The effect of dietary intake of coenzyme Q10
on skin parameters and condition: Results of
a randomised, placebo-controlled,
VIST—Higher School of Applied Sciences, Institute of Cosmetics, Ljubljana,
Nutrition Institute, Ljubljana, Slovenia
Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
Coenzyme Q10 (CoQ10) is a natural constituent of foods and is
also often used in both functional foods and supplements. In
addition, it is a common ingredient of cosmetics where it is
believed to reduce the signs of skin ageing. However, the existing
data about the effect of dietary intake of CoQ10 on skin parame-
ters and condition are scarce. To gain an insight into this issue,
we conducted a double-blind, placebo-controlled experiment
with 33 healthy subjects. Our objective was to investigate the
effects of 12 weeks of daily supplementation with 50 and 150 mg
of CoQ10 on skin parameters and condition. Study was
conducted with a water-soluble form of CoQ10 with superior bio-
). While the results of some previous in vitro
studies showed possible protection in UVB response, we did not
observe signiﬁcant changes in the minimal erythema dose
(MED). On the other hand, the intake of CoQ10 limited seasonal
deterioration of viscoelasticity and reduced some visible signs of
ageing. We determined signiﬁcantly reduced wrinkles and micro-
relief lines, and improved skin smoothness. Supplementation
with CoQ10 did not signiﬁcantly affect skin hydration and dermis
C2016 BioFactors, 00(00):000-000, 2016
Keywords: Coenzyme Q10; CoQ10; antioxidant; skin health; anti-ageing
Coenzyme Q10 (CoQ10) is an endogenous lipophilic compound,
an essential component of the mitochondrial energy metabo-
lism  and an effective antioxidant with a range of possible
beneﬁts for human health [2–4]. The presence of CoQ10 in the
membranes of eukaryotic cells suggests its potential to act as
an antioxidant and scavenge free radicals, preventing the
activation of inﬂammatory signalling pathways . The beneﬁ-
cial role of CoQ10 supplementation has been reported in vari-
ous conditions, particularly in cardiovascular [6–8], neurode-
generative and mitochondrial conditions [9–11], diabetes ,
periodontal disease , and male infertility .
The human body biosynthesises CoQ10, but its skin levels,
as well as its levels in other tissues, drop progressively with
increasing age [15,16]. CoQ10 is also supplied to the organism
by exogenous sources, for example, foods. The richest dietary
sources are meat, migratory ﬁsh, nuts, and some oils, but in
the diet of populations of Western countries these sources
altogether contribute to just 3–5 mg CoQ10 per day .
Further, CoQ10 deﬁciency has been observed in some medical
conditions , in persons with inadequate nutrition and in
smokers . It has also been shown that the endogenous
synthesis of CoQ10 is inhibited by cholesterol-lowering statin
drugs, which inhibit biosynthesis of mevalonate, and CoQ10
supplementation has therefore been suggested in such cases
C2016 International Union of Biochemistry and Molecular Biology
Volume 00, Number 00, Month/Month 2016, Pages 00–00
*Address for Correspondence: Assist. Prof. Katja
zmitek, PhD, VIST –
Higher School of Applied Sciences, Institute of Cosmetics, Gerbic
Ljubljana, Slovenia; E-mail: email@example.com, Tel.: 1386 1 283 17 00;
Fax: 1386 1 283 17 01
Received 15 April 2016; accepted 20 July 2016
Published online 00 Month 2016 in Wiley Online Library
Skin is the outermost human organ that is in direct contact
with the environment and thus constantly exposed to external
stress factors. In the skin, CoQ10 is found in both cells and
skin surface lipids (SSL), a constituent of the stratum corneum,
where it acts in combination with other substances as the
skin’s outermost barrier to oxidant assault [23,24]. CoQ10 is
also crucial in maintaining mitochondrial activity in cells. It
has been shown that CoQ10 levels in skin and skin surface
lipids decline with age [15,24,25].
