Tea tree oil can be good for your hair, but it has some limits. Tea tree oil is an essential oil that comes from the leaves of the Australian Melaleuca alternifolia tree. It’s known for its strong antimicrobial and anti-inflammatory properties, which help it reduce flakes, fight scalp irritation, and promote hair growth.

That said, tea tree oil is not a miracle cure, and it can also lead to irritation in some cases.

Researchers have studied many potential effects of tea tree oil use, including those that may benefit your hair’s growth, health, and appearance.

Tea tree oil helps control oil production on your scalp, which may reduce how greasy or dirty your hair gets and lead to more clean, healthy shine.

By keeping your scalp clean and free of buildup, tea tree oil creates a healthier environment for your hair follicles. Healthier follicles may improve your hair’s growth.

Diluting tea tree oil with a nourishing carrier oil, like argan oil or jojoba oil, can help lock in moisture and relieve tight, flaky skin. Tea tree oil’s anti-inflammatory effects may also help calm irritation, redness, and itching caused by dryness, dandruff, or eczema on your scalp.

Tea tree oil shampoos are commonly marketed for flake control, thanks to antifungal activity against the yeast that fuels dandruff. A meta-analysis found tea tree oil targets Malassezia, the yeast linked to dandruff. By stopping this fungal growth, tea tree oil may reduce flaking.

Some studies show tea tree oil, especially when combined with other natural oils, can reduce lice infestations.

Tea tree oil is potent, so always dilute it. Here are safe ways to use it:

• Mix with a carrier oil: Add two to three drops of tea tree oil to a tablespoon of argan, jojoba, or olive oil. Massage the mixture into your scalp and rinse after 15–20 minutes.
• Add to shampoo or conditioner: A few drops of tea tree oil in the bottle can boost your regular products.
• Choose ready-made products: Shampoos and treatments made with tea tree oil as an ingredient may be safer, as they use controlled amounts.
• Test for a sensitivity reaction: Always test a small amount of the diluted tea tree oil on a small area of your skin to check for sensitivity before you apply it fully to your hair or scalp.

Tea tree oil is natural, but that doesn’t mean it’s risk-free. Keep these points in mind before using it:

• Never ingest it: Tea tree oil is toxic if swallowed and can cause confusion, drowsiness, or other serious symptoms. It should only ever be used topically (on the skin and hair).
• Patch test first: Even diluted, tea tree oil can trigger an allergic reaction in some people. Apply a small amount to your inner arm and wait 24 hours to see if irritation develops.
• Children and pregnancy: Because of limited safety data, avoid using tea tree oil in young children, and talk to a doctor before using it while pregnant or breastfeeding.
• Underlying scalp conditions: If you have psoriasis, severe eczema, or stubborn dandruff that doesn’t improve, see a dermatologist. Tea tree oil may help with mild skin symptoms, but more severe cases may require medical care instead of natural remedies.
• Frequency of use: A little goes a long way. Overuse of tea tree oil can cause dryness or irritation, so start by using it once a week and adjust based on how your scalp responds.