Health Care Professional Information

Scientific Name
Melaleuca alternifolia
Common Name

Tea tree, ti tree

Clinical Summary

Tea tree oil is an essential oil distilled from the leaves of Melaleuca alternifolia, a plant native to Australia. It has been used in traditional medicine to treat colds, cough and skin infections.
The medicinal properties of tea tree oil were first reported in the 1920s. Its antiseptic effects were found to be several fold greater than phenol, a compound that was used extensively at the time to prevent infections. Following this discovery, tea tree oil was incorporated in many topical formulations to treat cutaneous infections and to accelerate wound healing. It is also found as an ingredient in skin and hair products.

In vitro studies indicate wide spectrum antimicrobial (2) (12), antiviral (20), antiprotozoal (21), anti-inflammatory (22) and antiproliferative (14) (15) properties.
Topical application of tea tree oil was shown to have cytotoxic effects in mice bearing subcutaneous tumors (23).
Clinical studies suggest its efficacy in treating acne (5), tinea pedis (6) (9), distal subungual onychomycosis (7), histamine-induced skin inflammation (8), dandruff (10), warts (16), cold sores (11) and experimental contact dermatitis (18).
A systematic review found that aromatherapy with tea tree oil led to reductions in anxiety and depression scores, improved sleep and resulted in an overall increase in well-being in cancer patients (24).

Purported Uses
  • Acne
  • Burns
  • Cold sores
  • Eczema
  • Fungal infections
  • Inflammation
  • Insect bites and stings
  • Mucositis
  • Skin infections
  • Wound healing
Constituents
  • Monoterpenes: alpha-Terpinene, para-Cymene, (+)-Limonene, gamma-Terpinene, alpha-Terpinolene, Sabinene
  • Sesquiterpenes: Aromadendrene, gamme-Cadenene
  •  Alcohols: Terpinen-4-ol, 1,8-Cineole, alpha-Terpineol, Globulol
    (1)
Mechanism of Action

Terpinen-4-ol, a major constituent of tea tree oil, was shown to have antimicrobial activity against Candida albicans, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. In addition, terpin-4-ol, alpha-terpineol, and alpha-pinene were found to possess antimicrobial effects against Staphylococcus epidermidis and Propionibacterium acnes (2). Terpinen-4-ol has also been shown to suppress inflammatory mediator production by activated human monocytes (8).
A tea tree oil concentrate prevented influenza virus from entering the host cells by disturbing the normal viral membrane fusion procedure (25).
In vitro studies indicate that tea tree oil has weak estrogenic and antiandrogenic properties that may alter the estrogen and androgen signaling pathways (13).

Skin irritation following use of tea tree oil is due to auto-oxidation of tea tree oil, and via formation of epoxide intermediates resulting from arene-epoxidation reactions catalyzed by human cytochrome P450 enzymes (17).

Adverse Reactions

Reported (topical): Local skin irritation and allergic contact dermatitis(3) (19)
Reported (oral): Disorientation, systemic contact dermatitis, coma, body rash, and neutrophil leukocytosis (4)
Reported (topical): Repeated application of lavender and tea tree oils resulted in gynecomastia in prepubertal boys (13).

