'kidney-protective' originates from Modern English, specifically the compound of the noun 'kidney' and the adjective 'protective'.

'protective' comes from Latin 'protegere' (where 'pro-' meant 'before' or 'in front of' and 'tegere' meant 'to cover'), passing into Old French and Middle English as forms meaning 'to guard or shield'; 'kidney' is an Old English word for the organ that continued into Middle and Modern English. The compound 'kidney-protective' is a modern coinage formed in scientific and medical usage.

Initially a straightforward compound denoting something that protects the kidney (literal combination of 'kidney' + 'protective'); over time it has been specialized in clinical and pharmacological contexts to mean 'having renoprotective properties.'