it's effective and relatively easy to use (similar tor morphine).
So if you truly care about the health of the afflicted persons, legalization with a strict control is the most effective option that is currently on the table.
Heroin addicts on a constant regime of pure heroin can be well-functioning members of society. See https://en.wikipedia.org/wiki/Heroin-assisted_treatment
So if you truly care about the health of the afflicted persons, legalization with a strict control is the most effective option that is currently on the table.