‘‘Anti-lice Protector Shampoo’’: Clinical Study Shows Lack of Efficacy of Coconut Oil Derivatives in the Elimination of Head Louse Infestation

Abstract

Objective: Coconut oil and its derivatives are widely thought to kill head lice by occlusion and asphyxiation. There is no evidence in support of coconut derivative-based products sold to treat pediculosis. This study was designed to test one such product.
Methods: This was an open-label clinical study in 31 people. The treatment was shampoo containing 1% fractionated coconut oil. Treatment was given on day 0 and day 8. Efficacy was measured using a detection comb on day 1, day 8 and day 16 after the first
treatment. The trial was registered in the current controlled trials database, under number ISRCTN79136319.
Results: The first application of the product eliminated the lice from 7/31 participants, and 12/31 (38.7%) people had no lice at the end of the study. Lice of all development stages were found post treatment at all assessments on one or more participants. This
indicates that the treatment failed to kill all stages of the life cycle of head lice.
Conclusion: Two applications of the modified coconut shampoo were not effective at killing head lice or their eggs. The results confirm other studies that show little intrinsic activity in vegetable oils and modified oils. Most of the activity in shampoos is probably due to other product components, such as high levels of detergents.
Keywords: Head lice, coconut oil, shampoo, therapy

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Original Investigation
DerDergigisisi
PARAZITO LOJI
211
Özgün Araştırma
Turkiye Parazitol Derg 2020;44(4):211-5
ABSTRACT
Cite this article as:
ÖZ
Received/Geliş Tarihi: 18.05.2020 Accepted/Kabul Tarihi: 17.07.2020
Address for Correspondence/Yazar Adresi: Ian Faisal Burgess, Insect Research and Development Limited, Medical Entomology Centre,
Cambridge, England
Phone/Tel: +44 1223 813696 E-mail/E-Posta: ian@insectresearch.com ORCID ID: orcid.org/0000-0003-0747-3938
Amaç: Hindistan cevizi yağı ve türevlerinin, ba bitlerini tıkanma ve boğulma yoluyla öldürdüğü düünülmektedir. Pediculosis
tedavisi için satılan Hindistan cevizi türevi bazlı ürünlerin etkinliğini destekleyici bir kanıt yoktur. Bu çalıma, bu ürünlerden birini
test etmek için tasarlanmıtır.
Yöntemler: Bu çalıma 31 kii üzerinde yapılmıtır. Tedavide %1 oranında parçalanmı Hindistan cevizi yağı içeren ampuan
kullanılmıtır. Tedavi 0. ve 8. günlerde uygulanmıtır. Etkinlik, birinci tedaviden sonraki 1., 8. ve 16. günlerde bit tarağı kullanılarak
ölçülmütür. Deneme, ISRCTN79136319 numaralı mevcut kontrollü denemeler veri tabanına kaydedilmitir.
Bulgular: Ürünün ilk uygulamasıyla, 31 katılımcının yedisi bitlerden temizlenmi ve çalımanın sonunda ise 31 kiiden 12’sinde
(%38,7) bit kalmamıtı. Tedavi sonrasında, bir veya daha fazla katılımcı üzerinde bitlerin tüm gelime dönemlerine rastlanmıtır.
Bu durum, uygulanan tedavinin ba bitlerini bütün gelime dönemlerinde öldürmediğini göstermektedir.
Sonuç: Değitirilmi Hindistan cevizi ampuanının iki uygulaması, ba bitlerini veya yumurtalarını öldürmek için etkili
olmamıtır. Bu sonuç, bitkisel yağlardan ve modifiye edilmi yağlardan çok az intrinsik aktivite göstermi diğer çalımaları
doğrulamaktadır. ampuanların çoğunun aktiviteleri, muhtemelen yüksek oranda bulunan deter jan gibi diğer ürün bileenlerinden
kaynaklanmaktadır.
Anahtar Kelimeler: Saç biti, hindistan cevizi yağı, ampuan, terapi
Objective: Coconut oil and its derivatives are widely thought to kill head lice by occlusion and asphyxiation. There is no evidence
in support of coconut derivative-based products sold to treat pediculosis. This study was designed to test one such product.
Methods: This was an open-label clinical study in 31 people. The treatment was shampoo containing 1% fractionated coconut oil.
Treatment was given on day 0 and day 8. Efficacy was measured using a detection comb on day 1, day 8 and day 16 after the first
treatment. The trial was registered in the current controlled trials database, under number ISRCTN79136319.