In the last decade, we have seen increased use of CoQ10
in health-related products. Even though in the European Union
there are no authorized health claims regarding CoQ10 as a
functional food ingredient, it is mostly used in products
intended to support heart health. This can be explained by the
fact that the strongest evidence is available for the beneﬁcial
role of CoQ10 supplementation in cardiovascular health [6–8]
but, considering that studies were not performed on healthy
population groups, such evidence cannot be used to substanti-
ate health claims for foods . On the market, CoQ10 is
mainly used in food supplements , although it can also be
found in functional foods. For example, CoQ10 was added as a
functional ingredient to 3.5% of yoghurts sold in the Slovenian
food supply in 2011 . Recommended daily dosages in
food supplements usually vary from 50 to 150 mg, however
products with higher levels are also available.
In addition to such use, CoQ10 is also commonly added to
cosmetics, chieﬂy due to its perceived ability to protect the
skin from free radical damage and reduce signs of ageing. As
shown by several in vitro experiments, CoQ10 is able to pro-
tect the skin from reactive oxidative species (ROS), induce the
proliferation of skin ﬁbroblasts, inhibit MMP-1 enzymes that
degrade extracellular matrix components, accelerate the pro-
duction of epidermal basement membrane components, reduce
DNA damage triggered by UVA irradiation, decrease UVR-
induced inﬂammatory response and lower levels of superoxide
generation by ArNOX proteins [29–34]. There are also some
studies showing beneﬁcial effects of topical CoQ10 use on skin
in vivo. Knott et al. very recently showed that topical applica-
tion of CoQ10 raises its epidermal content in both SSL and
deeper layers of the epidermis and improves the skin’s antioxi-
dant potential . Improvement of the antioxidant potential
of the skin by topical CoQ10 application was also shown by
Vinson et al. . Hoppe et al. showed that three months of
topical CoQ10 application decreased wrinkle depth in human
skin , but statistical data for these effects were not pro-
vided. A clinical trial involving 31 females demonstrated a
reduction in wrinkle score after using CoQ10 cream for 5
months . A clinical trial by McDaniel with idebenone (a
synthetic CoQ10 analog) lotion showed an increase of collagen
I expression and improvement in skin roughness, wrinkles and
ﬁne lines, but a vehicle control group was lacking .
Supported by this evidence, along with very strong mar-
keting campaigns of the cosmetics industry, CoQ10 has also
become an interesting functional food ingredient in so-called
beauty products, formulated to support skin health. However,
the existing data about the effect of dietary intake of CoQ10 on
skin parameters and condition is scarce . Passi et al.
showed that joint oral and topical use of CoQ10 in combination
with vitamin E is able to raise CoQ10 levels in skin and reduce
wrinkle depth , but to our knowledge no reports in the sci-
entiﬁc literature assess the efﬁciency of dietary CoQ10 alone.
In comparison to topical application, where skin barrier limits
penetration of the CoQ10, oral intake could deliver this com-
pound more efﬁciently into the dermis, skin layer responsible
for skin elasticity and ﬁrmness among others.
To gain an insight into the effect of dietary intake of coenzyme
Q10 on skin parameters and condition, we conducted a double-
blind, placebo-controlled experiment with 33 healthy volunteers.
Our objective was to investigate the effects of 12 weeks’ dietary
supplementation CoQ10 on erythema response to UVB, visible
signs of ageing—wrinkles and skin microrelief, skin hydration
and elasticity, and dermis condition.
2.1. Design of the Study
Thirty-three healthy Caucasian female volunteers, ranging in
age from 45 to 60 years (mean age 52.6 64.2 (SD)) with
Fitzpatrick skin phototypes II and III were enrolled in the study
after providing written consent. Inclusion criteria were signs of
skin ageing (mimic wrinkles/poor skin tone/visual dryness),
photo-aged skin on the face, and expression of mimic wrinkles.
Exclusion criteria were pregnancy or breastfeeding, a known or
suspected allergy to any ingredient of the tested products, high
blood cholesterol and use of cholesterol-lowering medicines,
diagnosed diabetes, thyroid disease, inﬂammatory skin diseases,
regular use of dietary supplements (including products with
added CoQ10) in last 6 months preceding study entry, invasive
(Botox injections, hyaluronic acid ﬁllers, needle rollers, needle
mesotherapy, etc.) and noninvasive (radiofrequency, electro-
therapy, ultrasound therapy, etc.) rejuvenation treatments in
last 6 months prior to study entry, the use of cosmetic products
containing CoQ10 in last 6 months preceding study entry, and
gluteal hyperpigmentation. Subjects were also asked not to
change their routinely used skin care regime on the test sides
during the entire study period. Further, subjects were asked to
continue their normal dietary habits. Additional dietary supple-
ments, sunbathing and use of tanning machines were not
allowed during the 12-week intervention trial. Consistent with
the principles laid down in the Declaration of Helsinki, all sub-
jects provided signed informed consent before recruitment. The
study was approved by the Ethics Committee of the Higher
School of Applied Sciences, and included in the ClinicalTrials.gov
register under record NCT02604641.
