Some drugs are developed with a particular mechanism in mind: a known protein target, a known binding site, and a molecule designed to match. For these, scienti

Some drugs are developed with a particular mechanism in mind: a known protein target, a known binding site, and a molecule designed to match. For these, scientists have a good shot at knowing what's going on. Even then, a doctor might not know - they don't need to. Other drugs are developed by a more random method - for example, take every druglike chemical you have on the shelf and put it in a vial with COVID-19. In that case, scientists will try to find the mechanism afterwards, but they might never know for sure.