As you may have noticed, above you will find words for "The ability of certain endogenous chemicals (notably cholecystokinin and neuropeptide Y) to counter the effects of exogenous analgesics (such as morphine) or endogenous pain-inhibiting neurotransmitters and modulators.". Hover the mouse over the word you'd like to know more about to view its definition. Click to find a better fitting word. Finally, thanks to ChatGPT, the overall results have been greatly improved.