I'm of two minds about that. While I agree that I ought to have full autonomy over my own body, at the same time the state has a vested interest in not allowing its population to fall victim to life-destroying drugs, especially when those drugs target the most vulnerable members.
Russia's heroin problem has been rising and rising -- apparently 2% of the population are addicted, and much higher rates for certain segments [1] -- and people talk of a "lost" generation. And it may get even worse.
I think our social contract with the state involves not allowing that to happen to its population.
[1] https://www.npr.org/templates/story/story.php?storyId=120792...