Tea Tree Oil : Dosing and Safety

by MedlinePlus

(Page 2 of 2)

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. The International Organization for Standardization has specified limits for 14 of the almost 100 ingredients that make up tea tree oil. By this standard, tea tree oil must contain terpinolene 1.5-5%, 1,8-cineole ≤15%, α-terpinene 5-13%, γ-terpinene 10-28%, p-cymene 0.5-12%, terpinen-4-ol ≥30%, α-terpineol 1.5-8%, limonene 0.5-4%, sabinene trace 3.5%, aromadendrene trace 7%, δδ-cadinene trace 8%, globulol trace 3%, viridiflorol trace 1.5%, and α-pinene 1-6%. Prior to the development of the international standard (ISO 4730), an Australian standard existed (AS2782-1985) which required tea tree oil preparations to contain >30% terpinene-4-ol and <15% 1,8-cineole <15%.

Adults (18 years and older)

Note: Recommended doses are based on those used in studies. These doses have not necessarily been proven effective or safe. While 100% tea tree oil is sometimes used, it is often diluted with inactive ingredients. Due to reports of severe side effects after tea tree oil ingestion, it is strongly recommended that tea tree oil not be taken by mouth. Although tea tree oil solution has been used as a mouthwash, it should not be swallowed.

Acne: Tea tree oil 5% gel, applied to acne-prone areas of the skin daily.

Athlete's foot (tinea pedis): 10% tea tree oil cream, applied twice daily to the feet after they have been thoroughly washed and dried or 25-50% tea tree oil solution applied twice daily to the affected area for 4 weeks.

Burns: It is recommended that tea tree oil products not be used on burn wounds due to the cytotoxicity of tea tree oil on human skin cells.

Dandruff: 5% tea tree oil shampoo daily for at least 4 weeks has been used.

Fungal nail infection (onychomycosis): 100% tea tree oil, applied to the affected area twice daily for six months.

Genital Herpes: 6% tea tree oil gel has been used.

MRSA: 4% tea tree oil nasal ointment and 5% tea tree oil body wash has been used.

Thrush: Alcohol-based or alcohol-free solution four times daily for 2 to 4 weeks

Children (younger than 18 years)

There is insufficient research to recommend the safe use of tea tree oil in children.

Safety

Allergies

There are multiple reports of allergy to tea tree oil when taken by mouth or used on the skin. Skin reactions range from mild contact dermatitis to severe blistering rashes. People with a history of allergy to tea tree oil ( Melaleuca alternifolia ), to any of its components, or to plants that are members of the Myrtle ( Myrtaceae ) family, balsam of Peru or benzoin, should not use tea tree oil. People with a history of allergy to tincture of benzoin or colophony (rosin) should not use tea tree oil products because cross-reactions have been reported. There is a case report of a patient with linear IgA disease, a subepidermal blistering disorder which can be precipitated by contact with tea tree oil.

Use cautiously if allergic to eucalyptol as many tea tree preparations contain eucalyptol.

Side Effects and Warnings

Tea tree oil taken by mouth is associated with potentially severe reactions, even when used in small quantities. Several reports describe people using tea tree oil by mouth who developed severe rash, reduced immune system function, abdominal pain, diarrhea, lethargy, drowsiness, inflammation of the corners of the mouth, slow or uneven walking, confusion, or coma. There have also been reports of nausea, unpleasant taste, burning sensation, and bad breath associated with tea tree oil use. Many tea tree preparations contain large volumes of alcohol.

When used on the skin, tea tree oil may cause allergic rash, redness, blistering, and itching. Use of tea tree oil inside of the mouth or eyes can cause irritation. One report describes a person with long-standing eczema (atopic dermatitis) who developed a severe flare after applying 100% tea tree oil mixed in honey to the skin. Animal research suggests that tea tree oil used on the skin in large quantities can cause serious reactions such as difficulty walking, weakness, muscle tremor, slowing of brain function, and poor coordination. When applied in the ears of animals, 100% tea tree oil has caused reduced hearing, although a 2% solution has not led to lasting changes in hearing. The effect of tea tree oil on hearing when used in the ears of humans is not known.

Pregnancy and Breastfeeding

Not enough scientific information is available to recommend tea tree oil during pregnancy or breastfeeding. Animal studies suggest caution in the use of tea tree oil during childbirth because tea tree oil has been reported to decrease the force of spontaneous contractions, which theoretically could put the baby and mother at risk. Women who are breastfeeding should not apply tea tree oil to the breast or nipple since it may be absorbed by the infant.

Interactions

Interactions with Drugs

Tea tree oil skin products may result in drying of the skin, and may worsen the drying caused by skin treatments such as tretinoin (Retin-A®), benzoyl peroxide, salicylic acid, or isotretinoin (Accutane®, taken by mouth).

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