Tea tree oil, also known as melaleuca oil, is an
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
with a fresh
camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the k ...
aceous
odor
An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...
and a colour that ranges from pale yellow to nearly colourless and clear.
It is derived from the
leaves
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
of the tea tree, ''
Melaleuca alternifolia'', native to southeast
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, establishe ...
and the northeast coast of
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
,
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
. The oil comprises many constituent chemicals and its composition changes if it is exposed to air and
oxidize
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or ...
s.
Commercial use of tea tree oil began in the 1920s, pioneered by the entrepreneur
Arthur Penfold. the global tea tree oil market was valued at US$39 million.
[
As a ]traditional medicine
Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...
, it is typically used as a topical medication
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
in low concentrations for the treatment of skin conditions, but there is little evidence of efficacy. Tea tree oil is claimed as useful for treating dandruff
Dandruff is a skin condition that mainly affects the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin ...
, acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
, lice
Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a resul ...
, herpes, insect bites, scabies
Scabies (; also sometimes known as the seven-year itch) is a contagious skin infestation by the mite ''Sarcoptes scabiei''. The most common symptoms are severe itchiness and a pimple-like rash. Occasionally, tiny burrows may appear on the ski ...
, and skin fungal or bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
l infections. However, there is not enough evidence to support any of these claims due to the limited amount of research conducted on the topic.[ Tea tree oil is neither a ]patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
ed product nor an approved drug
An approved drug is a medicinal preparation that has been validated for a therapeutic use by a ruling authority of a government. This process is usually specific by country, unless specified otherwise.
Process by country United States
In the ...
in the United States,[ although it is approved as a complementary medicine for aromatherapy in Australia.] It is poison
Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...
ous if consumed by mouth, and unsafe to use on children.[
]
Uses
Tea tree oil has been used as a traditional herbal medicine
Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern remedie ...
in the belief it treats acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
, nail fungus, or athlete's foot
Athlete's foot, known medically as ''tinea pedis'', is a common skin infection of the feet caused by a fungus. Signs and symptoms often include itching, scaling, cracking and redness. In rare cases the skin may blister. Athlete's foot fungus ...
, with little evidence to support these uses.[ A 2015 ]Cochrane Cochrane may refer to:
Places Australia
*Cochrane railway station, Sydney, a railway station on the closed Ropes Creek railway line
Canada
* Cochrane, Alberta
* Cochrane Lake, Alberta
* Cochrane District, Ontario
** Cochrane, Ontario, a town wit ...
systematic review for acne complementary therapies, found a low-quality single trial showed benefit compared to placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures.
In general ...
.
According to the Committee on Herbal Medicinal Products The Committee on Herbal Medicinal Products (HMPC), is the European Medicines Agency's committee responsible for elaborating the agency's opinions on herbal medicines.
Role
HMPC aims at assisting in the harmonization of procedures and provisions con ...
(CHMP) of the European Medicines Agency
The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of medicinal products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products or Eur ...
, traditional usage suggests that tea tree oil is a plausible treatment for "small superficial wounds, insect bites and small boils", that it may help reduce itching in minor cases of athlete's foot, and help with mild inflammation of the mouth lining. The CHMP say tea tree oil products should not be used on people under 12 years of age.
Tea tree oil is not recommended for treating nail fungus as it is not effective. It is not recommended for treating head lice in children because its effectiveness and safety has not been established and it could cause skin irritation or allergic reactions. There is no good evidence tea tree oil is an effective treatment for demodex mite infestations.
Toxicity
Tea tree oil is highly toxic when ingested. It may cause drowsiness, confusion, hallucinations, coma, unsteadiness, weakness, vomiting, diarrhea, nausea, blood cell abnormalities, and severe rashes. It should be kept away from pets and children.[ Tea tree oil should not be used in or around the mouth.]
Application of tea tree oil to the skin can cause an allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derm ...
.[ The potential for causing an allergic reaction increases as the oil ages and its chemical composition changes.] Adverse effects include skin irritation, allergic contact dermatitis, systemic contact dermatitis
Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes are ...
, linear immunoglobulin A disease, erythema multiforme
Erythema multiforme (EM) is a skin condition that appears with red patches evolving into target lesions, typically on both hands.
It is a type of erythema possibly mediated by deposition of immune complexes (mostly IgM-bound complexes) in the ...
-like reactions, and systemic hypersensitivity
Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune ...
reactions. Allergic reactions may be due to the various oxidation products that are formed by exposure of the oil to light and air. Consequently, oxidized tea tree oil should not be used.
In Australia, tea tree oil is one of the many essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
s causing poisoning, mostly of children. In the period 2014-2018, there were 749 reported cases in New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, accounting for 17% of essential oil poisoning incidents.
