For years, tea tree oil has been an incredibly popular ingredient in many high-end shampoos and in medicinal treatments for dandruff and other scalp conditions such as seborrheic psoriasis.
Recently, a good bit of noise has been made claiming tea tree oil to be an effective treatment for hair loss and help with hair growth.
This article intends to sift through the noise so that consumers can make an informed decision as to whether these claims have any merit.
We will get there by answering the following questions:
- What is tea tree oil?
- What are its hair-related benefits?
- What does the science say?
- What are the side effects?
- How is it used?
What is Tea Tree Oil?
Tea tree oil is an essential oil extracted from the leaves of a native Australian shrub known as Melaleuca alternifolia. It is known for its strong, minty smell and its many uses as an effective home remedy due to its proven antimicrobial and antiseptic properties (1).
It is believed that tea tree oil’s medicinal benefits are due to its natural chemical compounds — specifically eucalyptol, cineole, viridiflorol, nerolidol, and terpinen-4-o.
Here is an interesting bit of history: The tea tree was given its name by Captain James Cook in 1770. Shortly after landing in Botany Bay, Australia, Captain Cook discovered that the leaves from the Melaleuca alternifolia made a delicious, minty tea.
He brought it back to Europe, where it became a bit of a sensation and remains popular to this day. Granted, this information has no relevance to our discussion here, but it is interesting nonetheless.
What Are Its Hair-Related Benefits?
Tea tree oil has proven natural antifungal and antibacterial properties that help in maintaining a clean, healthy scalp and strong, healthy hair follicles. The benefits of tea tree oil in this regard are as follows:
- Tea tree oil moisturizes hair to help soothe dry and itchy scalp, the root cause of dandruff.
- Tea tree oil fights bacterial, fungal, and other infections to keep the scalp healthy (3, 4).
- Tea tree oil prevents the build-up of dead skin cells and residue of commercial hair products.
- Tea tree oil controls excess hair oils.
All of the above suggests that tea tree oil could have a direct benefit in treating hair loss if the cause is related to clogged hair follicles, dead skin buildup, or some sort of scalp condition.
With regards to new hair growth, tea tree oil could have an indirect benefit to the degree that a healthy scalp supports healthy hair growth.
Tea tree oil has also been said to have antiandrogenic properties that could help with counteracting androgenic baldness most frequently occurring in males (5).
The justification goes like this:
Anti-androgens are medications taken by women to counter the effects of male sex hormones. Male hormones lead to baldness. Thus, antiandrogenic properties in tea tree oil may help contain the problem of hair loss.
There is no scientific evidence to support the claim that tea tree oil has any relationship to or impact on androgenetic baldness.
To date, there have been no suggestions or claims that tea tree oil could be used to treat hair loss associated with autoimmune conditions, heredity, or age.
What Does the Science Say About Tea-Tree Oil?
Here is another interesting bit of history. The Australian Aborigines used tea tree oil as a remedy for snake bites. For this reason, it was sometimes referred to as Snake Oil. When the US settlers arrived in America, “snake oil” (actually tea tree oil) was suddenly in popular demand.
Unfortunately, many of the salesmen selling what they referred to as snake oil were not tea tree oil at all and it did not work. This is where the pejorative term Snake Oil Salesman came from.
So what does the science say? Is tea tree oil “snake oil”?
The above claims linking tea tree oil to hair loss treatment are related to three supposed properties of the essential oil: antimicrobial, antifungal, and antiandrogenic. The science behind each of these is presented as follows.
Tea Tree Oil is an Antimicrobial
Scientific evidence to support the antimicrobial properties of tree oil is overwhelmingly strong. To date, over 327 scientific studies refer to the oil’s antimicrobial prowess alone. An excellent presentation of the research that has been done in this regard can be found in the journal Clinical Microbiology Reviews (7).
It is excellent reading material for any who may be interested in a survey of the research done to date.
Tea Tree Oil is Antifungal
For years, evidence to support tea tree oil’s antifungal properties was strictly anecdotal. The first major clinical study in this regard was published in the Australasian Journal of Dermatology in 1992 (8).
This research trial was one of the first to show that tea tree oil appears to reduce the symptoms of athlete’s foot as effectively as tolnaftate 1%, the most typically prescribed treatment for the condition.