Results: The first application of the product eliminated the lice from 7/31 participants, and 12/31 (38.7%) people had no lice at
the end of the study. Lice of all development stages were found post treatment at all assessments on one or more participants. This
indicates that the treatment failed to kill all stages of the life cycle of head lice.
Conclusion: Two applications of the modified coconut shampoo were not effective at killing head lice or their eggs. The results
confirm other studies that show little intrinsic activity in vegetable oils and modified oils. Most of the activity in shampoos is
probably due to other product components, such as high levels of detergents.
Keywords: Head lice, coconut oil, shampoo, therapy
Burgess IF, Burgess NA. ‘‘Anti-lice Protector Shampoo’’: Clinical Study Shows Lack of Efficacy of Coconut
Oil Derivatives in the Elimination of Head Louse Infestation. Turkiye Parazitol Derg 2020;44(4):211-5.
Insect Research and Development Limited, Medical Entomology Centre, Cambridge, England
Ian Faisal Burgess, Nazma Akhter Burgess
‘‘Anti-lice Protector Shampoo’’: Klinik Çalışma, Hindistan Cevizi Yağı için
Etkinliğin Olmadığını Gösteriyor
‘‘Anti-lice Protector Shampoo’’: Clinical Study
Shows Lack of Efficacy of Coconut Oil Derivatives
in the Elimination of Head Louse Infestation
DOI: 10.4274/tpd.galenos.2020.6361
INTRODUCTION
Numerous products are registered as medical devices
in Europe for treatment or prevention of head louse
infestation. All are sold with claims of efficacy. This
marketing suggests there is supporting evidence for the
claims, although most data have never been published.
In practice, most products only have data from limited
laboratory testing. There is also considerable variation

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212
in the treatment regimens for these products despite never
having been tested clinically. If there is no clinical evidence, it
is likely that claims have been selected to make products appear
more attractive to consumers.
A previous investigation evaluated the efficacy of a shampoo
product claimed to be based on soya oil (1). It was subsequently
discovered that the product tested did not contain any oil, and
observed activity was attributed to the high concentration of
surfactants in the product (2). This report describes a clinical
investigation of a shampoo product originating from the same
product development source. Most of the efficacy claims were
essentially similar to those for the “soya” shampoo and this study
was performed to determine whether the two products exhibited
similar activity.
METHODS
Study Design
This was a single-centre, non-randomised, single-arm, open-
label study conducted in conformity with the principles of Good
Clinical Practice and the Declaration of Helsinki. Ethical approval
was granted by Cambridgeshire 1 Research Ethics Committee.
reference 10/H0304/95. The trial was registered with the ISRCTN
registry, number ISRCTN79136319 prior to commencement.
Recruitment of participants was by advertising in local news
media. Respondents to the advertising were sent an information
booklet describing the treatment and study procedures. When
the study centre was contacted, after prospective participants had
read the information, an appointment was made for a domiciliary
visit by an investigator. All study procedures were performed
during visits to participants at home using methods described
previously (1,3). The first stage of the recruitment process was
for participants, or their parent/guardians to sign a consent form.
Children younger than 16 years of age also provided written
assent.
Participants were checked for an active head louse infestation
by detection combing prior to treatment on day 0. No count
of lice or louse eggs was made at the time of enrolment but the
level of infestation was described by how quickly lice were found
during combing: heavy infestation = >1 louse with one stroke
of the comb; moderate infestation =1 louse with one stroke of
the comb; light infestation = first louse found only after several
strokes of the comb. Participants confirmed they had had no nut
related allergies, were not pregnant, and had not been treated
with pediculicides for 2 weeks or with trimethoprim containing
products for 4 weeks prior to entry.
Treatment and Follow-up
The test product, Anti-lice Protector (LHS Institut, St. Florian,
Austria) consisting of 1% fractionated coconut oil in an aqueous
shampoo basis, was provided in numbered bottles each containing
100 mL of shampoo. Each bottle was shaken thoroughly
immediately before use because it was found to physically
separate on standing. The product, applied to pre-wetted hair,
was first used like an ordinary shampoo to clean the hair, rinsed,
and partially towel dried. A greater quantity was then applied
to the damp hair, sufficient that, when thoroughly massaged, it
produced a homogeneous and stable foam that covered all the
hair and scalp. If insufficient stable foam was built, more of the
shampoo was applied, using more than one bottle if necessary. The
foamed product was left in place for 15 minutes, after which the
hair was rinsed with warm water. A second treatment was applied
using the same methodology after the follow-up examination on
day 8.
