A fresh look at manuka and kanuka essential
oils from New Zealand
*, J.M. Wilkinson
, D. Shillington
Universal College of Learning (UCOL), Private Bag 11022, Palmerston North, New Zealand
School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, Australia
Summary Essential oil is obtained from manuka, Leptospermum scoparium and
kanuka, Kunzea ericoides, which are indigenous plants to New Zealand. The oil
from these plants has been commercially available to aromatherapists for more
than a decade. In this time, attention has been given to the antiseptic and anti-
microbial actions of the oils. Of most interest to researchers and aromatherapists
is the presence of b-triketones, present in the manuka oil. These triketones are
believed to signiﬁcantly contribute to the antimicrobial action. More recently, it
has emerged that there are signiﬁcant geographical variations affecting the com-
position of these oils. Whilst a full understanding of the therapeutic implications
is some way off, it is important for aromatherapists to appreciate that these
differences exist and the oils selected may match the intended therapeutic
c2005 Elsevier Ltd. All rights reserved.
In recent years, there has been considerable
interest in the therapeutic potential of two
commercially produced essential oils from New
Zealand. These are: manuka, Leptospermum
scoparium J. R et G. Forst and kanuka, Kunzea
ericoides (A. Rich Thompson, formerly called
Leptospermum ericoides). Manuka is also known
as kahikatoa, red manuka and tea tree. Kanuka
is also known as white or tree manuka as it is
larger than the manuka with smaller leaves,
ﬂowers and fruit with a white wood (Booker
et al., 1987). Of the 79 Leptospermum species,
manuka is the only one that is native to New
Zealand; however, some controversy exists as to
whether both manuka and kanuka are also
endemic to Australia (Perry et al., 1997). Both
0962-4562/$ - see front matter
c2005 Elsevier Ltd. All rights reserved.
*Corresponding author. Tel.: +64 6 9527000x70821.
E-mail address: email@example.com (W. Mad-
The International Journal of Aromatherapy (2005) 15, 141–146
manuka and kanuka grow proliﬁcally through both
islands of New Zealand. Maori lore attributes the
kanuka as being the ‘male’ tree and the manuka
the ‘female’ (Booker et al., 1987). Aromathera-
pists and other practitioners need to understand
that there are variations in composition, espe-
cially of manuka oil, which can inﬂuence clinical
selection. This discussion will outline the
differences and propose some potential therapeu-
As with the Australian tea tree Melaleuca alterni-
folia, the common name relates to the uses that
Captain Cook had for the dried leaves when he
was exploring New Zealand in the eighteenth cen-
tury. History records a diverse range of uses by
both indigenous Maori and early European settlers.
These include infusions for ‘immoral people’, uri-
nary and intestinal complaints, as a febrifuge,
sucking the gum for coughs, vapour inhalations
for colds, poultices for back pain and skin condi-
tions, inﬂamed breasts, burns and scalds, mouth-
washes and gargles, gum disease. The wood was
also used for canoe structures, ﬁshing tools, gar-
dening tools, war weapons and ﬁrewood. The gum
or manna has mannitol as a main ingredient, which
was used medicinally to relieve oedema and re-
move excess ﬂuid from the body (Booker et al.,
Habitat and production
New Zealand lies in the Southern Hemisphere in the
Paciﬁc Ocean. Its nearest landmass is Australia,
which lies to the west. New Zealand has two main
islands, the North and the South. Whilst the cli-
mate may be considered temperate there are wide
variations from the subtropical Northland rainfor-
ests to the glacial and alpine Deep South. Rainfall
varies with the western side of both islands receiv-
ing higher rainfall. Annual rainfall is between 600
and 1600 mm per year. Annual temperature aver-
ages from 10 °C in the South and 16 °Cinthe
North, with July being the coldest month
overview>). The areas where manuka oil is har-
vested for distillation range in latitude from
35°240in Auckland, in the North Island, to 45°530
in Otago in the South Island. Essential oil yield
ranges from 0.17% to 0.57% depending on the loca-
tion grown (Perry et al., 1997).
As both plants grow readily most commercial
production is from wild harvested areas rather than
plantation type locations, with the distilled oil
being incorporated into a variety of commercially
prepared products as well as being sold undiluted.
Re-growth is rapid after harvesting therefore there
is currently no risks of damage to a wild resource.
