In fact, when cats smell catnip it releases a lot of endorphins – it’s quite similar to the ‘natural high’ humans get from exercise.

Why do we think it's OK to give concentrated catnip to intoxicate a pet, and then be amused by the 'intoxicated' behavior?

Silver vine sticks are less likely to cause the ‘catnip effect’, causing only one in five to respond in the study, likely because they have lower amounts of the necessary chemicals.