We use utilized natural North American catnip for GiGwi refillable catnip toys. These toys have a special fastener, so that fresh catnip teabags can be added again and again – to last all your cat's nine lives. Catnip is a natural, non-addicting herb that encourages playful behaviour for about 70percent of cats, which have an inherited gene that compels them to respond to catnip. Included ziplock bags maintain maximum freshness and keep your extra catnip in necessary conditions until needed.