Subjects were randomly assigned to either: (a) a placebo
group (mean age 52 64 years); (b) a low-dose group (LD
group; 54 64 years) receiving 50 mg of CoQ10/day; or (c) a
high-dose group (HD group; mean age 52 65 years) receiving
150 mg of CoQ10/day; with 11 subjects per group.
2The Effect of Dietary Intake of Coenzyme Q10 on Skin Parameters and Condition
Out of 33 subjects enrolled in the study, 32 completed the
entire 12-week trial (HD group: 10 subjects, LD and placebo
group: 11 subjects each), there was one drop-out in the HD
group before regular check after 6 weeks.
All subjects consumed 5 mL of a syrup daily for 12 weeks. The
placebo group received an aqueous syrup formulation without
CoQ10 (placebo), the LD group received test syrup with 50 mg
of CoQ10 per 5 mL, and the HD group received test syrup with
150 mg of CoQ10 per 5 mL (Fig. 1). To enable the production
of aqueous syrup with CoQ10, a water-soluble form of CoQ10
was used in the formulations (Q10Vital
as used in Quvital
food supplements, Valens Int. d.o.o., Slovenia) [39,40].
Improved bioavailability of this constituent was previously
reported . All three syrups were formulated and produced
by Valens Int. d.o.o. Syrup base contents were sugar, water,
apple juice concentrate, sodium benzoate (preservative), citric
acid, and apple ﬂavor. In test syrups CoQ10 (Q10Vital
added to this base, while placebo syrup was coloured with
food colouring agents (E102, E110) and thickened using modi-
ﬁed starch to achieve organoleptic characteristic, comparable
to test syrups. No other known anti-aging ingredients but
CoQ10 were employed in the tested formulation, and therefore,
any increase in efﬁcacy over the placebo could be reasonably
attributed to the CoQ10. To assure the proper CoQ10 concen-
tration, all three variations of the syrup samples were also
sent for testing to an independent laboratory (Chelab S.r.l,
Resana, Italy), where the CoQ10 concentration was determined
using standard high-performance liquid chromatography .
To monitor subjects’ compliance with the instructions the sub-
jects were asked to record daily intake of a syrup; diaries
were checked at their visits after 6 and 12 weeks. Subjects
were also asked to record any failure to comply with the
instructions. At the last evaluation term they were required to
return leftover test products.
Regular checks of the subjects were carried out three times dur-
ing the study: at the baseline (week 0), after 6 weeks (week 6)
and after 12 weeks of supplementation (week 12) and Visioface
images of the face were recorded at those times. Changes of der-
mis ultrasonic echogenicity and thickness as well as skin surface
parameters (hydration, viscoelasticity) were measured on the
face at week 0 and week 12. The minimal erythema dose (MED)
was determined on a gluteal area at week 0 and week 12.
Wrinkle area fraction measurements were performed on the
face using the Visioface CSI system and additionally assessed
according to the Lemperle scale at week 0 and week 12. Results
were obtained during a period of colder outside temperatures
and low sun exposure from November 2014 to January 2015;
average monthly temp. 8.88C, 3.98C, and 2.88C, respectively.
All measurements were carried out on subjects lying in a room
with a temperature of 20–258C and relative humidity 40–60%,
except the Visioface imaging was done in a sitting position.
Measurements started after a 30 Min acclimatization period in
the same atmospheric conditions. Subjects were advised to clean
their face at least 2 H before the time of measurement and to not
apply any cosmetic products on their face 2 H or less before the
2.2.1. Skin viscoelasticity and hydration measurements,
ultrasound measurements of dermis thickness and density
Viscoelasticity measurements were performed on a predeter-
mined position of the right cheek using a Cortex Technology
DermaLab Combo SkinLab elasticity probe (Cortex Technology,
Hadsund, Denmark). The measurement gives results in MPa.
