Does Peppermint Oil Repel Mosquitoes? Studies vs the CDC List
Lab studies have reported peppermint oil keeping mosquitoes off for hours, and CDC still does not list it as a repellent to rely on where mosquitoes carry disease. Both statements are true, and the gap between them is the whole subject of this article. A scent can show an effect in a cage and still not be a product that has been evaluated for protecting a person outdoors. We sell peppermint oil as a fragrance material, we sell no repellent, and nothing here is a claim that our oils repel anything.
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Shop Now →What the studies tested
Each row says what was done and what the report does not give. All were laboratory or small-volunteer studies of the mosquito Aedes aegypti unless noted, and none tested our oils.
| Study | Material and design | Reported result | What it does not show |
|---|---|---|---|
| Kumar et al., Asian Pac J Trop Biomed, 2011 | Mentha piperita leaf oil; larvae in water, and a human-bait test with adult Aedes aegypti | Larvae: LC50 111.9 ppm and LC90 295.18 ppm at 24 hours. Human bait: 100% protection from adult bites for 150 minutes | The abstract does not give the oil concentration on skin or the number of volunteers |
| Lalthazuali and Mathew, Parasitol Res, 2017 | 20% oil in ethanol (M. piperita and two other oils) against 20% DEET in ethanol; 3 to 5 day old female Aedes aegypti | No landing observed for up to 6 hours for the 20% M. piperita, as for DEET; a 5% blend of four oils matched too | The abstract gives no replicate count; the figure is for 20% oil in ethanol |
| Mitra et al., J Med Entomol, 2020 | 21 ingredients from the EPA 25(b) list and 5 commercial sprays containing only 25(b) ingredients, in a Y-tube olfactometer | Five oils reduced attraction to human odour, peppermint among them. Of the five commercial sprays, one reduced attraction, for up to 30 minutes | An olfactometer measures choice in a tube, not bites on a person; four of five commercial sprays did nothing in it |
| Trongtokit et al., Phytother Res, 2005 | 38 essential oils on forearm skin, 0.1 ml per 30 cm2, at 10%, 50% and undiluted; Aedes, then Culex and Anopheles | At 10% or 50%, no oil prevented bites for 2 hours. Undiluted citronella, patchouli, clove and makaen gave 2 hours of complete repellency | Peppermint is not among the oils the abstract reports |
| Fradin and Day, N Engl J Med, 2002 | 15 volunteers, 16 products including 7 botanical repellents, arm-in-cage | 23.8% DEET: 301.5 minutes average complete protection. A soybean-oil repellent: 94.6 minutes. IR3535: 22.9 minutes. Other botanical products: under 20 minutes each | The abstract does not name a peppermint product; these were commercial products of that date |
Read together, the studies disagree. The two reports that tested peppermint on skin or bait found hours of protection under their conditions; the study that put 38 oils on volunteers at 10% and 50% found none that stopped bites for two hours, and the volunteer trial of commercial botanicals found under 20 minutes for most. The studies differ in species, concentration, vehicle and endpoint, and in whether the endpoint is landing, biting or choice in a tube. That is the reason no single number from the first two rows should be carried into a purchase decision.
The concentration problem, in arithmetic
The 6-hour result in the table is for oil at 20% in ethanol. Our own safety copy says to dilute to 0.5% to 2% in a carrier oil and patch test first. The Cosmetic Ingredient Review report records a highest cosmetic use level of 5% for peppermint oil in face and neck leave-on products (2017), and a maximum dermal level of 5.4% attributed to Tisserand and Young (CIR, 2018; the 5.4% is a secondary figure there). So 20% is:
- ten times the top of our 0.5% to 2% copy (20 / 2);
- four times CIR's 5% highest use level (20 / 5);
- about 3.7 times the 5.4% dermal figure (20 / 5.4).
In a 10 ml roller bottle (a container, not something we sell), 20% is 2 ml of oil, about 40 drops at 20 drops per ml, against 0.2 ml, about 4 drops, at 2%. We do not suggest making a 20% skin product from either of our oils. At the strengths we do stand behind, the studies above tell you nothing, because none tested them; the 5% blend in the Lalthazuali study mixed four oils, so it cannot be read as 5% peppermint.
What CDC and EPA say
CDC lists six active ingredients in EPA-registered repellents: DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol and 2-undecanone. It says it does not know the effectiveness of non-EPA-registered insect repellents, "including some natural repellents" (CDC), and that choosing a registered product means EPA has evaluated its effectiveness. Peppermint oil is not on the CDC list.
Peppermint oil does appear, with cornmint oil, in the federal minimum-risk exemption, 40 CFR 152.25(f) (Cornell LII). Products under it may not bear claims to control insects carrying specific diseases. EPA says it is considering removing personal mosquito and tick repellents from the exemption, with a transition of up to five years (EPA). The Mitra study's own result fits that picture: one of five commercial 25(b) sprays showed an effect, and only up to 30 minutes.
Our verdict
- Where mosquitoes carry disease (Aedes mosquitoes transmit dengue, chikungunya, Zika and yellow fever, per the Mitra abstract), use a repellent from the CDC list, and ask a physician or travel clinic about your destination. Do not substitute an essential oil.
- For a backyard evening, the same list applies if you want an evaluated product.
- If you like the smell, a diffuser or a diluted skin blend is a fragrance choice. We make no claim that it protects you, and a lab result at 20% is not a reason to raise the dilution.
- Children: the NCCIH says menthol should not be applied to the face of an infant or small child because it may affect breathing (NCCIH, May 2025). Ask a paediatrician or pharmacist about repellents for children.
- Pets: ask a veterinarian before using any essential oil around cats or dogs; our cat guide explains why.
For the dilution rules behind our 0.5% to 2% copy, see the safety basics. For indoor pests other than mosquitoes, around the house and the bed bug article take their own angles.
In short: the laboratory results are real but narrow, the registered list exists for a reason, and a bottle of fragrance oil is not a substitute for it.
Peppermint Essential Oil
Peppermint Essential Oil from our own shop, in sizes from 0.5 oz to bulk.
From $10.99
Shop Now →Sources & Further Reading
- Kumar S, Wahab N, Warikoo R, 2011. Bioefficacy of Mentha piperita essential oil against dengue fever mosquito Aedes aegypti L. Asian Pac J Trop Biomed 1(2):85-88. PMID 23569733
- Lalthazuali, Mathew N, 2017. Mosquito repellent activity of volatile oils from selected aromatic plants. Parasitol Res 116(2):821-825. PMID 28013374
- Mitra S et al., 2020. Efficacy of active ingredients from the EPA 25(B) list in reducing attraction of Aedes aegypti to humans. J Med Entomol 57(2):477-484. PMID 31612914
- Trongtokit Y et al., 2005. Comparative repellency of 38 essential oils against mosquito bites. Phytother Res 19(4):303-309. PMID 16041723
- Fradin MS, Day JF, 2002. Comparative efficacy of insect repellents against mosquito bites. N Engl J Med 347(1):13-18. PMID 12097535
- CDC. Preventing mosquito bites. cdc.gov/mosquitoes/prevention
- US EPA. Personal insect repellents and minimum risk pesticides. epa.gov
- 40 CFR 152.25. law.cornell.edu/cfr/text/40/152.25
- Cosmetic Ingredient Review, 2018. Amended Safety Assessment of Mentha piperita (Peppermint)-Derived Ingredients. cir-safety.org
- NCCIH (NIH), 2025. Peppermint Oil: Usefulness and Safety. nccih.nih.gov