Peppermint vs Eucalyptus Oil
Peppermint and eucalyptus oil compared: what each is, what regulators and trials found, and why both need extra care around babies, young children and swallowing.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read essential oil safety before you use anything on this page.
Urgent warning first. Poison Control says that if swallowed, eucalyptus oil can cause seizures. [1] A study in Victoria, Australia, found eucalyptus oil was a leading agent associated with hospital admission for poisoning in children under five. [2] In a telephone survey of 109 parents and guardians, 74 percent of incidents involved access through a home vaporiser unit. [2] If anyone swallows either oil, call Poison Help at 1-800-222-1222 (US). Call 911 for collapse, a seizure or trouble breathing. See Poisoning: what to do first.
What each oil is
Peppermint oil is the essential oil from the aerial parts of the flowering plant Mentha x piperita L., which the EMA says is obtained by steam distillation. [3] [4] Eucalyptus oil is the essential oil from the leaves or terminal branches of Eucalyptus species rich in 1,8-cineole (also called eucalyptol), mainly Eucalyptus globulus Labill. [5] [6] Other pages: Peppermint oil and Eucalyptus oil.What research found
Peppermint (promising but limited, mostly capsules). NCCIH says a small amount of research suggests enteric-coated peppermint oil capsules may improve irritable bowel symptoms in adults, and inhaled peppermint oil may reduce nausea and vomiting in people having chemotherapy. [7] Those are pharmaceutical-type capsules and inhalation trials, not advice to swallow oil. NCCIH says there is not enough evidence to reach conclusions for other conditions. [7]Eucalyptus (insufficient evidence for the oil itself). The EMA's eucalyptus summary relies on traditional use and notes that its trials tested 1,8-cineole, not the oil. [5] We found no systematic review of eucalyptus oil aromatherapy in the sources we read. Proper evidence not found (searched: NCCIH, EMA, PubMed).
Head-to-head. In one randomized experiment, 106 healthy people received nebulized peppermint, eucalyptus or rosemary oil, or no treatment. None of the oils changed spirometry (lung function tests), and the authors concluded people's sense of an effect was mediated at least partly by expectations. [8] In a 100-child dental trial, peppermint aromatherapy reduced anxiety but less than chamomile or lavender. [9] Neither study shows that either oil treats a cold or a lung condition.
Frequently asked questions
Is peppermint or eucalyptus oil better for congestion?
Not shown. The EMA accepted both for cough and cold on the basis of long-standing use only, and said firm conclusions about breathing could not be drawn. [3] [5]
Did either oil improve breathing tests?
Not in the one healthy-volunteer experiment we read: neither peppermint nor eucalyptus changed spirometry. [8]
Can I put either oil on a baby's chest or face?
NCCIH says menthol should not be inhaled by or applied to the face of an infant or small child. [7] The EMA says eucalyptus oil medicines must not be given to children under 30 months. [5]
Is eucalyptus oil dangerous if swallowed?
Yes. Poison Control says swallowed eucalyptus oil can cause seizures. [1] Call Poison Help at 1-800-222-1222 (US).
Which oil is safer around pets?
Not described in the sources we read. See essential oils and pets and ask a veterinarian.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
What regulators say (traditional use is not clinical proof)
| Question | Peppermint oil | Eucalyptus oil |
|---|---|---|
| EU herbal committee, cough and cold | Accepted on the basis of long-standing use, for inhaled and other forms. [3] | Accepted on the basis of long-standing use, for cough with the common cold. [5] |
| Other accepted uses | Oral preparations for minor belly spasms and pain, especially in irritable bowel syndrome, and skin application on forehead and temples for mild headache, described as well-established use. [3] | Localised muscle pain, on the basis of long-standing use. [5] |
| Strength of the clinical data the committee noted | For cough and cold, a possible effect in easing breathing was seen but firm conclusions could not be drawn. [3] | Studies in bronchitis and asthma used 1,8-cineole rather than the oil, so firm conclusions could not be drawn. [5] |
| Youngest age in the EU summary | Not for children under 2; cold and cough preparations not for ages 2 to 11. [3] | Not for children under 30 months, because of a risk of spasm of the larynx. [5] |
| Seizure history | Not to be used in children who have had seizures (for cold, muscle pain and itching uses). [3] | Must not be given to children with a history of seizures. [5] |
These are summaries of EU herbal medicines, not advice about bottled oil, and the committees' own summaries say to follow the package leaflet or ask a doctor or pharmacist. [3] [5]
Safety differences that matter
- Menthol and small children. NCCIH says menthol, which is in peppermint oil, should not be inhaled by or applied to the face of an infant or small child because it may negatively affect their breathing. [7] The EMA lists apnoea (interrupted breathing) and airway constriction in allergic patients among side effects of inhaled peppermint oil. [3]
- Eucalyptus poisoning. Case reports describe a 3-year-old with profound central nervous system depression within 30 minutes of swallowing eucalyptus oil, [10] and a 6-year-old who developed slurred speech and unconsciousness after widespread skin application of a home remedy containing it. [11] Poison Control adds that children have thin skin and immature livers. [1]
- Skin. NCCIH says peppermint oil on skin can cause rashes and irritation. [7] Eucalyptus skin reaction data are limited in the sources we read.
- Inhaled use. NCCIH calls inhaled peppermint oil possibly safe. [7] Safe inhaled levels of eucalyptus are not described in the sources we read.
- Pregnancy and breastfeeding. NCCIH says little is known about medicinal amounts of oral peppermint, and for the nipple area it says peppermint should be used only after breastfeeding and wiped off before the next feed. [7] Eucalyptus: not described in the sources we read.
- Medicines, liver and kidney. The EMA says peppermint oil medicines for belly problems must not be used in people with liver disease, gallstones or bile problems. [3] Ask a pharmacist; see how interactions work.
There is no universal winner. For children, pets and anyone with seizures, see peppermint oil safety: children, pets and menthol and essential oils around babies and children.
References
- Poison Control, Essential oils: Poisonous when misused. Read 2026-10-23.
- Aust N Z J Public Health 1997: Eucalyptus oil poisoning among young children. Read 2026-10-23.
- EMA, Peppermint oil summary (2020). Read 2026-10-23.
- GBIF Backbone, Mentha piperita. Read 2026-10-23.
- EMA, Eucalyptus oil summary (2016). Read 2026-10-23.
- GBIF Backbone, Eucalyptus globulus. Read 2026-10-23.
- NCCIH, Peppermint Oil (updated May 2025). Read 2026-10-23.
- Physiology & Behavior 2018: Inhaled peppermint, rosemary and eucalyptus essential oils do not change spirometry in healthy individuals. Read 2026-10-23.
- J Dent Sci 2025: Lavender, chamomile and peppermint inhalation aromatherapy on dental anxiety in children. Read 2026-10-23.
- Arch Dis Child 1980: Eucalyptus oil poisoning. Read 2026-10-23.
- Australas J Dermatol 1998: Topical eucalyptus oil poisoning. Read 2026-10-23.