In the future, however, plantations may evolve
specialising in a particular chemotype, in a similar
fashion to Australian tea tree with high terpinen-
4-ol content. Essential oil is obtained from manuka
and kanuka through steam distillation of the leaves
and branches. However, manuka may require a
lengthy distillation period (up to 5 h) to ensure that
the maximum amount of b-triketones is present
(Porter, 2001). Of the two, manuka is more popular
and hence most of the existing literature relates to
Manuka and kanuka have around 100 different con-
stituents present; however, not all have been iden-
tiﬁed with certainty. Almost all of the volume
(95%) is attributed to about 50% of the constituents
(Christoph et al., 1998). It is of value to aromather-
apists and other health professionals to understand
that these two oils are quite unique particularly
when compared to their close relatives from the
Myrtaceae family. Table 1 compares the main con-
stituents of common essential oils of the Myrtaceae
family commonly used within aromatherapy
Manuka oil distilled from plants grown in the
North Island, especially around the East Coast area
have higher (>30%) levels of triketones (leptosper-
mone and ﬂavesone), where as South Island oils
contain more sesquiterpene hydrocarbons and oxy-
genated hydrocarbons (up to 65%). Total monoter-
pene content also varies from 3% to 40% depending
on the location grown (Perry et al., 1997). Essential
oil distilled from L. scoparium grown in Australia
has much lower levels of both triketones and ses-
quiterpenes (Flynn et al., 1979; Perry et al.,
1997). Variances in composition have also been
noted depending on the age of the plant. For exam-
ple, the amount of monoterpenes (a-pinene,
b-pinene and myrcene) increases from less than
1% in young trees to between 17% and 34% from
trees that are three years older. These variations
are also seasonal, with pinene levels at their highest
in the spring and summer when the foliage is grow-
ing. These factors are all important when consider-
ing commercial production (Porter et al., 1998).
142 W. Maddocks-Jennings et al.
Table 1 Comparison of various essential oils from the Myrtaceae family
K. ericoides S.I
K. ambigua Australia
a-Pinene 0 0 0 1.30 6.3 61.6 72.4 39.9
b-Pinene 0.90 0 20 0.50 0.4 0 0.7 0
Myrcene 0 0 0 0 1.7 – 0.3 0
p-Cymene 0 0 0 0 0.7 2–5 2.9 0
11.80 0.40 Trace 33 2.4 <3 <8
Sesquiterpenes Trace Trace Trace 10.5–34 70 <2 7 5
<50 >60 0 <7 6 5.1 15.8
Globulol Trace 0 >14 0 0 0 0 11.9
600 0000 0
Viridiﬂorol 0 0 3.20 Trace 0 3.2 ? 9.4
Geraniol 0 0 0 0 7.2 0 0 0
Linalool 0 0 0 ?Trace 6–20 0 1.4 0
a-Terpineol 0–Trace 20 5.70 ? 0–1.3 1.1 0 2.9
Caryophyllene 0 0 0 <3 8.3 0 0 ?
Humulene 0 0 0 ?Trace 5.5 0 0 ?
Eudesamol isomers 0 0 00 0 10.11 0 0 ?
Leptospermone 0 0 0 10–20 0 0 0 ?
Iso-leptospermone 0 0 0 2–7 0 0 0
Calamenene 0 0 0 >9 1.5 0 1.1 0
Sheppard-Hanger (1998);Webb (2000).
Chemical analysis of South Island Manuka and Kanuka supplied by Brooklyn Valley Essential oils with permission (results from two different harvests).
Kunzea analysis, Webb (2000, 2002).
The Australian Standard (AS 2782-1985) states that 1.8 cineole must be <15% and the terpinene-4-ol content >30% (Carson et al., 1995).
A fresh look at manuka and kanuka essential oils from New Zealand 143
Initially, four chemotypes were identiﬁed based
on the amounts of leptospermone present (Porter
and Wilkins, 1999). Leptospermone has the full
chemical name of 3,5-hydroxy-4-(2-methyl-1-
1,3-dione (van Klink et al., 1999). Group I is rich in
triketones and occurs primarily in the East Coast of
the North Island of New Zealand. Group II is high in
linalool and eudesamol, and mainly occurs in the
Nelson region, northern South Island. Group III is
rich in pinenes from Canterbury in the Central
South island. The fourth group is deﬁcient of all
the above constituents in any signiﬁcant level and
are found scattered around the country. The den-
sity and refractive index of a sample helps deter-
mine the potential antibacterial activity without
the need for expensive GLC analysis of each batch.
