Catnip is considered toxic to pets, because it causes a change in the Central Nervous system. My suggestion would be to give it to your cat, but in VERY small amounts, or even put it in a cat toy. I would only give it to your cat every now and then.
This is coming from someone whose cat ate over a pound and a half of cat nip in one sitting and ended up in the critical care unit for a week at the hospital. Thanks. Like I said, in moderation is okay. Cats can actually OVERDOSE on it which leads to an impaired neurological state.