I understand what you are saying. I agree that heroin by itself is not very harmful to the body relative to some other drugs.

But let me be more clear about what I mean by "death grip".

When someone cares so much about a drug that it becomes the focal point of their lives, where they become so utterly ruled by the object of their addiction that friends and family and all else not the drug become secondary fixtures in their lives, then they have become the walking dead and are very much in the death grip.

I have seen it with friends. Some are still breathing, some are not.

Sure people on medical grade heroin regimens can continue to exist, but the drug will kill them inside nonetheless.

Revitalization is possible of course, but it is exceedingly difficult.