Human PET occupancy: the share of a receptor or transporter a drug occupies at clinical doses — and the effect that appears at each level.
One row per target. Each box is an occupancy band tied to an effect; dashed boxes are low-occupancy or add-on (synergy) ranges, the right-hand boxes are toxicity.
Drag the vertical line to any occupancy; the bands it crosses light up with their effects.
The pattern: antagonists work at roughly 65–80% (D2 65–78%, SERT 75–90%) and misbehave above it (EPS >78%, heavy H1 sedation >50%); partial agonists need more (D2 80–95%) because they also stimulate.
Population averages from PET studies; individual drugs and doses vary.