Thyme Oil
Thyme oil (Thymus vulgaris): what thymol and carvacrol are, the one inhalation trial we could read, what is not known about its safety, and why it is not for swallowing.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Safety first. Thyme oil is a concentrated essential oil. Poison Control says misuse of essential oils can cause serious poisoning and that many can cause rashes on skin. [1] We do not advise swallowing thyme oil. If a child or pet may have swallowed any essential oil, call Poison Help at 1-800-222-1222 (US); call 911 for collapse, a seizure or trouble breathing. [1] See Poisoning: what to do first.
What thyme oil is
Thyme oil is the concentrated aromatic oil of the thyme plant. It is not the same as thyme the kitchen herb, which is covered in Thyme (herbs and botanicals). A result for the herb, a tea or a food amount does not carry over to the oil.Which plant, which part
The accepted name on GBIF is Thymus vulgaris L., in the mint family (Lamiaceae). [2] A review of carvacrol names thyme (Thymus vulgaris) and oregano (Origanum vulgare) as plants whose essential oils contain carvacrol. [3] Many other Thymus species exist; the sources we read do not say which species or plant part each study used beyond what is stated below.Traditional use
Traditional use only, not proof: the sources we read for this page did not describe the traditional use of thyme oil, so we do not describe it. See the herb page for what sources say about thyme as a herb.What research shows
| Question | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Symptoms in hospitalized COVID-19 patients | In a randomized trial of 140 patients at one hospital, those who inhaled thyme oil three times a day for 5 days reported fewer symptoms than a control group that received routine treatment only; the authors recommended it as a non-pharmacological method. [4] | Promising but limited; control group had no placebo scent and outcomes were symptom-based | 140 adults in hospital, 70 per group; inhaled thyme oil, with no placebo scent described [4] |
| Carvacrol in people | A 2018 review of carvacrol (found in thyme and oregano oils) said human trials are still lacking. [3] | Preclinical (cells or animals) | Laboratory and animal work [3] |
| Colds, infections, skin, hair, pain | Proper evidence not found. We searched PubMed for thyme oil and thyme essential oil trials in people; the results were mostly laboratory, animal or livestock studies. | Insufficient evidence | Not applicable |
Smell is hard to blind, because people know whether they are smelling a strong oil, and symptom reports can be influenced by expectation. Inhaling an oil in a hospital trial does not show that a product at home is safe or useful. See Essential oils: what trials measure. Laboratory findings are not evidence of effect in people: human versus lab research.
Forms, and why the form matters
The trial above used inhaled thyme oil; the abstract does not give the product or amount. We give no dilution or amount. Thyme tea or thyme extract is a different product; see herbal teas and extracts.Frequently asked questions
Does thyme oil help with colds or coughs?
Proper evidence not found for colds. One hospital trial in COVID-19 patients reported fewer symptoms with inhaled thyme oil, but the control group had routine care only, with no placebo scent. [4]
What are thymol and carvacrol?
Carvacrol is a chemical found in thyme and oregano essential oils. [3] Human trials of carvacrol itself are lacking. [3]
Is thyme oil safe on skin?
Thyme-specific skin data were not found in the sources we read. Poison Control says many essential oils can cause rashes. [1]
Can I swallow thyme oil?
We do not advise swallowing any essential oil. Call Poison Help at 1-800-222-1222 after a swallowing incident. [1]
Is thyme oil the same as thyme tea?
No. They are different preparations, and results for one do not carry over to the other.
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.
Safety
- What is not known. We found no thyme-oil-specific source on skin reactions, medicines, pregnancy, breastfeeding, children, liver or kidney problems, or seizures. Lack of reports is not proof of safety.
- General essential oil cautions. Poison Control says many essential oils can cause rashes if used on the skin, advises not using them on damaged skin, and says allergic reactions with difficulty breathing are a medical emergency. [1] It also says essential oils may interact with medications and that children have thin skin and immature livers. [1] See strong oils and skin reactions and how interactions work.
- Quality. Poison Control says it can be hard to know what species, concentration or contaminants are in an essential oil bottle. [1] See reading an essential oil label.
- Surgery and pregnancy: tell the surgical team about any oil you use, and ask a clinician before use in pregnancy.
References
- Essential oils: Poisonous when misused (Poison Control). Read 2026-10-23.
- Thymus vulgaris L. (GBIF Backbone Taxonomy). Read 2026-10-23.
- Carvacrol and human health: A comprehensive review. Phytother Res 2018. Read 2026-10-23.
- The effects of aromatherapy with thyme oil on disease symptoms, vital findings, and hemodynamic parameters in COVID-19 patients. Explore (NY) 2024. Read 2026-10-23.