HappyNip™ Catnip Blend Loose Catnip is an exciting blend of silvervine and catnip. Silvervine, a wild-growing herb foraged in the mountains of Japan and China, has a strong natural effect on cats, even some that don’t respond to catnip. After extensive testing to find the perfect blend, HappyNip™ was created as an ideal alternative for finicky felines who need a little extra excitement! HappyNip is more potent than catnip and as pure as can be! Most cats respond to catnip with a burst of energetic activity followed by a purrfectly calm mellow period.