Tea Tree
What is it? Overview Usage Side Effects and Warnings

What is Tea Tree?

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 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 foot and other fungal infections of the skin and nails. 2 One double-blind study found tea tree oil helpful for acne . 3 Another double-blind study found that tea tree oil gel may reduce gum inflammation in people with periodontal disease . 4 A single-blind study found evidence that tea tree oil may be helpful for dandruff . 5 Tea tree oil may be as effective as standard antiseptics for removing resistant strains...

Safety Issues

When used topically, tea tree oil is thought to be safe. However, it can cause allergic inflammation of the skin. 6 In addition, one report suggests that a combination of lavender oil and tea tree oil applied topically caused gynecomastia (breast enlargement) in three young boys. 7 The researchers who published this report also state that testing of tea tree oil revealed estrogenic (estrogen-like) and antiandrogenic (testosterone-blocking) effects. However, a literature search failed to find any other published reports that corroborate this claim.

Like other essential oils , tea tree oil can be toxic if taken orally in excessive doses.

Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been...