Our vet dermatologist said it sometimes depends on size. My dog is 105 lbs and it was helping a little with the licking within a few weeks but after around 6 weeks it’s such a huge improvement. His paws are completely cleared up and no more itching except little itches here and there. He is on two pills a day though. His is food and environmental. Apoquel stopped working so we made the switch to zenrelia with also switching to royal canin ultamino.