When the polar fraction, which contains the trike-
tones, is removed from a sample the remaining
non-polar sample is inactive against bacteria (Por-
ter and Wilkins, 1999). More recent research has
identiﬁed a further 10 chemotypes with varying
amounts of terpenes, sesquiterpenes, linalool and
esters amongst other constituents (Douglas et al.,
2004). Despite the obvious differences in constitu-
tion, the geographical location is rarely noted on
price lists unless purchasing directly from a grower
(see Fig. 1).
The sesquiterpene hydrocarbon, ()-trans-
), is present between 9.6%
and 18% in some manuka oils, mainly from the
South Island. Guenther (1975) makes a brief men-
tion that calamenene is formed from calamenol
when it loses its water. As a group, sesquiterpene
hydrocarbons are less common than the monoter-
penes (Tisserand and Balacs, 1995) and they are
believed to be antiseptic, bactericidal, analgesic
and antiinﬂammatory (Sheppard-Hanger, 1998).
Calamenene is also found in calamus, clove bud,
Tolu balsam and black pepper (Sheppard-Hanger,
1998). There does not appear to be any correlation
between the amount of leptospermone and ()
-trans-calamenene present; therefore its presence
can only be detected by GLC analysis. Total sesqui-
terpene hydrocarbon content can range between
60% and 70% consisting of at least 30 different ses-
quiterpene hydrocarbons (Christoph et al., 1998).
Within South Island manuka there is also humulene,
selinene and cadinene which may not be famil-
iar constituents to aromatherapists. South Island
kanuka has spathulenol, which does not appear to
be present in other samples.
Much of the current empirical literature evaluates
the antimicrobial effects of manuka and kanuka
(Rhee et al., 1997) and comparing these effects
with the more common M. alternifolia. Earlier
studies indicate that manuka is effective against
Gram-positive organisms and ringworm and kanuka
has some action against these as well, but neither
are as effective as tea tree (M. alternifolia) against
Gram-positive organisms (Cooke and Cooke, 1991;
Lis-Balchin, 1996; Lis-Balchin et al., 1996a,b; Lis-
Balchin and Hart, 1998). With manuka, the antimi-
crobial actions are attributed to the b-triketones,
namely leptospermone, isoleptospermone and
ﬂavesone (Christoph et al., 2000). Various investi-
gations of the effects of manuka, kanuka, cajeput
(Melaleuca cajeputi), niaouli (Melaleuca quinquen-
ervia) and a b-triketone complex (containing ﬂave-
sone, isoleptospermone and leptospermone) on
several microorganisms were conducted by Chris-
toph et al. (2000).a-Terpineol was used as a posi-
tive control. Each oil was tested against both
Gram-negative and Gram-positive bacteria, a
yeast, dermatophytes and moulds using minimal
inhibitory concentrations (MIC) to determine
M. alternifolia had the broadest range of ef-
fects, followed closely by M. cajeputi and M. quin-
quenervia, which are both high in 1,8-cineole.
Kanuka was only effective against Gram-positive
bacteria at concentrations of between 0.2% and
0.4%; this was lower than tea tree at 0.2–0.45%.
Kanuka had virtually no effect against the yeasts.
Figure 1 Map of New Zealand.
144 W. Maddocks-Jennings et al.
Manuka had mixed effects on all microorganisms,
with greater potency against the Gram-negative
organisms at concentrations of 0.05–0.15%. It
was the most effective of all the whole oils against
P. aeruginosa at 0.85% compared to 1–2% for the
rest of the whole oils. Manuka had virtually no
effect against the moulds and yeast, but was most
effective against the dermatophytes, at 0.3%
compared to 0.6–1.1% for the rest. Most notably
the b-triketone complex was the most effective
against all the microorganisms, except for moulds.
It was higher than the complete manuka oil, from
which it originated. The authors suggest that this
effect may be due to the different lipophilicity
(fat solubility) of the whole oil as it contains up
to 70% of terpene hydrocarbons, which are lipo-
philic. The lack of effect of kanuka oil on C. albi-
cans may also be due to the high percentage of
terpene hydrocarbons (85%), whereas the other
oils, which are effective, contain lower amounts
and also sesquiterpene hydrocarbons (Christoph
et al., 2000).