More recent, smaller-scale clinical studies have suggested that tea tree oil is an effective treatment for various fungal infections that can cause hair loss, including yeast, ringworm, athlete’s foot, and other infections of the skin, hair, and nails.
Tea Tree Oil is Antiandrogenic
To date, there have been two primary studies suggesting that there may be antiandrogenic properties in tea tree oil. Most, if not all, of the claims of tree oil’s efficacy in treating androgenic baldness, cite these two studies as evidence. Both of these studies are presented below.
The first study was published in 2007 in the New England Journal of Medicine.
In that study, a group of pediatric and molecular endocrinology researchers at the National Institute for Environmental Health Sciences (NIEHS) showed that the topical application of lavender and tea tree oil-containing products may be linked to gynecomastia (breast growth) in three pre-pubescent boys.
They reached this conclusion by using cell culture-based assays to demonstrate that very low concentrations of both lavender and tea tree oils are weak stimulators of a biological process that increases three well-known estrogen-responsive genes.
They also concluded that the oils had antiandrogenic activity, substantially repressing the activity of four genes usually stimulated by the primary circulating androgen, dihydrotestosterone (DHT).
In other words, they found that topical application of lavender and tree oils seems to produce a combination of pro-estrogenic and antiandrogenic effects to cause the development of breast tissue in these boys.
The second study was published in the Journal of Endocrinological Investigation in 2013 (10). In this study, researchers investigated the effectiveness of lavender and tea tree oils in the treatment of a condition known as idiopathic hirsutism, or excessive bodily or facial hair growth in women.
What these researchers found was that lavender and tea tree oils applied locally on the skin could be effective in reducing mild idiopathic hirsutism, suggesting that these oils may have antiandrogenic properties.
In short, the scientific evidence supporting tea tree oil’s antiandrogenic properties is scant at this point. Also, there has been no research tying the antiandrogenic properties of tea tree oil to treating androgenetic baldness.
What Are the Side Effects?
Like any other essential oil, tea tree oil is highly concentrated and poses safety risks when used improperly or in the wrong concentrations. When used topically, it should always be diluted with a carrier oil, such as coconut oil or olive oil. I recommend 5mL of carrier oil for each drop of essential oil.
Following are the most significant side effects and cautions associated with tea tree oil.
- Too much of it, when topically applied, can be irritating to the scalp and cause an adverse reaction.
- When applied near the ears, eyes, and mouth, irritation is possible. As such, avoid contact with these sensitive areas.
- Tea tree oil is harmful if swallowed, so do not ingest it under any circumstances.
- An allergic reaction to tea tree oil is possible. For this reason, it is wise to do a small skin patch test first to ensure there is no adverse reaction before using larger amounts.
How is it Used?
There are several ways to use tea tree oil and apply it to the hair and scalp. All of them produce a tingling feeling that is perfectly normal.
The simplest way is to take a few drops in the palm of your hand, spread it across both hands and massage it into the scalp thoroughly. This procedure can be done weekly.
Warm Oil Treatment
A warm oil treatment is prepared by mixing tea tree oil with carrier oil at a ratio of 5mL of carrier oil for each drop. The oil is heated and then rubbed into the scalp.
The hair is then wrapped in a warm towel. After twenty minutes, the oil can be gently rinsed from the hair. This procedure can be done safely 3 to 4 times a month.
Shampoo and Conditioner
There are numerous tea tree shampoos and conditioners on the market. Almost all are expensive. For a cheaper alternative, it can be done by mixing a drop or two of the oil into the shampoo or conditioner in your hand.
After the shampoo and oil are massaged into the hair, it is then left to sit for a couple of minutes before rinsing.
There is significant evidence to support the efficacy of tea tree oil as an effective hair and scalp treatment due to its proven antimicrobial and antifungal properties.
There is also reason to believe that some types of hair loss—specifically, those associated with scalp and hair follicle conditions—could be treated by tea tree oil.
It is also reasonable to suppose that tea tree oil could aid indirectly in the stimulation of new hair growth, depending on the cause of the hair loss.
However, there is no credible scientific evidence that suggests tea tree oil is an effective treatment for hair loss caused by illness, medications or genetics.