Nepetalactone

Pharmacology & Research

Nepetalactone is the defining iridoid monoterpene lactone of catnip, making up the great majority of the essential oil. It has one genuinely strong story — insect and tick repellency — and a load-bearing safety fact behind it: nepetalactone activates insect TRPA1 but does not activate human TRPA1 ^{2Reference 2Melo N et al. · 2021The irritant receptor TRPA1 mediates the mosquito repellent effect of catnipView study →}, which is why catnip is a safe, insect-selective repellent. Its other reputations are weaker than the folklore suggests: the famous human “sedative” claim has no clean molecular anchor and belongs to the herb (and to different Nepeta species), not to the isolate ^{8Reference 8Sharma A et al. · 2021The genus Nepeta: traditional uses, phytochemicals and pharmacological propertiesView study →}. All isolate evidence is entomological or whole-oil; there are no human therapeutic trials.

1. Insect / tick repellent

Nepetalactone-rich catnip oil repels mosquitoes, ticks and filth flies; a 6% catnip-oil lotion performed comparably to ~15% DEET by human landing catch in Uganda ^{1Reference 1Batume C et al. · 2026Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern UgandaView study →}, and topical/WHO bioassays confirm mosquito, ixodid-tick and poultry-mite repellency with potency tracking the diastereomer ratio ^{3,4Reference 3Birkett MA et al. · 2011Repellent activity of catmint, Nepeta cataria, and iridoid nepetalactone isomers against Afro-tropical mosquitoes, ixodid ticks and red poultry mitesView study →Reference 4Amiro M et al. · 2026Chemical composition matters: the role of nepetalactone isomers in tick repellencyView study →}. The mechanism is agonism of the insect irritant receptor TRPA1 ^{2Reference 2Melo N et al. · 2021The irritant receptor TRPA1 mediates the mosquito repellent effect of catnipView study →}.

Gap: the human field data are on whole catnip oil, not isolated nepetalactone, so the isolate’s own efficacy and duration in people are inferred; it is a repellent, not an insecticidal kill agent ^{1Reference 1Batume C et al. · 2026Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern UgandaView study →}.

2. Cat attractant response

Nepetalactone is the volatile that triggers the classic sniff–lick–roll euphoria response in domestic cats and some other felids, acting via the olfactory route (nasal detection, not ingestion) in genetically responsive individuals.

Gap: presented here as well-documented natural history rather than trial pharmacology — this pass did not verify a dedicated mechanistic citation for the feline response.

3. Antimicrobial

Nepetalactone-rich catnip essential oil shows in-vitro activity against food-borne ^{6Reference 6Zomorodian K et al. · 2012Chemical composition and antimicrobial activities of essential oils from Nepeta cataria against common causes of food-borne infectionsView study →} and canine skin ^{7Reference 7Borlace GN et al. · 2024Antimicrobial effects of catnip (Nepeta cataria) essential oil against canine skin-infection pathogensView study →} pathogens, with nepetalactone as the principal component.

Gap: preclinical only, attributed to the whole oil, with no isolated-compound MIC hierarchy or in-vivo/clinical follow-through ^{6,7Reference 6Zomorodian K et al. · 2012Chemical composition and antimicrobial activities of essential oils from Nepeta cataria against common causes of food-borne infectionsView study →Reference 7Borlace GN et al. · 2024Antimicrobial effects of catnip (Nepeta cataria) essential oil against canine skin-infection pathogensView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
Insect TRPA1 (irritant receptor)	agonist → aversive avoidance	mosquito, tick, fly repellency
Human TRPA1	no activation	the basis of insect-selective safety in humans
Feline olfactory pathway	volatile detection → stereotyped euphoric behaviour	cat attractant response (descriptive)
Microbial membranes (whole oil)	in-vitro growth inhibition	antimicrobial (preclinical)

Pharmacokinetics

There is no human pharmacokinetic data. Nepetalactone is a small, volatile iridoid lactone that, in its lead uses, acts in the vapour/topical phase at insect chemosensory receptors and (in cats) via olfactory detection — routes where systemic ADME is largely not the operative question. No absorption, distribution, metabolism, half-life or excretion parameters are established for the isolate in humans.

Clinical trials

There are no human trials of isolated nepetalactone. The only human data in the source set are a repellency field study on whole catnip oil ^{1Reference 1Batume C et al. · 2026Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern UgandaView study →} and insomnia/anxiety trials on Nepeta menthoides — a different species — neither of which isolates nepetalactone’s contribution.

Last checked: July 2026.

Toxicity & Safety

Nepetalactone has low apparent toxicity at the exposures studied; catnip oil has been evaluated for safety in repellent research, including acute-toxicity assessment alongside filth-fly bioassays, without a notable hazard flagged for repellent use ^{5Reference 5Zhu JJ et al. · 2009Efficacy and safety of catnip (Nepeta cataria) as a novel filth-fly repellentView study →}. As with most concentrated essential-oil constituents, the neat compound should be treated as a potential skin and mucous-membrane irritant — consistent with its role as an insect TRPA1 irritant-receptor agonist — but it does not activate human TRPA1, which underlies catnip’s benign profile in people ^{2Reference 2Melo N et al. · 2021The irritant receptor TRPA1 mediates the mosquito repellent effect of catnipView study →}. No genotoxicity, carcinogenicity or organ-toxicity signal is established for the isolate. Note that catnip’s folk sedative reputation should not be read onto this molecule: the one positive rodent datapoint is attributed to its co-marker nepetalic acid, and the human sleep/anxiety trials used a different Nepeta species ^{8Reference 8Sharma A et al. · 2021The genus Nepeta: traditional uses, phytochemicals and pharmacological propertiesView study →}.

Pregnancy & lactation

Insufficient data → avoid concentrated/internal use. Catnip the herb is traditionally cautioned as an emmenagogue, but that caution belongs to the plant; for nepetalactone specifically there are no reproductive-safety data, so concentrated or therapeutic/internal use is best avoided in pregnancy and lactation. Incidental exposure from a topical catnip-oil repellent is a separate, lower-concern context but is still un-studied in pregnancy.

Dosage

There is no established human therapeutic dose — nepetalactone is not used as an isolated internal therapeutic. Practical exposure is topical/environmental via catnip essential oil in repellent formulations (e.g. low-single-digit-percent oil lotions performed comparably to ~15% DEET in field testing ^{1Reference 1Batume C et al. · 2026Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern UgandaView study →}); that is an oil-formulation figure, not an isolated-compound dose, and no internal dosing is supported.

References