After treatment we assessed for persistent infestation using
a plastic head louse detection comb (PDC, KSL Consulting,
Helsinge, Denmark) during follow-up visits on day 1, day 8 before
application of the second treatment, and a final outcome check
on day 16. On each occasion the whole hair and scalp was combed
systematically and any lice recovered collected into the case
record. At each treatment or follow-up examination any adverse
experiences, whether or not due to the investigative product,
were recorded.
Statistical Analysis
Analyses were planned for both the ‘‘intention-to-treat’’ and the
‘‘per-protocol’’ populations. For demographic characteristics the
study group was compared with study groups from previous studies
for comparability and generalizability of baseline characteristics,
safety, acceptability and efficacy using Fisher’s Exact test for yes/
no variables and the Mann-Whitney U test for ranked variables.
Analyses were performed using the online calculators available at
https://www.socscistatistics.com/. If analysis showed important
differences in baseline characteristics, chi-squared and rank tests
stratified for these characteristics could also be conducted.
RESULTS
The study enrolled 31 participants from 18 families, with ages
ranging from 2-43 years (median 8 years), between 1st April
and 17th June 2011. Of the participating families, 2, 3, or 6
members were represented by two households each; there were
four households with 5 members, seven with 4 occupants, and
one household with 9 members. Eleven of these households
were represented by only one participant (Table 1). Twenty-four
(77.4%) participants were female. The age structure of this cohort
was not significantly different from previous studies, with 19.4%
participants aged between 2 and 5 years, 41.9% in the 6-9 years
age group, and 29% aged 10-15 years. Three participants were
over 16, aged 37, 38, and 43 years (Table 2).
Other demographic characteristics such as hair length, thickness,
degree of curl, and dryness/greasiness were similar to groups
observed in previous studies. In this study the proportion of
participants with infestations designated as heavy and moderate
(48.4%) was significantly (p<0.05) higher than found in some
previous studies conducted in the same community (Table 2).
However, in most cases, the actual intensity of infestation was
probably greater than indicated by this semi-subjective measure.
There was no identifiable relationship between intensity of
infestation and hair length or thickness.
Follow up detection combing of participants was designed to
not only measure the initial therapeutic impact of treatment but
also to look for nymphs emerging from eggs not killed by the
treatment. All participants had the presence of lice confirmed at
day 0 and all had some viable eggs in their hair. All participants
except one completed the study (Figure 1). The only withdrawal
was participant 01, on grounds of non-compliance, after the
child’s grandmother treated with 4% dimeticone lotion before the
day 8 checkup and the second treatment.

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After the first treatment no lice were found on 10 participants,
each from a different family. All others had lice present, ranging
from one to 62 insects collected on day 1. Lice from each life cycle
stage were present on one or more individuals showing that,
apart from a few nymphs that hatched since treatment, lice of all
development stages were able to survive this treatment. A similar
pattern was observed in the pre-treatment assessment on day 8
(Table 1). Following the second treatment, sufficient time elapsed
for any surviving eggs to hatch before the final assessment on day
16. At this assessment 12/30 (40%) participants were found to be
louse free, nine of whom had been louse free on day 1. All other
participants showed one or more lice at day 16 and were classified
as treatment failures. Consequently, the rate of cure, the primary
outcome variable, for the intention to treat group was 38.7%
(12/31) and 41.3% (12/29) for the per-protocol group (Figure
1). The cure rate following first treatment was 7/31 (22.6%). In
general, the same pattern of infestation was observed throughout,
with those people having larger numbers of lice on days 1 and 8
also showing larger numbers of lice on day 16 (Table 1).
All participants except 01 received two treatments using anti-
lice protector shampoo. For 18 participants each treatment
involved only one bottle. The others received two bottles for one
or both treatments. Mean use for the first treatment was 78.9g
(standard error 7.7 g) with variation between 22.4 g and 155.9 g.
The weight of product used for the second treatment was similar
in most cases, mean 77.8 g (standard error 8.6 g) with a range
from 8.9 g to 160.8 g. There was no correlation between the
quantity of shampoo used and the success rate for eliminating the
infestation. Paradoxically, the mean quantity of shampoo used on
those participants successfully treated (135.5 g) was about half
that used on those whose treatment was not effective (263.0 g)
and was likely more a reflection of the high proportion of males
and older participants in the success group (Table 1).
Adverse Events
There were 17 reported adverse events related to treatment but
no serious adverse events. Fifteen reported adverse events in nine
people were variable levels of stinging, burning, or intense itching
sensation of the scalp during the period that the treatment was in
situ. All were recorded as “mild” in intensity except one which was
recorded as “severe”. In addition, one participant experienced a
coughing fit possibly related to treatment during washing off the
second shampoo treatment and another experienced dryness of
the scalp for several days after completion of treatment.
