> Edit: I would also add that medical trials also have well established methods of determining effective and dangerous exposure levels, and these are used in al

> Edit: I would also add that medical trials also have well established methods of determining effective and dangerous exposure levels, and these are used in almost every Phase 1 trail. Yeah, so the scientist I heard this from didn't say it would be impossible to find the right dose, just that we didn't know the dose yet and we'd have to find it before running a challenge trial. He thought this erased the time savings of a challenge trial versus the normal process.