Tea tree oil (melaleuca oil) comes from a native Australian plant called Melaleuca alternifolia. Tea tree oil may have antiviral, antifungal, and antibacterial properties. It’s used for multiple purposes, such as smothering head lice, healing minor wounds, and controlling dandruff.

Tea tree oil is commercially available in varying strengths and as a strong volatile essential oil. It’s meant to be mixed with a carrier oil and used topically. It’s also an ingredient in products such as massage oil, shampoo, and shower gel. Its distinct, camphor-like scent is relaxing for some people.

Dandruff is a scalp condition, earmarked by dry, white flakes of dead skin. It’s sometimes accompanied by itching. Dandruff has several causes. These include:

  • oily, irritated skin
  • dry skin and hair
  • a fungus, called malassezia
  • contact dermatitis
  • poor hygiene

Tea tree oil’s moisturizing and antifungal properties may make it effective at alleviating some causes of dandruff.

Reduces yeast overgrowth on the scalp

Malassezia is a fungus, with yeast-like properties. It lives on everyone’s scalp in manageable quantities. In some people, malassezia can become overgrown. This may be due to poor hygiene habits, such as not shampooing often, or it may be the result of a medical condition. Either way, dandruff can result. A study indicated that shampoo with 5 percent tea tree oil was effective at reducing dandruff caused by the yeast Pityrosporum ovale (malassezia). Study participants used either tea tree oil shampoo, or a placebo, for one month. Tea tree oil shampoo users had a 41 percent reduction in dandruff severity.

Reduces itching and other dandruff symptoms

Tea tree oil may help reduce the itchiness, greasiness, and lesions sometimes associated with dandruff. A 2006 study found that a shampoo with 5 percent tea tree oil (versus a placebo) was used with positive results. A current study found that tea tree oil shampoo produced a 78 percent reduction in microbial growth.

There are a number of ways you can try using tea tree oil to treat dandruff. These include:

  • Purchase a shampoo which includes 5 percent tea tree oil.
  • Add five-to-ten drops of tea tree essential oil to your current shampoo bottle and shake vigorously. Massage into your scalp gently and rinse thoroughly.
  • Make tea tree oil shampoo from scratch. This recipe uses olive oil, vitamin E oil, coconut milk, filtered water, and baking soda, in addition to tea tree oil.
  • According to Poison Control, tea tree oil can be poisonous if swallowed and should not be used in or near the mouth.
  • Make sure to avoid getting tea tree oil into your eyes when you use it on your scalp. If you do get it into your eyes, flush them immediately with warm water, and call your doctor if they become irritated or red.
  • Tea tree oil is not meant to be used at full strength directly on your skin or scalp as it may cause irritation or itching.
  • An Australian study indicated that a small percentage of people are allergic to tea tree oil. Make sure to do a patch test before you use the essential oil, or a product containing tea tree oil, liberally on your scalp. Around 1.4 percent of people who have allergic patch testing done have an allergy to tea tree oil.

Dandruff is not usually serious, although it may mask an underlying condition which has similar symptoms. You should talk to a doctor about your dandruff if:

  • it does not respond to over-the-counter solutions (such as using an anti-dandruff shampoo), or shampooing more often
  • your scalp itches uncontrollably and interferes with daily life or activities
  • your scalp is swollen, red, or contains open sores

Dandruff is a common problem, which is not medically serious. Tea tree oil may be effective at reducing dandruff, particularly if it’s caused by an overabundance of a yeast-like fungus, called malassezia. Tea tree essential oil should never be used at full strength, and should be patch-tested on a small area before using.