Modifiers matching ligand:

• natural,
• active,
• synthetic,
• physiological,
• hydrophobic,
• exogenous,
• environmental,
• polar,
• endogenous,
• acidic,
• lipophilic,
• atomic,
• uncharged,
• psychoactive,
• hard,
• hydrophilic,
• neutral,
• additional,
• ionic,
• nonsteroidal,
• complex,
• binding,
• cellular,
• common,
• functional,
• ancillary,
• small,
• organic,
• base,
• biological,
• external,
• charged,
• psychedelic,
• inorganic,
• simple,
• metal,
• potent,
• strong,
• physiologic,
• complementary,
• weak,
• relevant,
• axial,
• nonmetal,
• bound,
• important,
• anionic,
• soft,
• extracellular,
• cationic,

Simple categories matching psychoactive:

• chemical,
• drug,
• substance,
• effect,
• pharmaceutical,
• benzodiazepine,
• medication,
• amine,
• intoxicant,
• herb,
• agent,
• medicine,
• plant,
• ligand,
• food,
• compound,
• alkaloid,
• cactus,
• property,
• peptide,
• stimulant,
• constituent,