In the medical world, this is typically quantified by the Therapeutic Index[1], which is basically how much margin there is between an effective (therapeutic) d

In the medical world, this is typically quantified by the Therapeutic Index[1], which is basically how much margin there is between an effective (therapeutic) dose and a lethal dose. (Fentanyl and heroin have notoriously thin margins, while cannabis is famously wide.) It's a big consideration in what's OTC vs Rx, and what guardrails (inpatient only, regular blood draws, etc) are needed. There was a good "magic quadrant"-style plot of this against addictive potential, but I can't seem to find it just yet. (This [2] is close.) It doesn't consider externalities, so it's not great for the "do drugs and you'll end up unemployed, and if you're unemployed you'll end up homeless, and homeless people are a cost on the community" class of arguments. [1] https://en.wikipedia.org/wiki/Therapeutic_index [2] https://en.m.wikipedia.org/wiki/File:Rational_scale_to_assess_the_harm_of_drugs_%28mean_physical_harm_and_mean_dependence%29.svg