Hormonal effects
Tea tree oil potentially poses a risk for causing abnormal breast enlargement in men, and pre-pubertal children. A 2018 study by the National Institute of Environmental Health Sciences
The National Institute of Environmental Health Sciences (NIEHS) conducts research into the effects of the environment on human disease, as one of the 27 institutes and centers of the National Institutes of Health (NIH). It is located in the Rese ...
found four of the constituent chemicals ( eucalyptol, 4-terpineol, dipentene
Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels. The - isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring ...
and alpha-terpineol
Terpineol is any of four isomeric monoterpenoids. Terpenoids are terpene that are modified by the addition of a functional group, in this case, an alcohol. Terpineols have been isolated from a variety of sources such as cardamom, cajuput oil, pi ...
) are endocrine disruptor
Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine (or hormonal) systems. These disruptions can cause ...
s, raising concerns of potential environmental health
Environmental health is the branch of public health concerned with all aspects of the natural and built environment affecting human health. In order to effectively control factors that may affect health, the requirements that must be met in ...
impact from the oil.
In animals
In dogs and cats, death or transient signs of toxicity (lasting two to three days), such as lethargy, weakness, incoordination and muscle tremors, have been reported after external application at high doses.
As a test of toxicity
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
by oral intake, the median lethal dose
In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is ...
(LD50) in rats is 1.9–2.4 ml/kg.[
]
Composition and characteristics
Tea tree oil is defined by the International Standard ISO 4730 ("Oil of ''Melaleuca'', terpinen-4-ol type"), containing terpinen-4-ol, γ- terpinene, and α-terpinene as about 70% to 90% of whole oil, while p-cymene, terpinolene, α-terpineol, and α-pinene collectively account for some 15% of the oil (table, right).[ The oil has been described as colorless to pale yellow][ having a fresh, ]camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the k ...
-like smell.
Tea tree oil products contain various phytochemical
Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as poison ...
s among which terpinen-4-ol is the major component.[ Adverse reactions diminish with lower eucalyptol content.][
]
History and extraction
The name ''tea tree'' is used for several plants, mostly from Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
and New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...
, from the family ''Myrtaceae
Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All sp ...
'', related to the myrtle. The use of the name probably originated from Captain James Cook's description of one of these shrubs that he used to make an infusion
Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time (a process often called steeping). An in ...
to drink in place of tea.
The commercial tea tree oil industry originated in the 1920s when Australian chemist Arthur Penfold investigated the business potential of a number of native extracted oils; he reported that tea tree oil had promise, as it exhibited antiseptic
An antiseptic (from Greek ἀντί ''anti'', "against" and σηπτικός ''sēptikos'', "putrefactive") is an antimicrobial substance or compound that is applied to living tissue/skin to reduce the possibility of infection, sepsis, or putre ...
properties.
Tea tree oil was first extracted from '' Melaleuca alternifolia'' in Australia, and this species remains the most important commercially. In the 1970s and 1980s, commercial plantations began to produce large quantities of tea tree oil from ''M. alternifolia''. Many of these plantations are located in New South Wales.[ Since the 1970s and 80s, the industry has expanded to include several other species for their extracted oil: '' Melaleuca armillaris'' and '' Melaleuca styphelioides'' in Tunisia and Egypt; '' Melaleuca leucadendra'' in Egypt, Malaysia and Vietnam; '' Melaleuca acuminata'' in Tunisia; '' Melaleuca ericifolia'' in Egypt; and '']Melaleuca quinquenervia
''Melaleuca quinquenervia'', commonly known as the broad-leaved paperbark, paper bark tea tree, punk tree or niaouli, is a small- to medium-sized tree of the myrtle family, Myrtaceae. It grows as a spreading tree up to tall, with its trunk co ...
'' in the United States. Similar oils can also be produced by water distillation from ''Melaleuca linariifolia
''Melaleuca linariifolia'' is a plant in the myrtle family Myrtaceae, and is endemic to eastern Australia. It is commonly known as snow-in-summer, narrow-leaved paperbark, flax-leaved paperbark and in the language of the Gadigal people as ''budj ...
'' and '' Melaleuca dissitiflora''. Whereas the availability and nonproprietary nature of tea tree oil would make it – if proved effective – particularly well-suited to a disease like scabies that affects poor people disproportionately, those same characteristics diminish corporate interest in its development and validation.[
According to Allied Market Research, "the global tea tree oil market size was valued at $38.8 million in 2017 and is projected to reach $59.5 million by 2025".]
See also
* Cajeput oil
Cajuput oil is a volatile oil obtained by distillation from the leaves of the myrtaceous trees ''Melaleuca leucadendra'', ''Melaleuca cajuputi'', and probably other ''Melaleuca'' species. The trees yielding the oil are found throughout Maritime ...
— derived from ''Melaleuca cajuputi''
References
{{DEFAULTSORT:Tea Tree Oil
Essential oils
Antiseptics
Antifungals
Skin care
Acne treatments
Dermatologic drugs
Traditional medicine
Non-timber forest products
Endocrine disruptors