Tea tree oil is toxic

Tea tree oilDrug groupsTea tree oil is an essential oil made from the leaves and branch tips of the Australian tea tree Melaleuca alternifolia and related trees. It has antimicrobial and anti-inflammatory properties and is characterized by its broad spectrum of activity against bacteria, fungi, viruses and parasites. Tea tree oil and corresponding preparations can be administered for the external treatment of various infectious and parasitic diseases. Possible adverse effects include local irritation and allergic reactions. Diluted preparations cause fewer side effects than concentrated ones. Tea tree oil should not be ingested because it can lead to poisoning.

synonym: Melaleucae aetheroleumPhEur, Melaleucae alternifoliae aetheroleum, Tea Tree Oil, TTO


The pure tea tree oil is available in pharmacies and drug stores. There are many products on the market containing the essential oil, such as personal care products, lip balm, mouthwashes and toothpastes. As a rule, these are not registered drugs.

Structure and properties

Tea tree oil is obtained by steam distillation from the leaves and branch tips of Melaleuca alternifolia, Melaleuca linariifolia, Melaleuca dissitiflora and / or others Melaleuca-Types of Extracted Essential Oil.

The Australian tea tree Melaleuca alternifolia is a small tree or shrub about three to six meters high that is native to the coast of New South Wales and Queensland in Australia and has long been used by the Aborigines. Like the eucalyptus, it belongs to the myrtle family (Myrtaceae). Tea tree oil has been used since the 1920s.

Tea tree oil is a clear, easily mobile, colorless to pale yellow and volatile liquid with a characteristic, intensely aromatic odor that is practically insoluble in water. The more than one hundred ingredients mainly include isoprenoids and, in particular, cyclic monoterpenes, sesquiterpenes and the corresponding alcohols. Terpinen-4-ol, 1,8-cineol, γ-terpinene and α-terpinene are representatives that occur in high concentrations in oil.


Tea tree oil has antiseptic, antimicrobial, antioxidant, and anti-inflammatory properties. It is bactericidal against gram-positive and gram-negative pathogens, fungicidal, antiviral and anti-parasitic.

The sensitive pathogens include, for example, streptococci and staphylococci, Pseudomonas aeruginosa, Candida albicans, Dermatophytes, the herpes simplex virus, itch mites, lice and trichomonads. The effects are based, among other things, on a disruption of the structure and integrity of the cell membrane.

application areas

Possible areas of application include (examples):


According to the instructions for use. The dosage depends on the area of ​​application. For the majority of the indications, dilutions are used, for example with water, alcohol or almond oil. Examples of the preparation can be found in Reichling et al. (2003).


Tea tree oil is contraindicated in case of hypersensitivity. It must not be ingested and should not get in the eyes. We do not have a complete list of precautionary measures.

unwanted effects

Possible adverse effects include local and allergic reactions, including allergic contact dermatitis. Irritation occurs especially when undiluted oil or highly concentrated agents are used.

Tea tree oil is toxic when taken orally and can cause symptoms such as vomiting, diarrhea, confusion, incoordination, hallucinations, and a coma. Fortunately, no deaths have been reported so far.

  • Carson C.F., Hammer K.A., Riley T.V. Melaleuca alternifolia (Tea Tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev, 2006, 19 (1), 50-62 Pubmed
  • Carson C.F., Riley T.V., Cookson B.D. Efficacy and safety of tea tree oil as a topical antimicrobial agent. J Hosp Infect, 1998, 40 (3), 175-8 Pubmed
  • de Groot AC, Schmidt E. Tea tree oil: contact allergy and chemical composition. Contact Dermatitis, 2016 Pubmed
  • European Pharmacopoeia PhEur
  • Instructions for use
  • Hammer K.A., Carson C.F., Riley T.V., Nielsen J.B. A review of the toxicity of Melaleuca alternifolia (tea tree) oil. Food Chem Toxicol, 2006, 44 (5), 616-25 Pubmed
  • Hartford O., Zug K.A. Tea tree oil. Cutis, 2005, 76 (3), 178-80 Pubmed
  • Pazyar N., Yaghoobi R., Bagherani N., Kazerouni A. A review of applications of tea tree oil in dermatology. Int J Dermatol, 2013, 52 (7), 784-90 Pubmed
  • Reichling J., Iten F., Saller R. Australian tea tree oil (Melaleuca aetheroleum). Phytotherapy, 2003, 2, 32-39
  • Safety data sheet (CH)

Conflicts of Interest: None / Independent. The author has no relationships with the manufacturers and is not involved in the sale of the products mentioned.

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This article was last changed on 7/31/2016.
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