Mouth adapter (1) for oral administration of a fluid mixture, comprising a generally elongate body (10) having a proximally disposed handle end (12) and a distally disposed outlet end (11); a lumen (15) provided in said body (10) adapted for receiving a syringe (2), said syringe (2) comprising a tip (24) extending from a distal end wall (23); and an outlet (16) in communication with said lumen (15) provided in said outlet end (11), wherein said outlet end (11) has a rounded, smooth and substantially rigid outer surface (50), the mouth adapter (1) being provided with stop means (40, 41, 42, 43) for preventing said tip (24) from extending from the exterior surface of the outlet end (11).