School of Pathology and Laboratory Medicine

Frequently Asked Questions

This page addresses some common questions about tea tree oil.

The information provided on this website is not, and must not be taken as, medical advice. If you require medical advice you should always consult your doctor. Please contact a member of the research group if you have a query that is not covered here.

What does the name "tea tree" refer to?

What other names does tea tree oil have?

Where can I find out more about tea tree oil?

How many components are in tea tree oil?

Does tea tree oil have different grades?

What is the best way to apply tea tree oil?

Can topically applied tea tree oil cure cancer?

Can I use topical tea tree oil instead of antibiotics?

Can bacteria become resistant to tea tree oil?

What evidence is there that tea tree oil really works?

 

Safety

Is tea tree oil completely safe because it is natural?

Can tea tree oil be swallowed?

Is tea tree oil safe to use whilst pregnant or breastfeeding?

Isn't tea tree oil a skin irritant? Will I become allergic to it?

Tea tree is a common name that has been applied to several different plants, including those in the Melaleuca and Leptospermum genera. Oils from only a few of these plants can be called tea tree oil and most tea tree oil is produced from Melaleuca alternifolia.

Ti-tree is another common name used for Leptospermum and also Cordyline plants. 

What other names does tea tree oil have?

Tea tree oil is also called melaleuca oil. It is not the same as;

  • Chinese tea oil, which is derived from the seeds of Camellia oleifera.
  • New Zealand tea tree oils, which are derived from Kunzea ericoides and Leptospermum scoparium and are also known as kanuka and manuka oils respectively.

Where can I find out more about tea tree oil?

We have published several reviews on tea tree oil and our publications contain more details of our research. In addition, there are several excellent websites that give more information about tea tree oil.

To search for all scientific publications on tea tree oil you can go to PubMed or Google Scholar and type in the search term "tea tree oil".

Tea tree oil contains over 100 components, most of which have been identified. The major component in the monoterpene terpinen-4-ol, which typically comprises 40% of the whole oil.

Does tea tree oil have different grades?

Some companies market TTO as “medicinal”, "pharmaceutical" or “premium” grade. This is usually based on these oils containing a slightly higher percentage of terpinen-4-ol. However, there is no scientific evidence that these oils are more antimicrobially active than regular TTO.

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Tea tree oil must only be applied topically and should not be swallowed. Tea tree oil can cause irritant reactions so it is better to apply it to the skin in a gel, cream or lotion instead of undiluted. A range of products is available from supermarkets, pharmacies or health food stores that are suitable for topical use.

In addition to this general information, how you apply the tea tree oil product may need to be tailored to the condition that you are intending to treat. It may also be advisable to apply a small amount of product to your inner arm first to see if a reaction occurs. 

Can topically applied tea tree oil cure cancer?

No. Our studies to date have shown that topically applied tea tree oil formulations can inhibit the growth of subcutaneous tumours in mice. We still need to test the tea tree oil formulations in a controlled clinical trial in human patients with skin cancers or precancerous lesions. Although there is some anecdotal evidence to suggest that topical tea tree oil may have an effect against skin cancers in humans, we do not recommend anyone self treat their skin cancers or precancerous lesions with any untested product and that people see their GP or dermatologist for diagnosis/treatment.

Topical tea tree oil can not replace antibiotics. The antimicrobial properties of tea tree oil mean that is suitable for the treatment of some superficial skin infections. Oral antibiotics are prescribed to treat serious infections systemically. Since tea tree oil can not be taken orally it cannot be used the same way as oral antibiotics.

Can bacteria become resistant to tea tree oil?

Recent scientific studies by our research group show that it is extremely unlikely that resistance to tea tree oil can arise. This is supported by research from other groups around the world.

What evidence is there that tea tree oil really works?

The antimicrobial activity of tea tree oil has been shown in many different laboratory studies. These provide the foundation for clinical studies where tea tree oil products are evaluated using volunteers. 

Clinical studies have shown that tea tree oil is effective for treating several superficial infections or conditions where bacteria or fungi are involved. These include acne, cold sores, tinea, fungal nail infections, dandruff and oral candidiasis. These studies generally showed that treatment with tea tree oil was either the same as standard treatment or better than no treatment or placebo.    

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Is tea tree oil completely safe because it's natural?

It is a common misconception that because a product is natural it is also safe. There are many examples of natural substances, such as lead, arsenic and asbestos, that are very harmful. Tea tree oil is poisonous if swallowed and should only be used topically.

No. Tea tree oil can be toxic if ingested in large enough quantities. It should only be applied topically. The small amounts of tea tree oil contained in oral hygiene products such as toothpastes and mouthwashes is not considered problematic since it is expelled from the mouth and not swallowed.

Special consideration needs to be given to the use of tea tree oil during pregnancy and breastfeeding. There are no data showing that the use of tea tree oil during pregnancy or breastfeeding is either safe nor unsafe.

Since we cannot conclusively state whether it is safe or not a conservative approach is taken and it is therefore generally not recommended. This is the same approach used with other medicines.

Isn't tea tree oil a skin irritant? Will I become allergic to it?

Tea tree oil can be irritating to skin. However, not everyone reacts the same and there is quite a bit of variability from person to person. Irritancy is also concentration-dependent, meaning that higher concentrations of tea tree oil are more irritating than lower concentrations.

Whether or not tea tree oil will irritate your skin depends on your own skin type and the concentration of tea tree oil that you apply.

Allergy to tea tree oil (or any substance) required repeated applications to develop whereas an irritant reaction can happen on the first application. A small proportion of the population has an allergy to tea tree oil and will generally react even when the concentration of tea tree oil is reduced.