Hydration measurements were performed on a predeter-
mined area of the right cheek using a Cortex Technology Derma-
Lab Combo SkinLab hydration probe, which operates on the
conductivity principle. Eight consecutive measurements were
conducted and the result for each subject is the average of them.
The measurement gives results in lS.
Ultrasound measurements of dermis thickness and density
were performed using a Derma-Lab
Combo SkinLab USB 20 MHz
high-resolution ultrasound scanner probe (Cortex Technology,
Hadsund, Denmark). A constant gain curve was applied for each
volunteer and dermis thickness and intensity (density) were deter-
mined as published elsewhere . Measurements were carried
is measured in lm and intensity as a 0–100 score.
2.2.2. Photography, wrinkle measurements and
evaluation, skin surface evaluations
High-resolution lateral (left and right) and frontal images of
the face (10 Mpx) were taken using the VisioFace Quick system
(Courage 1Khazaka electronic GmbH, Germany), with a con-
stant distance from the camera in standardized white light
after the subject had placed her face to the front or to the side
in a light facial booth. The diodes illuminate the face evenly.
Flow diagram showing the study design and sub-
jects’ assignment and progression through the trial.
Zmitek et al. 3
The camera and lights were both software-controlled and
immediately ready for use. Because the topography of the skin
varies signiﬁcantly within a few millimeters, the exact location
of the face was obtained by carefully comparing details on the
face with the baseline image, repositioning the face position in
the apparatus in order to obtain a precisely exactly matching
picture of the face. The wrinkle area fraction (wrinkle area
divided by the assessment area) of periorbital wrinkles was
measured for each subject at the baseline and after 12 weeks
using the VisioFace CSI software.
Wrinkle assessment was performed for six different
wrinkle types in different face areas using frontal and lateral
Visioface images by experienced professionals at week 0 and
week 12 according to the Lemperle scale (0–5) . When
evaluating each wrinkle type, only those subjects who had
expressed wrinkles of the observed type at the baseline were
Evaluation of subjects’ skin smoothness and microrelief
was also conducted at week 0 and week 12 by a comparison of
the Visoface images of the face (frontal, left lateral, and right
lateral). The 96 pairs of photographs were assessed using a 3-
grade scale (21: deterioration, 0: no change, 11: improvement)
by experienced professionals. Photographs for week 0 and week
12 were presented in a blind and randomized sequence for each
Skin ﬁrmness was assessed by self-evaluations at week
0 and week 12 using a 3-grade scale (21: deterioration, 0: no
change, 11: improvement).
At the baseline and after 12 weeks, the minimal UVB erythema
dose (MED) was assessed using an automated MED Tester
80 MED Tester, Dr Hoenle Medizintechnik GmbH,
Germany; UVB 280–320 nm). Increasing UV doses (exact dos-
ages depending on the individual’s skin phototype following the
Fitzpatrick classiﬁcation) were applied on a gluteal area through
means of 10 small round apertures within the MED tester.
MED readings were taken 24 H after the application of UV,
with the MED being deﬁned as the lowest dose of UV resulting in
visible erythema of the skin. The UV dose is given in J/cm
application of skin care products on the gluteal area 12 H before
and 24 H after the UV application was allowed.
2.3. Statistical Methods
Data were analyzed using the XLStat statistical software pack-
age (Addinsoft, Barcelona, Spain, version 2016.02.28719). All
the data measured are shown as the mean 6standard error
(SE). Paired t-test or the Wilcoxon signed rank test (for
nonparametric variables) was used to compare baseline values
and values during the supplementation in each group. The
mean percentage change from the baseline was determined.
For comparisons between groups the data were analyzed using
one-way ANOVA with Tukey-Kramer post-hoc test or (for non-
parametric variables) Kruskal-Wallis test with Dunn post-hoc
test to determine signiﬁcant differences between groups.
P<0.05 was considered as statistically signiﬁcance.
