Catnip repels mosquitoes on you. Your cat already knew.

What catnip actually does to your cat

Short answer: Catnip (Nepeta cataria) contains nepetalactone, which binds to a cat's olfactory receptors and triggers a brief, harmless response in about half of cats. It's hereditary, not addictive, and safe as enrichment in its plant or dried form.

When a responsive cat meets catnip, the reaction is unmistakable: rolling, rubbing, drooling, vocalising, and a burst of activity that lasts roughly 10 minutes before fading. About half of cats respond — the Merck Veterinary Manual places it around 50–60% — and the trait is inherited, so a non-responder kitten will be a non-responder adult. Kittens under a few months old and older cats often don't react at all.

In its plant and dried form, catnip is widely used as enrichment and is well tolerated. It is not addictive, and serious harm from the herb itself is rare — eating too much dried catnip can cause mild vomiting or diarrhoea, which resolves on its own. This is the form to give your cat.

The repellent your cat can't use

Short answer: The same nepetalactone that enchants cats repels mosquitoes — a 6% catnip oil lotion matched 15% DEET in a 2026 field trial. But concentrated essential oil is a human-use product. Cats process essential oils poorly, so the repellent stays off your cat.

In March 2026, a peer-reviewed study in Scientific Reports (Nature Portfolio) found that a lotion containing 6% catnip essential oil performed as well as 15% DEET over a four-hour evening field test in Eastern Uganda, using the Human Landing Catch method against real mosquito populations including Anopheles gambiae, a malaria vector. Nepetalactone repels insects by activating the TRPA1 irritant channel — the same compound your cat rolls in.

Here is the catch. Cats are deficient in glucuronyl transferase, a liver enzyme that helps clear many essential-oil compounds, which makes them unusually sensitive to concentrated oils. Veterinary guidance is explicit: do not apply concentrated essential oils directly to cats, and prevent ingestion. Catnip essential oil is no exception. The repellent is for your skin, not your cat's.

Living with catnip and a cat

Short answer: Keep the concentrated oil for you, give the dried herb to the cat, and store the repellent where a catnip-obsessed cat can't reach it. The two forms don't mix.

• Store oil closed and high. Catnip essential oil and any mixed repellent go in a closed bottle, out of reach. A cat that responds to catnip will find an open bottle interesting — that's the exposure you're avoiding.
• Let applied repellent dry. After applying catnip repellent to your skin, do not let cats lick treated skin; let it absorb and dry, wash it off before close contact if your cat is attracted to the scent, and wipe away any excess.
• Give the cat the safe form. Dried catnip, catnip toys, or a potted catnip plant are the enriching, cat-appropriate versions. This is how your cat enjoys the plant.
• Never apply oil to a cat. Concentrated essential oils stay off cats entirely — catnip oil included. If you suspect ingestion or a reaction, call your vet or the ASPCA Animal Poison Control Center (888-426-4435).