Timing and route of exposure affects crystal formation in melamine and cyanuric exposed male and female rats: Gavage vs. feeding

► The timing and mode of administration of melamine and cyanuric acid exposure are related to toxicity. ► Renal effects occurred rapidly with staggered exposure to melamine and cyanuric acid but not with consecutive exposure. ► Gavage exposure induced rapid melamine cyanurate crystal formation while feed exposure did not.