I gave it to one of my cats quite a while ago. I swear it burned his brains out. He got wired the first time then he wouldn't have anything to do with it.

He had a habit of wanting in through the back door and walked right through the kitchen when I was fixing dinner. Inveriable, he would saunter through just when I was taking something from the stove to the sink. He'd walk so slow, he'd get in my way. I would yell "CAT!!!" at him and all that happened was the skin on his back would crawl but he wouldn't move any faster. Before the catnip he'd yowl, jump and becoming a fuzzy blur on his way out to the garage.

I haven't given any of my cats catnip since.