Microdosing involves taking a small, sub-perceptual dose of a psychedelic substance. In contrast, a full psychedelic experience involves taking a larger quantity that produces more hallucinogenic effects, such as altered perceptions, emotions, and insights.
The main difference is the intensity and duration of the effects, with microdosing producing subtle effects and minimal interference with day-to-day activities and a full psychedelic experience requiring more time and potentially having different effects with more profound transformative mood effects.