Microdosing is a technique for studying the behavior of drugs in humans through the administration of doses so low (‘sub-therapeutic’) they are unlikely to produce whole-body effects, but high enough to allow the cellular response to be studied. This allows the observation of a drug’s pharmacokinetics with a low risk of side effects. This is called a ‘Phase 0 study’ and is usually conducted before clinical Phase I to predict whether a drug is viable for the next phase of testing. Human microdosing aims to reduce the resources spent on non-viable drugs and the amount of testing done on animals.
Psychedelic drugs are also sometimes used at sub-therapeutic doses for non-hallucinogenic effects. For example, LSD at one tenth the normal dose has been reported to have antidepressant properties and is said to aid in problem solving.
The Daily Omnivore 