Not closely, anyway. Cannabis comes from the Cannabaceae family (which includes hemp, hops, nettle trees, and hackberry, to name a few). Catnip, more formally Nepeta cataria, is a member of the mint family (or Lamiaceae) along with many popular herbs like basil, rosemary, oregano, sage, thyme, and lavender.
This similarity can almost be boiled down to “both cannabis and catnip are plants” because all plants use chemical constituents – both psychoactive or non-intoxicating – to protect themselves. Plants don’t have immune systems, legs, or teeth/claws (except maybe the Venus fly trap) like animals do, so they use a cocktail of natural compounds to deter predators and pests, attract pollinators, and resist pathogens.
Cannabis produces THC and other cannabinoids for a variety of protective purposes. Catnip produces the pheromone-like terpenoid nepetalactone, which is known to repel cockroaches and mosquitoes, but why would it attract cats?
Author Michael Pollan in The Pot Book shares the story of a cat who would constantly forget where to find the catnip bush in his garden. “It occurred to me that this might be a kind of evolutionary strategy on the part of the plant: instead of killing the pest, it would just really confuse it,” he speculates. “Killing pests can be counterproductive, because they breed or select for resistance very quickly…If the plant merely confuses the pests or disables their memory, it can defend itself against them overindulging.”
THC gets us high by activating receptors in the brain, binding to what’s called the endocannabinoid system. Cats also have an endocannabinoid system, so they too can feel the psychoactive effects of cannabis – but contrary to human experience, cannabis is not pleasurable to cats, so let them stick to the ‘nip and do not feed them cannabis.
Catnip’s nepetalactone is absorbed through tissues in the cat’s nasal cavity and creates a domino effect in the brain, affecting areas from the amygdala to the hypothalamus to the pituitary gland. It can make cats feel aggressive, playful, lethargic, or sexually aroused (sorry if catnip is weird now). Vaporizing or brewing catnip into tea is said to have subtly relaxing effects for humans, but the reason catnip intoxicates cats uniquely is because it mimics a pheromone cats are keen to pick up. Hence some of the awkward aforementioned side effects.
As I try to write this, my two cats are having polar opposite reactions to catnip. The overweight Siamese male is shoveling catnip into his nostrils with his tongue, rolling in it until every inch of his loaf-like body is covered in dried leaves. The house’s alpha-female, a tiny 9-pound Persian, takes a few sniffs, watches the boy with plotting eyes, and then tackles him, biting the back of his neck in a show of unchallenged dominance.
Just as cats respond differently to catnip (in fact, up to one-third don’t respond to catnip at all due to genetics), humans respond differently to cannabis. A strain that makes one person feel relaxed and anxiety-free can make another feel restless, on-edge, and paranoid. It all comes down to a variety of biological factors unique to each individual.
These are just some fundamental similarities and differences you’ll find between man’s and cat’s favorite herbs. The plant kingdom is full of other fascinating examples, but catnip is arguably the most entertaining as it reduces the most dignified and serious creature to a ridiculous floor-bent state that many of us can relate to after a good-sized dab or an overweight blunt.