'ptyalogogic' originates from Greek (via New/Modern Latin), specifically the Greek word 'πτυάλον' ('ptyalon') meaning 'saliva' and 'ἀγωγός' ('agōgos') meaning 'leading' (combined in the Latinized form '-agogic').

'ptyalogogic' changed from the New/Modern Latin formation 'ptyalogogicus' (formed by the combining form 'ptyalo-' + '-agogic') and was adopted into English as a technical/medical adjective meaning related to salivation.

Initially it literally meant 'leading or bringing forth saliva', and over time it evolved into the specialized medical sense 'causing or promoting salivation'.