Captain Cook named this tree after finding that its aromatic, resinous leaves made a satisfying substitute for proper tea. One hundred and fifty years later, an Australian government chemist named A.R. Penfold studied tea tree leaves and discovered their antiseptic properties. Tea tree oil subsequently became a standard treatment in Australia for the prevention and treatment of wound infections. During World War II, the Australian government classified tea tree oil as an essential commodity and exempted producers from military service.

However, tea tree oil fell out of favor when antibiotics became widely available.

Tea tree oil can kill many bacteria, viruses, and fungi on contact.1,2,12 This makes it an antiseptic, like betadine, hydrogen peroxide, and many other essential oils. It is not an antibiotic in the common sense, because an antibiotic is absorbed throughout the body.

Preliminary double-blind studies suggest that tea tree oil might be useful for athlete's footand other fungal infections of the skin and nails.3,4,13

One double-blind study found tea tree oil helpful for acne.20

Another double-blind study found that tea tree oil gel may reduce gum inflammation in people with periodontal disease.15

A single-blind study found evidence that tea tree oil may be helpful for dandruff.14Tea tree oil plus lavender oil may also be an effective treatment for head lice.21

Tea tree oil may be as effective as standard antiseptics for removing resistant strains of staph bacteria from the skin of hospitalized patients.16-18Note: This does not mean tea tree oil is effective as an antibiotic for staph bacteria. It is an antiseptic. Antiseptics work on the surface of the body, while antibiotics work from within.

Additionally, tea tree oil has been proposed as a treatment for vaginal infections, thrush, and oral herpes(cold sores).1,6,7,12 However, there is no reliable evidence to indicate that it is effective for these purposes.