Manuka Oil

Scientific Name(s): Leptospermum scoparium J.R. Forst. et G. Forst.
Common Name(s): Manuka oil, Red manuka, Tea tree, Teatree

Medically reviewed by Drugs.com. Last updated on Jan 31, 2022.

Clinical Overview

Use

Manuka oil has selective antibacterial activity against Gram-positive organisms particularly S. aureus. Limited studies in wound healing and for anti-inflammatory effect have been conducted.

Dosing

Clinical trials are lacking on which to base dosing guidance.

Contraindications

Avoid use during pregnancy because of reported spasmolytic activity.

Pregnancy/Lactation

Documented adverse effects. Avoid use during pregnancy because of reported spasmolytic activity.

Interactions

None well documented.

Adverse Reactions

L. scoparium contains a lipophilic flavonoid that specifically interacts with benzodiazepine receptors (GABA-A receptor-chloride channel complex).

Toxicology

There are limited clinical toxicological data on manuka oil in the scientific literature.

Scientific Family

• Myrtaceae (Myrtle)

Botany

L. scoparium is the only Leptospermum species native to New Zealand. Its size ranges from a creeping plant to a small tree (of 8 m in height) and it is widely distributed in various climatic and altitudinal zones in New Zealand. The physical characteristics, such as flower and leaf color, leaf size and shape, branching habit, and foliage density vary considerably among populations. Manuka oil should not be confused with Melaleuca alternifolia (see Tea Tree Oil monograph).Melching 1997, Porter 2001, Porter 1999, USDA 2017

History

Early New Zealand records indicate that the plant's bark, leaves, sap, and seed capsules were used in beverages and medicinal preparations.Porter 1999 The plant was valued for its medicinal properties and wood by the indigenous Maori people; the wood was utilized for gardening tools, fishing, housing structures, and weapons.Porter 2001, Riley 1994

Captain James Cook used the leaves of the plant as a tea to combat scurvy during long explorations of the southern hemisphere; early European settlers of New Zealand adopted Captain Cook's use of the plant as a tea.Porter 2001

Commercial development of the essential oils has led to a range of OTC products marketed in New Zealand and exported to European and Asian markets. These products are used for topical treatment of various conditions including the following: Fungal and bacterial skin infections; inflammation from sunburn, insect bites, or joint pain; eczema or psoriasis. The oils also are used in perfumes and soaps.Porter 2001

Chemistry

The L. scoparium populations of New Zealand are highly variable in oil chemical composition and activity.Perry 1997, Priest 2002 Standardized steam distillation and gas chromatography-mass spectrometry of the essential oils of 15 New Zealand L. scoparium populations identified the following in various quantities per species: alpha-pinene, beta-pinene, myrcene, rho-cymene, 1,8-cineole, linalol, methylcinnamate, alpha-farnesine, isoleptospermone, leptospermone, sesquiterpenes such as cadina-3,5-diene and delta-amorphene, and triketones.Melching 1997, Porter 1999, Perry 1997

Triterpenoids and flavonoids (including methylated and methoxylated flavonoids such as 5,7-dimethoxyflavone, 5-hydroxy-7-methoxy-6-me...