3. Results and Discussion
Out of the 33 subjects enrolled in the study, 32 completed the
entire 12-week trial. One subject in the HD group withdrew
before regular check after 6 weeks for nonrelated reasons, and
the results for 32 subjects were analyzed. None had to leave the
study because of adverse events or serious side effects. No side
effects of any kind were reported.
Sunburn (UV-induced erythema) is a result of excessive expo-
sure of the skin to sunlight, particularly UVB irradiation.
Photochemical reactions in the skin lead to increased concen-
trations of reactive oxygen species (ROS), which stimulate
the inﬂammatory pathways . UV-induced erythema starts
to develop within a few hours, peaking about 18–24 H post
exposure. MED is deﬁned as the lowest dose of UV producing
detectable visible erythema of the skin 24 H after the exposure
[45,46]. It is a measure of individual sensitivity to erythemato-
genic UV exposure. It varies between individuals and depends
on the actual endogenic protection. MED measurements were
used to show in vivo photoprotective effects for a number of
dietary antioxidants, for example, ascorbate, carotenoids, and
tocopherols . While no such data are available for CoQ10,
in vitro studies have shown that CoQ10 is able to decrease
UV-induced damage and inﬂammatory response [29,47,48]. On
the other hand, no photoprotective effects of CoQ10 were
observed for in vivo topical applications .
In our study, the MED was slightly reduced from the baseline
at the end of the study period in the placebo group (placebo:
60.05 at the baseline vs. 0.62 J=cm
60.04 at week
12, P50.64) while it was slightly increased in both CoQ10
groups (LD group: 0.69 J=cm
60.08 at the baseline vs.
60.06 at week 12, P50.36; HD group:
60.06 at the baseline vs. 0.70 J=cm
60.06 at week
12, P50.32), but those changes were not signiﬁcant in either of
the groups (Fig. 2). An intergroup comparison between the
placebo, the LD or HD groups also did not show any signiﬁcant
differences (P50.49). Consequently, based on these results we
could not conﬁrm an in vivo anti-inﬂammatory effect of CoQ10
as previously shown for UV response in in vitro studies
[29,47,48]. It should be noted that while conducting a study with
a higher number of subjects or a longer supplementation period
might result in signiﬁcant changes in MED, based on the results
reported herein the expected increase in MED would still be
minor. Moreover, the increase in the dosage of CoQ10 supple-
mentation did not have an important inﬂuence on MED. One
reason that CoQ10 did not provide photoprotective effects could
lie in its sensitivity to UV exposure, which has previously been
shown on a skin model .
3.2. Wrinkle Assessments
The effect of CoQ10 supplementation on wrinkle expression
was assessed in the periorbital area. Measurements of perior-
bital wrinkle area fraction show no signiﬁcant change in the
placebo group (0.580 60.065 baseline vs. 0.579 60.065 at
4The Effect of Dietary Intake of Coenzyme Q10 on Skin Parameters and Condition
week 12, P50.92) while there was a signiﬁcant improvement
in both CoQ10 groups (Fig. 3). In the LD group, wrinkle area
fraction was reduced from 0.575 60.077 at the baseline to
0.509 60.074 at week 12 (P50.02) and in the HD group it
was reduced from 0.492 60.070 at the baseline to
0.442 60.070 at week 12 (P50.02). The intergroup compari-
son of the LD and HD groups also shows a signiﬁcant reduc-
tion in the wrinkle area in comparison to the placebo
(P50.04 for the LD and 0.04 for the HD group vs. placebo)
(Fig. 3). However, there is no signiﬁcant difference in relative
change of the wrinkle area fraction over the 12-weeks of sup-
plementation between the HD and LD groups (P50.99).
The inﬂuence of CoQ10 on periorbital wrinkles and lines
can be observed in Fig. 4 where the periorbital area of two
subjects from the LD (Fig. 4, 1a, 1b) and HD group (Fig. 4, 2a,
2b) before the CoQ10 supplementation (Fig. 4, 1a and 2a) and
after 12 weeks of supplementation (Fig. 3, 1b and 2b) is
shown. After 12 weeks of supplementation, wrinkles are visibly
reduced and an improvement in microrelief lines and smooth-
ness can also be observed.
