What does catnip do to cats?

Catnip is perennial herb and member of the mint family. Its active ingredient nepetalactone is found mostly in its leaves and stems. Only about 50% of cats respond to catnip, and of those 50% the response is widely variable in behavior. Catnip is not considered harmful and the responses vary from sedation to hyper activity. Most people use it to attract their cat to a scratching post or to increase playtime with toys.

source: https://aspengrovevet.com/