A later study then explored the effects of adding
the b-triketone complexes to both M. alternifolia
and M. quinquenervia (Christoph et al., 2001). In
this study there was a 40% increase in inhibition
of S. aureus and M. catarrhis (a respiratory patho-
gen) but not with P. aeruginosa or E. coli, with var-
iable activity noted. Manuka also had some activity
against skin and ringworm fungi. Studies conducted
on North and South Island manuka and kanuka and
other New Zealand grown plants indicate that
North and South Island manuka is spasmolytic on
smooth muscle from the guinea pig and North and
South Island kanuka was found to be spasmogenic
(Lis-Balchin et al., 1996a,b). This was attributed
to the high a-pinene content of the kanuka oils.
In comparison, M. alternifolia and L. petersonii
(lemon tea tree) were spasmolytic. Both manuka
and kanuka oils had variable antibacterial and anti-
fungal activity, much lower than tea tree and the
oils of thyme, origanum and marjoram. L. peterso-
nii also had variable antibacterial and antifungal
activity but overall performed better than manuka
or kanuka. A combination of North Island manuka
and kanuka had higher activity than the individual
oils. Lis-Balchin et al. (1996a,b) concluded that
manuka and kanuka should not be considered as
being useful as universal antibiotic oils, especially
as they are more expensive than the other oils
internationally, which are more effective and more
readily available. Within New Zealand manuka is
comparable to Australian tea tree in price.
However, there does appear to be value in using
manuka oil as an antispasmodic (Lis-Balchin and
In vitro studies suggest that kanuka oil is effec-
tive against Herpes simplex Type 1 and Polio Type
1 viruses. The active compounds were identiﬁed
as isomers of isobutyryl methoxyresorcinol and un-
named b-triketones (Bloor, 1992). Larger clinical
trials relating to this have not been located.
Clinical implications for aromatherapists
Both manuka and kanuka essential oils have a ther-
apeutic potential beyond the antimicrobial actions
noted above. There does not appear to be any tox-
icology concerns relate to either oil based on the
identiﬁable constituents present. A search through
the literature did not reveal any published reac-
tions to either oil. Lis-Balchin et al. (2000) believes
that caution should be applied with these oils as
there has not been formal toxicology studies con-
ducted. They also conducted a series of studies
on various animal tissues and note that manuka
and kanuka decrease the force of spontaneous con-
tractions of the uterine muscle cells which may be
of concern in pregnancy and labour (Lis-Balchin
et al., 2000). Anecdotal information gathered
informally from aromatherapy students and practi-
tioners in New Zealand suggest that these oils have
been used extensively without undue concern. One
aromatherapist reported that kanuka was used in a
bath for a lady who was pregnant and her skin
reacted, whereas she had used the oil extensively
without problem prior to being pregnant. It would
be valuable to know if there are any other
examples of possible reactions attributed to either
kanuka or manuka.
Given the presence of several sesquiterpene
hydrocarbons there is considerable scope to utilise
the oils for their anti-inﬂammatory and antispas-
modic actions. Kanuka oil from the North and South
Island has p-cymene present, which suggests it has
analgesic properties (Sheppard-Hanger, 1998).
Possible conditions include chronic inﬂammatory
conditions such as polymyalgia rheumatica, ﬁbro-
myalgia, and rheumatoid arthritis. Possibly kanuka
would be of beneﬁt in incidences of acute muscle
strain acting as an analgesic and anti-inﬂamma-
tory. As aromatherapists are used to purchasing
different chemotypes of some oils such as rosemary
and thyme species, it would be prudent to consider
this with manuka and kanuka. At the very least a
practitioner should know which island in New Zea-
land the oil has been produced from and ideally
some indication of sesquiterpene and b-triketone
content. From an aesthetic perspective both man-
uka and kanuka have distinctive aromas, which
some may ﬁnd appealing. Both oils would blend
A fresh look at manuka and kanuka essential oils from New Zealand 145
well with wood oils such as sandalwood or cedar-
wood. The aroma can be softened with the addition
of lavender, lemon or lemon myrtle (Backhousia
citriodora). However, it does depend what action
the individual aromatherapist is aiming to achieve
from the blend as to what oils are chosen.
