Compound Monograph
Nepetalactone
Nepetalactone is the defining iridoid monoterpene lactone of catnip — the volatile behind the cat response and a strong insect and tick repellent that acts on insect (not human) TRPA1. Its evidence is entirely preclinical or whole-oil; the human sedative reputation belongs to the herb, not the isolate.
Sources · 1
Where Does It Come From?
Nepetalactone is a naturally occurring iridoid monoterpene lactone, found in Catnip and Catmint. It is well tolerated orally (low toxicity).
Concentration
Content by Source
Concentrations not reported. No percent-dry-weight or mg/g figures have been published for this compound in its source plants.
Nepetalactone at a Glance
Nepetalactone is the iridoid monoterpene lactone that defines catnip — the volatile responsible for the cat response.
It is also a strong insect and tick repellent, and the mechanism is unusually clean: it acts on insect TRPA1, not the human version, which is why it repels insects without irritating people. Comparative work has found it competitive with DEET.
Its evidence is entirely preclinical or entomological.
What It's Used For
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 2The 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 8The genus Nepeta: traditional uses, phytochemicals and pharmacological propertiesView study →.
All isolate evidence is entomological or whole-oil; there are no human therapeutic trials.
Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. Preclinical/whole-oil evidence, so scores stay low by design.
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 1Evaluating 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,
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 1Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern UgandaView study →.
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.
Nepetalactone-rich catnip essential oil shows in-vitro activity against food-borne 6Reference 6Chemical composition and antimicrobial activities of essential oils from Nepeta cataria against common causes of food-borne infectionsView study → and canine skin 7Reference 7Antimicrobial 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,
Mechanisms
| Target / pathway | Effect | Relevant to |
|---|---|---|
| Insect TRPA1 (irritant receptor) | agonist → aversive avoidance | mosquitotickfly repellency |
| Human TRPA1 | no activation | the basis of insect-selective safety in humans |
| Feline olfactory pathway | volatile detection → stereotyped euphoric behavior | 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 vapor/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 1Evaluating 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.
| Completed | Planned | Terminated | Preclinical |
|---|---|---|---|
| —(none, isolate) | — | — | Repellency-led |
Last checked: July 2026.
Toxicity & Safety
The fact that makes nepetalactone a usable repellent is also its main safety fact — it agonizes insect TRPA1 but does not activate the human receptor, which is why it irritates mosquitoes and not you.
- Insect-selective. It activates insect TRPA1 but not human TRPA1, which underlies catnip’s benign profile in people.
- No hazard flagged for repellent use. Catnip oil has been through acute-toxicity assessment in repellent research.
- Avoid concentrated or internal use in pregnancy and lactation. No reproductive-safety data.
- Treat the neat compound as an irritant. Concentrated essential-oil constituents can irritate skin and mucous membranes.
- Don’t read catnip’s sedative folklore onto the molecule. The one positive rodent datapoint belongs to a co-marker, and the human sleep trials used a different Nepeta species.
Full Safety & Interactions Detail
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 5Efficacy 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 2The 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 8The genus Nepeta: traditional uses, phytochemicals and pharmacological propertiesView study →.
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 1Evaluating 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
- Batume C, et al. (2026). Evaluating repellence properties of a catnip essential-oil-based mosquito repellent using the human landing-catch method in Eastern Uganda. Scientific Reports. https://pubmed.ncbi.nlm.nih.gov/41832282/
- Melo N, et al. (2021). The irritant receptor TRPA1 mediates the mosquito repellent effect of catnip. Current Biology. https://pubmed.ncbi.nlm.nih.gov/33667373/
- Birkett MA, et al. (2011). Repellent activity of catmint, Nepeta cataria, and iridoid nepetalactone isomers against Afro-tropical mosquitoes, ixodid ticks and red poultry mites. Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/21056438/
- Amiro M, et al. (2026). Chemical composition matters: the role of nepetalactone isomers in tick repellency. Journal of Chemical Ecology. https://pubmed.ncbi.nlm.nih.gov/41528609/
- Zhu JJ, et al. (2009). Efficacy and safety of catnip (Nepeta cataria) as a novel filth-fly repellent. Medical and Veterinary Entomology. https://pubmed.ncbi.nlm.nih.gov/19712151/
- Zomorodian K, et al. (2012). Chemical composition and antimicrobial activities of essential oils from Nepeta cataria against common causes of food-borne infections. ISRN Pharmaceutics. https://pubmed.ncbi.nlm.nih.gov/22779012/
- Borlace GN, et al. (2024). Antimicrobial effects of catnip (Nepeta cataria) essential oil against canine skin-infection pathogens. Veterinary World. https://pubmed.ncbi.nlm.nih.gov/38680153/
- Sharma A, et al. (2021). The genus Nepeta: traditional uses, phytochemicals and pharmacological properties. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/33307050/
