Catnip makes cats “crazy” mainly because of a chemical in the plant called nepetalactone , which interacts with receptors in a cat’s nose and triggers brain pathways related to pleasure, excitement, and mood.

What’s in catnip?

  • Catnip is a herb (Nepeta cataria) from the mint family.
  • Its key active compounds are iridoids, especially nepetalactone (in catnip) and a closely related chemical called nepetalactol in similar plants like silver vine.
  • These molecules are volatile oils that evaporate into the air and are picked up by the cat’s olfactory system when sniffed.

How it makes cats act wild

  • When a cat smells nepetalactone, it binds to receptors in the nose that send signals to brain regions involved in emotion and reward, producing a state often compared to euphoria.
  • Research suggests these plant chemicals can activate the cat’s opioid system in a way loosely analogous to how certain drugs affect humans, which helps explain the rolling, rubbing, and excited behavior.
  • The “crazy” phase usually lasts around 10–15 minutes, after which the cat becomes temporarily unresponsive to more catnip until the receptors reset.

Why not all cats react

  • Sensitivity to nepetalactone is genetic: only an estimated majority (often cited around 60–80%) of cats respond strongly, while others show little or no reaction.
  • Both domestic and wild cats can be sensitive, but kittens often do not react until they are a few months old.

Extra fun fact

  • The nepetalactone/nepetalactol compounds do more than entertain cats: they also help repel mosquitoes and other insects, which may be part of why the plant evolved them in the first place.

TL;DR: The thing in catnip that makes cats act “crazy” is the plant oil nepetalactone, which, when sniffed, stimulates smell receptors and brain reward pathways to create a short-lived, euphoric buzz in cats.

Information gathered from public forums or data available on the internet and portrayed here.