What is it's use?

Proponents believe tea tree oil is an antiseptic and use it to fight germs. It has been used to treat cuts, minor burns, athlete's foot, and insect bites. Some claim it can treat bacterial and fungal skin infections, wound infections, gum infections, acne, head lice, eczema, vaginal yeast infections, colds, pneumonia, and other respiratory illnesses.

Although no one claims tea tree oil can prevent or treat cancer, some proponents claim the oil can boost the immune system. Some herbalists claim that tea tree oil can be used as a "lymphatic recharge" for a "sluggish" lymphatic system. Available scientific evidence does not support these claims.

Household cleaners that contain tea tree oil have also been promoted as alternatives to products that contain cancer-causing chemicals, such as formaldehyde.

What does it involve?

Tea tree oil can be dissolved in water or used at full strength. It is also available in the form of ointments, creams, lotions, and soap. Tea tree oil is often sold in dark glass bottles to prevent light from affecting its potency. When used to treat infections and skin conditions, the oil can be applied directly to the skin in full strength or diluted form using cotton swabs. The oil can also be found in deodorants, shampoos, soaps, antiseptic first-aid creams, cosmetics, and household cleaning products.

Tea tree oil should never be taken internally. For colds and other respiratory illnesses, the oil is added to a vaporizer so that the mist can be inhaled. Drops of the oil can be added to bath water. The oil is sometimes mixed in water as a mouthwash.

What is the history behind it?

The aborigines of Australia were the first to discover the healing properties of tea tree oil thousands of years ago. They treated cuts, burns, and skin infections by crushing the leaves of the tree and applying them to cuts and injuries. In the 1770s, the British explorer Captain Cook observed the native Australians brewing tea from the leaves. He then brewed tea of his own to give to his crew to prevent scurvy. He coined the name tea tree.

In the 1920s, Australian physicians began to use the oil to clean wounds and prevent infections after surgery. They believed it to be more effective than carbolic acid, the antiseptic most used at that time. Average Australians then began to use the oil as a household remedy for skin conditions and fungus infections. During World War II, tea tree oil was included in the first-aid kits given to all Australian soldiers and sailors.

After the discovery of penicillin and other antibiotics in the late 1940s, tea tree oil went out of favour as an antiseptic until the 1980s, when it was discovered that some bacteria were resistant to certain antibiotics, such as methicillin and vancomycin. Today, there is renewed interest in tea tree oil as an alternative to these antibiotics for skin infections.

What is the evidence?

Recent laboratory experiments suggest that tea tree oil holds promise as an antiseptic when used on the skin to kill germs, including those that are resistant to methicillin, vancomycin, and other antibiotics. Other laboratory studies suggest that tea tree oil might be helpful against scabies (skin mites) and some types of fungus. A laboratory study published in 2006 showed that tea tree oil can kill yeasts that cause mouth infections of cancer patients with weakened immune systems. However, the safety and effectiveness of tea tree oil has not been tested in clinical studies of cancer patients with mouth infections, and the fact that tea tree oil is toxic when swallowed seems likely to limit its use in mouth infections. Even though laboratory studies may show promise, further studies are needed to find out whether the results apply to humans.

A few human studies have been done on tea tree oil’s effectiveness in treating various conditions. In studies to determine whether tea tree oil helped fungal toenail infections, it compared well to clotrimazole cream, an older treatment. However, the testing procedure was scientifically somewhat weak. Tests to find out whether tea tree oil helped prevent cold sores showed no benefit, but the tests also had some design flaws that could have affected the results. Tea tree oil has also been tested to see whether it helped mild acne. It was compared to benzoyl peroxide for 3 months, and both groups showed similar improvement by the end of the study. Tests to see whether it cured athlete’s foot showed mixed results. Despite years of use, available clinical evidence does not support the effectiveness of tea tree oil for treating skin problems and infections in humans.