Bloor SJ. Antiviral phloroglucinols from New Zealand Kunzea
species. J Nat Prod 1992;55(1):43–7.
Booker SG, Cambie RC, Cooper RC. New Zealand medicinal
plants. Auckland: Reed Books; 1987.
Brooklyn Valley essential oils, analyses of manuka and kanuka oil
samples, supplied by the distillers with permission. Available
Carson CF, Cookson BD, Farrelly HD, Riley TV. Susceptibility of
methicillin-resistant Staphylococcus aureus to the essential
oil of Melaleuca alternifolia. J Antimicrob Chem
Christoph F, Kaulfers PM, Stahl-Biskup E. A comparative study of
the in vitro antimicrobial activity of tea tree oils s.l. with
special reference to the activity of beta-triketones. Planta
Christoph F, Kaulfers PM, Stahl-Biskup E. In vitro evaluation of
the antibacterial activity of b-triketones admixed to melal-
euca oils. Planta Med. 2001;67(8):768–71.
Christoph F, Kubeczka K-H, Stahl-Biskup E. The composition of
commercial manuka oils from New Zealand. J Essent Oil Res
Cooke A, Cooke MD. An investigation into the antimicrobial
properties of manuka and kanuka oil. Cawthron Institute
Douglas MH, van Klink JW, Smallﬁeld BM, Perry NB, Anderson RE,
Johnstone P, Weavers RT. Essential oils from New Zealand
manuka: triketone and other chemotypes of Leptospermum
scoparium. Phytochemistry 2004;65(9):1255–64.
Flynn TM, Lassak EV, Smyth MP. The volatile leaf oils of three
species of Leptospermum. Phytochemistry 1979;18:2030–1.
Guenther E. The essential oils, vol. II. Florida: Kriegar Publish-
ing Company; 1975.
Lis-Balchin M, Hart SL. An investigation of the actions of the
essential oils of manuka (Leptospermum scoparium) and
kanuka (Kunzea ericoides), Myrtaceae on guinea pig smooth
muscle. J Pharm Pharmacol 1998;50(7):809–11.
Lis-Balchin M, Hart S, Deans SG, Eaglesham E. Comparison of the
pharmacological and antimicrobial action of commercial
plant essential oils. J Herbs Spices Med Plants
Lis-Balchin M, Deans S, Hart S. Bioactivity of New Zealand
medicinal plant essential oils. Acta Horticult 1996;426:
Lis-Balchin M, Hart SL, Deans SG. Pharmacological and antimi-
crobial studies on different tea tree oils (Melaleuca alterni-
folia,Leptospermum scoparium or Manuka and Kunzea
ericoides or Kanuka) originating in Australia and New
Zealand. Phytother Res 2000;14(8):623–9.
Perry NB, Brennan NJ, van Klink JW, Harris W, Douglas MH,
McGimpsey J. Essential oils from New Zealand manuka and
kanuka. Chemotaxonomy Leptospermum 1997;44:1485–94.
Porter N. Manuka the good oil from New Zealand. HerbalGram
Porter NG, Smale PE, Nelson MA, Hay AJ, van Klink JW, Dean CM.
Variability in essential oil chemistry and plant morphology
within Leptospermum scoparium population. New Zeal J Bot
Porter NG, Wilkins AL. Chemical, physical and anti-microbial
properties of essential oils of Leptospermum scoparium and
kunzea ericodes. Phytochemistry 1999;50(3):407–15.
Rhee GJ, Chung K-S, Kim EH, Sun HJ, Hong ND. Antimicrobial
activities of steam distillate of Leptospermum scoparium.
Yakhak Hoeji 1997;41:132–8.
Sheppard-Hanger S. The aromatherapy practitioner reference
manual, vol. II. Florida: The Atlantic Institute of Aroma-
Tisserand R, Balacs T. Essential oil safety, a guide for health
professionals. UK: Churchill Livingstone; 1995.
van Klink JW, Brophy JJ, Perry NB, Weavers RT. B-triketones
from Myrtaceae: isoleptospermone from Leptospermum
scoparium and papuanone from Corymbia dallachiana.J
Nat Prod 1999;62:487–9 (1999).
Webb MA. Bush sense Australian essential oils & aromatic
compounds. Australia: Grifﬁn Press; 2000.
Webb MA. Australian essential oil proﬁle – Kunzea. Aromather
146 W. Maddocks-Jennings et al.