DISCUSSION
This study has been to investigate the efficacy of a shampoo
containing 1% fractionated coconut oil, which is most widely
recognised as caprylic/capric triglyceride, a light and stable
manufactured emollient that is miscible with oils or readily
emulsifiable with surfactants. This material is a component of
several head louse treatment shampoos that indicate “coconut oil”
on the list of ingredients and claim to “suffocate” or “asphyxiate”
the lice. However, evidence for efficacy of these shampoos is scant
despite claims that they are “clinically tested” with no indication
of whether or where any proper objective tests may have been
conducted. One shampoo, listed as a coconut-derived emulsion,
was tested in a school-based clinical study and obtained a success
rate by intention to treat of 22/41 (53.7%) at day 15 after two
Figure 1. Flowchart of participants through the study

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214
treatments one week apart (4), a result that was not significantly
different from this study (Z= -1.258, p=0.20766).
A different type of product based on modified coconut oil, anise,
and ylang-ylang with marketing claims that it had an asphyxiant
effect derived most of its activity from the anise component
(approximately 12% anethole) a well-recognised insecticide in
other applications. Consequently, any claims for an occlusive
action by the “coconut” component made by the manufacturer in
relation to efficacy obtained in two studies comparing the product
with insecticides (5,6) were likely spurious and inaccurate. Even
whole coconut oil (melting point ~24o Celsius) was shown ex
vivo to have little activity until 4 hours had elapsed, eventually
achieving 90% louse kill (7). In contrast, olive oil, which is mainly
made up of unsaturated fats with a similar carbon chain length
to those of coconut oil, was found to kill only 2% of lice after 8
hours (8).
Irrespective of its chemical form, there is no evidence that small
concentrations of either pure or modified fixed vegetable oils
can have an effect on head lice, yet an internet search using
the term “head lice vegetable oil” provided 1,830,00 responses,
many of which were either advocating use of oils to kill lice or
were advertising products containing oils. In the western world
most people are unaware that coconut and similar oils have been
regularly used over centuries as hair conditioning agents in much
of Asia, Africa, and parts of the Americas, but the people using
them can still have head lice. Based on the similarity between the
Table 1. Dstrbuton of partcpants by household, nfestaton level, lce found per study day, and outcome of treatment
Partcpant
number/gender Household No. n house Infestaton Number of lce found Outcome
Day 1 Day 8 Day 16
01 F 1 2 Heavy 1 9 NC Not cured
02 F 2 9 Moderate 3 3 2 Not cured
03 M - - Heavy 11 1 3 Not cured
04 F - - Heavy 11 12 27 Not cured
05 F - - Moderate 28 6 6 Not cured
06 M - - Moderate 0 0 0 Cured
07 M 3 5 Light 0 1 0 Cured
08 M 4 3 Light 0 0 0 Cured
09 F 5 5 Light 0 0 0 Cured
10 F - - Moderate n/a 12 13 Not cured
11 F 6 2 Moderate 4 16 35 Not cured
12 F - - Light 0 1 3 Not cured
13 F 7 6 Moderate 5 4 6 Not cured
14 F 8 4 Light 0 0 0 Cured
15 F 9 6 Light 0 0 0 Cured
16 F 10 5 Light 7 2 11 Not cured
17 F 11 4 Moderate 14 1 0 Cured
18 M - - Light 3 4 10 Not cured
19 F 12 4 Light 0 1 0 Cured
20 M - - Light 2 3 0 Cured
21 M - - Light 3 4 0 Cured
22 F 13 4 Light 0 0 0 Cured
23 F 14 3 Heavy 62 6 36 Not cured
24 F 15 5 Heavy 17 8 8 Not cured
25 F - - Light 0 0 0 Cured
26 F 16 4 Light 9 18 17 Not cured
27 F 17 4 Heavy 4 6 6 Not cured
28 F - - Light 2 5 5 Not cured
29 F - - Moderate 21 56 30 Not cured
30 F - - Moderate 9 13 26 Not cured
31 F 18 4 Light 1 4 4 Not cured
NC: Non-complant and wthdrawn, n/a: Not avalable for checkng on that day

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Turkiye Parazitol Derg 2020;44(4):211-5
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shampoo formulation used in this study and that tested previously
under the guise of a soya-based shampoo, it is likely that what
efficacy was observed in this study was due to the high surfactant
levels in the product rather than any effect of the caprylic/capric
triglyceride.
