Spearmint Oil: Evidence, Safety and How It Is Used
Spearmint oil is a carvone-rich mint oil, different from menthol-rich peppermint. What the few small trials found, and the safety points sources do and do not cover.
Content last updated . This page has not been medically reviewed.
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Safety first. This page is about smelling spearmint oil or, as a few trials used it, applying it in a studied form. It is not advice to swallow any essential oil. The sources we read for this oil say little about harms, so a lack of warnings here is not proof of safety. For a swallowing accident, call Poison Help at 1-800-222-1222 (US); call 911 for collapse, seizure or trouble breathing.
Which plant and part
Spearmint is Mentha spicata L. (Lamiaceae), an accepted name in GBIF. [1] One composition study analyzed oil from the aerial parts of the plant, meaning the parts above ground. [2] Do not mix it up with peppermint, which is Mentha × piperita; see peppermint oil and the plant pages for spearmint and peppermint versus spearmint. Spearmint tea is a different product, covered under spearmint tea.What is in it: carvone versus menthol
The main parts of one analyzed M. spicata oil were carvone (67.8%) and limonene (10.6%). [2] The same study described three chemotypes of spearmint oil in published data: carvone-rich, carvone with trans-carveol, and pulegone with menthone. [2] So "spearmint oil" can differ by source, and a label with the botanical name and a test report matters; see reading an essential oil label. The sources we read for spearmint do not give a menthol figure, so we do not compare menthol levels. For peppermint, NCCIH says menthol should not be inhaled by or applied to the face of an infant or small child. [3] Whether the same applies to spearmint oil is not described in the sources we read.Traditional use
Traditional use of spearmint oil by named peoples or periods is not described in the sources we read. Traditional use would not prove benefit. See what traditional use can and cannot tell us.What research shows
Human research on spearmint oil is sparse. Both trials below are small and have design limits.| Question | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Nausea after chemotherapy | A randomized, double-blind trial reported fewer and less intense vomiting episodes in the first 24 hours with spearmint or peppermint oil than with the previous anti-nausea regimen alone, and no adverse effects reported. [4] | Promising but limited (one small trial) | Chemotherapy courses (50 analyzed per group); the summary we read does not state how the oil was applied |
| Acne | A topical solution of a root extract plus spearmint oil lowered lesion counts, but did not differ significantly from 1% clindamycin solution. [5] | Insufficient evidence for spearmint oil itself | 60 people with mild to moderate facial acne; 4 weeks; mixture with another plant |
| Nausea mechanism | A review says M. spicata shows serotonin-blocking activity, and that more high-quality studies are needed to confirm clinical effectiveness and safety. [6] | Preclinical mechanism, human evidence thin | Review |
Reading these honestly: the acne trial tested a mixture, so it cannot say what spearmint oil did on its own. The nausea trial had spearmint and peppermint groups, and its summary does not say how the oil was applied, so it cannot guide anyone's use. See essential oils for nausea and essential oils for skin, acne and eczema.
Proper evidence not found: we searched PubMed for spearmint oil trials on anxiety, memory and sleep and found no usable human trials. Findings on peppermint oil do not transfer to spearmint oil.
Safety
- Skin: the FDA says many plants contain materials that can irritate or cause allergic reactions on the skin. [7] The allergy sources we read did not name spearmint oil.
- Medicines, pregnancy and breastfeeding, children, liver and kidney, surgery: not described for spearmint oil in the sources we read. Ask a pharmacist or clinician; see medicine interactions, pregnancy and breastfeeding and children and teens. Tell a surgical team about oils you use.
- Cancer care: the nausea trial was in people on chemotherapy. Anyone having cancer treatment should ask their oncology team before using any product.
- Pets: see essential oils and pets.
Frequently asked questions
Is spearmint oil the same as peppermint oil?
No. They come from different mint species, and the analyzed spearmint oil was mostly carvone. [2]
Does spearmint oil help nausea?
One small trial in people having chemotherapy reported less vomiting with spearmint or peppermint oil, but the summary does not describe how it was applied, so we cannot translate it into advice. [4]
Does spearmint oil treat acne?
A trial of a mixture of a root extract and spearmint oil found acne lesions fell, about as much as clindamycin solution did, but the trial cannot isolate spearmint oil. [5]
Can children or babies be exposed to menthol-rich mint oils?
NCCIH says menthol in peppermint oil should not be inhaled by or applied to the face of an infant or small child. [3] The sources we read do not say the same for spearmint oil.
Is it safe to swallow spearmint oil?
This site does not advise swallowing essential oils. For an accident, call Poison Help at 1-800-222-1222 (US).
References
- GBIF Secretariat. Mentha spicata L., GBIF Backbone Taxonomy. Name checked through the GBIF species match service. Read 2026-10-22.
- Isfendiyaroglu H et al. Chemical characterization of the essential oil compositions of Mentha spicata and M. longifolia ssp. cyprica from the Mediterranean Basin. Molecules. 2024. PubMed 38731461. Read 2026-10-22.
- National Center for Complementary and Integrative Health (NIH). Peppermint Oil: Usefulness and Safety. Read 2026-10-22.
- Tayarani-Najaran Z et al. Antiemetic activity of volatile oil from Mentha spicata and Mentha x piperita in chemotherapy-induced nausea and vomiting. Ecancermedicalscience. 2013. PubMed 23390455. Read 2026-10-22.
- Saeidi S et al. Evaluation of the effectiveness of Berberis integerrima Bunge root extract combined with spearmint essential oil in the treatment of acne vulgaris: a randomized controlled clinical trial. J Cosmet Dermatol. 2024. PubMed 38545754. Read 2026-10-22.
- Rajabalizadeh R et al. Medicinal herbs in treating chemotherapy-induced nausea and vomiting: a review. Phytother Res. 2022. PubMed 35841194. Read 2026-10-22.
- U.S. Food and Drug Administration. Aromatherapy. Read 2026-10-22.