Dosage (Inside MSKCC Only)
This field is only visible to only OneMSK users.
References
  1. Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (Tea Tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev. 2006 Jan; 19(1):50-62.
  2. May J, et al. Time-kill studies of tea tree oils on clinical isolates. J Antimicrob Chemother 2000;45:639-43.
  3. Rubel DM, Freeman S, Southwell IA. Tea tree oil allergy: what is the offending agent? Report of three cases of tea tree oil allergy and review of the literature. Australia J Dermatol 1998;39:244-7.
  4. Carson C, Riley TV, Cookson BD. Efficacy and safety of tea tree oil as a topical antimicrobial agent. J Hosp Infect 1998;40:175-8.
  5. Bassett IB, Pannowitz DL, Barnetson RS. A comparative study of tea tree oil versus benzol peroxide in the treatment of acne. Med J Aust 1990;153:455-8.
  6. Tong MM, Altman PM, Barnetson RS. Tea tree oil in the treatment of tinea pedis. Australia J Dermatol 1992;33:145-9.
  7. Buck DS, Nidorf DM, Addino JG. Comparison of two topical preparations for the treatment of onychomycosis: Melaleuca alternifolia (tea tree) oil and clotrimazole. J Fam Pract 1994;38:601-5.
  8. Koh KJ, et al. Tea tree oil reduces histamine-induced skin inflammation. Br J Dermatol 2002;147:1212-7.
  9. Satchell AC, et al. Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: A randomized, placebo-controlled, blinded study. Australas J Dermatol 2002; 43: 175-8.
  10. Satchell AC, et al. Treatment of dandruff with 5% tea tree oil shampoo. J Am Acad Dermatol 2002; 47(6): 852-5.
  11. Carson CF, et al. Melaleuca alternifolia (tea tree) oil gel (6%) for the treatment of recurrent herpes labialis. J Antimicrob Chemother 2001; 48: 450-1.
  12. Bagg J, et al. Susceptibility to Melaleuca alternifolia (tea tree) oil of yeasts isolated from the mouths of patients with advanced cancer. Oral Oncol 2006; 42(5): 487-92.
  13. Henley DV, Lipson N, Korach KS, et al. Prepubertal gynecomastia linked to lavender and tea tree oils. N Engl J Med 2007;356(5):479-85.
  14. Calcabrini A, Stringaro A, Toccacieli L, et al. Terpinen-4-ol, the main component of Melaleuca alternifolia (tea tree) oil inhibits the in vitro growth of human melanoma cells. J Invest Dermatol. 2004 Feb;122(2):349-60.
  15. Greay SJ, Ireland DJ, Kissick HT, et al. Induction of necrosis and cell cycle arrest in murine cancer cell lines by Melaleuca alternifolia (tea tree) oil and terpinen-4-ol. Cancer Chemother Pharmacol. 2010 Apr;65(5):877-88.
  16. Millar BC, Moore JE. Successful topical treatment of hand warts in a paediatric patient with tea tree oil (Melaleuca alternifolia). Complement Ther Clin Pract. 2008 Nov;14(4):225-7.
  17. Meesters RJ, Duisken M, Hollender J. Cytochrome P450-catalysed arene-epoxidation of the bioactive tea tree oil ingredient p-cymene: indication for the formation of a reactive allergenic intermediate? Xenobiotica. 2009 Sep;39(9):663-71.
  18. Wallengren J. Tea tree oil attenuates experimental contact dermatitis. Arch Dermatol Res. 2011 Jul;303(5):333-8.
  19. Posadzki P, Alotaibi A, Ernst E. Adverse effects of aromatherapy: a systematic review of case reports and case series. Int J Risk Saf Med. 2012 Jan 1;24(3):147-61.
  20. Li X, Duan S, Chu C, et al. Melaleuca alternifolia Concentrate Inhibits in Vitro Entry of Influenza Virus into Host Cells. Molecules. 2013 Aug 9;18(8):9550-66.
  21. Mikus J, Harkenthal M, Steverding D, Reichling J. In vitro effect of essential oils and isolated mono- and sesquiterpenes on Leishmania major and Trypanosoma brucei. Planta Med. 2000 May; 66(4):366-8.
  22. Ninomiya K, Hayama K, Ishijima SA, et al. Suppression of inflammatory reactions by terpinen-4-ol, a main constituent of tea tree oil, in a murine model of oral candidiasis and its suppressive activity to cytokine production of macrophages in vitro. Biol Pharm Bull. 2013;36(5):838-44.
  23. Ireland DJ, Greay SJ, Hooper CM, et al. Topically applied Melaleuca alternifolia (tea tree) oil causes direct anti-cancer cytotoxicity in subcutaneous tumour bearing mice. J Dermatol Sci. 2012 Aug;67(2):120-9.
  24. Boehm K, Büssing A, Ostermann T. Aromatherapy as an adjuvant treatment in cancer care - a descriptive systematic review. Afr J Tradit Complement Altern Med. 2012 Jul 1;9(4):503-18.
  25. Li X, Duan S, Chu C, et al. Melaleuca alternifolia concentrate inhibits in vitro entry of influenza virus into host cells. Molecules. 2013 Aug 9;18(8):9550-66.

Consumer Information

How It Works

Bottom Line: Tea tree oil may be effective in treating certain skin conditions.

Tea tree oil is the essential oil distilled from Melaleuca alternifolia, a plant native to Australia. In laboratory tests, tea tree oil effectively killed a number of the bacteria and fungi most commonly found in skin infections and acne, including Candida albicans, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis and Propionibacterium acnes. Tea tree oil was also found effective against some cancer cells in the laboratory.
In healthy volunteers, a tea tree oil extract was able to reduce inflammation caused by histamine injections. It was also shown to be effective in individuals with athlete's foot, acne, cold sores and warts.

Purported Uses
  • To treat acne
    One clinical trial showed that tea tree oil was as effective as benzoyl peroxide in treating acne.
  • To treat minor burns
    No scientific evidence supports this use.
  • To treat fungal infections of the skin, fingernails, toenails
    A clinical trial showed that tea tree oil was as effective as antifungal medicines against fingernail/toenail fungal infections. However, studies produced mixed results when used to treat fungal infections of the foot.
  • To reduce inflammation
    Tea tree oil reduced inflammation caused by histamine injections in healthy volunteers.
  • To treat insect bites and stings
    Tea tree oil can reduce inflammation.
  • To treat mucositis (swelling of the mucous membranes of the mouth)
    There are no clinical data to prove this claim. Intake of tea tree oil by mouth can cause severe toxicity.
  • To treat dandruff
    A clinical trial showed that tea tree oil is effective in controlling dandruff.
  • To treat cold sores
    A small study showed possible benefits, but further study is necessary.
Side Effects
  • When used topically, local skin irritation and/or an allergic reaction (contact dermatitis: itching, redness, and swelling) have been reported.
  • Repeated application of lavender and tea tree oils resulted in gynecomastia (enlargement of breast tissue) in prepubertal boys.
  • Oral use can cause disorientation, systemic contact dermatitis, coma, body rash, and neutrophil leukocytosis.
E-mail your questions and comments to aboutherbs@mskcc.org.