CONCLUSION
This study has shown that a modified coconut oil shampoo has a
limited effect to adequately treat head louse infestation with only
41.3% success in the per-protocol population. This result supports
other reported outcomes using similar preparations in which
vegetable oils and their derivatives showed little efficacy beyond
that which could be imputed to the formulation excipients, such
as surfactants included at relatively high concentrations.
ACKNOWLEDGEMENT
Dr Paul Silverston provided medical supervision for clinical
queries. Elizabeth Brunton and Ben Hall performed some post
treatment assessments.
* Ethcs
Ethcs Commttee Approval: Ethical approval was granted
by Cambridgeshire 1 Research Ethic Committee reference 10/
H0304/95.
Informed Consent: Written consent was obtained.
Peer-revew: Internally peer-reviewed.
* Authorshp Contrbutons
Concept: I.F.B., Design: I.F.B., N.A.B., Data Collection or Processing:
I.F.B., N.A.B., Analysis or Interpretation: I.F.B., Literature Search:
I.F.B., Writing: I.F.B.
Conflct of Interest: No conflict of interest was declared by the
authors.
Fnancal Dsclosure: The clinical study was commercially
funded and clinical supplies provided by LHS Institut, St Florian,
Austria and Fulltec AG, Zug, Switzerland. The decision to publish
was that of the authors and no funding was received for this work.
REFERENCES
1. Burgess IF, Kay K, Burgess NA, Brunton ER. Soya oil based shampoo
superior to 0.5% permethrin lotion against head louse infestation. Med
Devices (Auckl) 2011; 4: 35-42.
2. Burgess IF. Soya oil based shampoo superior to 0.5% permethrin lotion
against head louse infestation [Corrigendum]. Med Devices (Auckl) 2015;
8: 295-6.
3. Burgess IF, Lee PN, Matlock G. Randomised, controlled, assessor blind
trial comparing 4% dimeticone lotion with 0.5% malathion liquid for head
louse infestation. PLoS ONE 2007; 2: e1127.
4. Connolly M, Stafford KA, Coles GC, Kennedy CTC, Downs AMR. Control
of head lice with a coconut-derived emulsion shampoo. J Eur Acad
Dermatol Venereol 2009; 23: 67-9.
5. Mumcuoglu KY, Miller J, Zamir C, Zentner G, Helbin V, Ingber A. The in
vivo pediculicidal efficacy of a natural remedy. Isr Med Assoc J 2002; 4:
790-3.
6. Burgess IF, Brunton ER, Burgess NA. Clinical trial showing superiority of
a coconut and anise spray over permethrin 0.43% lotion for head louse
infestation, ISRCTN96469780. Eur J Pediatr 2010; 69: 55-62.
7. Asenov A, Oliveira FA, Speare R, Liesenfeld O, Hengge UR, Heukelbach
J. Efficacy of chemical and botanical over-the-counter pediculicides
available in Brazil, and off-label treatments, against head lice ex vivo. Int
J Dermatol 2010; 49: 324-30.
8. Takano-Lee M, Edman JD, Mullens BA, Clark JM. Home remedies to
control head lice: assessment of home remedies to control the human
head louse, Pediculus humanus capitis (Anoplura: Pediculidae). J Pediatr
Nurs 2004; 19: 393-8.
Table 2. Demographc characterstcs of partcpants and
treatment success by characterstc
Characterstc Number
(percent)
Treatment
success (percent)
Number of participants 31 12 (38.7%)
Age
2-5 6 (19.4%) 3 (50.0%)
6-9 13 (41.9%) 3 (23.1%)
10-15 9 (29.0%) 5 (55.6%)
>16 3 (9.7%) 1 (33.3%)
- - -
Median 8 -
- - -
Gender
Male 7 (22.6%) 5 (71.4%)
Female 24 (77.4%) 7 (29.2%)
- - -
Previous treatment experience
Ever used head louse
treatment 27 (87.1%) 8 (29.6%)
Previous treatment
successful 10 (32.3%) 4 (40.0%)
Hair characteristics
Length
Above ears 7 (22.6%) 5 (71.4%)
Ears to
shoulders 7 (22.6%) 2 (28.6%)
Below
shoulders 17 (54.8%) 5 (29.4%)
Thickness
Fine 5 (16.1%) 3 (60.0%)
Medium 19 (61.3%) 5 (26.3%)
Thick 7 (22.6%) 4 (57.1%)
- - -
Curl
Straight 26 (83.9%) 8 (30.8%)
Wavy/curly 5 (16.1%) 4 (80.0%)
- - -
Infestation characteristics
Light 16 (51.6%) 10 (62.5%)
Medium 9 (29.0%) 2 (22.2%)
Heavy 6 (19.4%) 0 (0.0%)