To provide further insight into the anti-ageing effects of
CoQ10, we performed an expert assessment of wrinkles of
different types in different face areas according to the Lem-
perle scale. Table 1 provides before-after comparisons for
subjects with expressed wrinkles in the selected area at the
baseline. In the placebo group, no signiﬁcant changes in
wrinkle expression were observed for any of the six evaluated
wrinkle types. While we did not observe a dose-response
relationship when wrinkle expression was assessed (using
wrinkle area fraction measurement) in the periorbital area
(Fig. 3), the inclusion of other facial areas showed a notable
improvement when a higher dose of CoQ10 was used. In
addition to signiﬁcant improvements of periorbital (PO) lines
in both the LD and HD groups (in comparison to week 0;
P<0.05), improvements in nasolabial folds (NL), corner of
the mouth lines (CM) and upper radial lip lines (UL) were
noted only in the HD group (P<0.01, <0.01 and <0.05,
3.3. Dermis Thickness and Density
In the placebo group, the average dermis thickness remained
without signiﬁcant change (mean 1461 642 lm at the base-
line vs. 1453 643 lm at week 12; P50.42) as determined
with ultrasound imaging of the dermis. However, there was
also no signiﬁcant change of dermis thickness in either CoQ10
group (LD group: 1494 651 lm at the baseline vs.
1510 647 lm at week 12; P50.31, HD group: 1432 657 lm
at the baseline vs. 1448 653 lm at week 12; P50.16). The
dermis intensity score was also not signiﬁcantly changed for
any of the groups (placebo: mean 27 62 at the baseline vs.
30 63 at week 12; P50.12; LD group: 28 62 at the baseline
vs. 26 62 at week 12; P50.12; HD group: mean 26 62at
the baseline vs. 28 63 at week 12; P50.23). As dermis inten-
sity is related to the amount of properly structured dermal
proteins, for example, collagen and elastin (density), we cannot
conclude that CoQ10 promoted the synthesis or reduced degra-
dation of structural proteins as shown in some in vitro studies
[29,30,32]. Yet we should note that, due to large inter-
personal variations in the baseline dermis intensity, the study
was under-powered to show the effect; a study with over 100
subjects per group would be needed for clear conclusions.
Supplementation over a longer period would also probably be
3.4. Elasticity and Hydration
The measurement of skin viscoelasticity revealed a signiﬁcant
24.5% decrease in the placebo group after the 12-week study
period (P50.03) but, on the other hand, viscoelasticity was
stable in both CoQ10 groups as there was no signiﬁcant
change in viscoelasticity in either of them (P50.69 and 0.24
for the LD and HD groups, respectively) as shown in Table 2.
Inter-group differences of viscoelasticity changes were signiﬁ-
cant between the placebo and both the LD group (P50.03)
and the HD group (P50.03). It is worth noting that the study
Minimal erythema dose (MED, mean 6SE)atthebase-
line and after 12 weeks of CoQ10 supplementation. No
signiﬁcant change was detected in either the placebo or
the CoQ10 groups.
Relative changes in periorbital wrinkle area fraction
for the placebo, LD and HD groups after 12 weeks of
CoQ10 supplementation. Data shown as relative
change of wrinkle area fraction (6SE) in comparison
to baseline values. *P <0.05 signiﬁcant difference
for a comparison of week 12 to week 0;
signiﬁcant difference between groups;
cant difference between groups.
Zmitek et al. 5
was conducted over the late autumn and winter season simul-
taneously for all three groups. As several studies have
conﬁrmed dramatic changes in viscoelasticity and other skin
surface parameters [51,52] during colder winter months, the
obtained results support the positive effects of oral CoQ10 sup-
plementation for limiting negative viscoelasticity seasonal
changes during winter.
In contrast, no signiﬁcant changes in skin hydration (Table
2) were detected in any of the groups. While the dermis is
mostly responsible for skin elasticity, the hydration level of the
skin relates to the hydration level of the epidermis layer and is
therefore not correlated.
3.5. Improvement of Skin Smoothness, Microrelief,
and Skin Firmness in the HD and LD Groups
There was an improvement in skin smoothness as determined
by the expert evaluation in both groups receiving CoQ10,
namely in 70% of subjects in the HD and 82% in the LD group,
Images show the periorbital area of two subjects (both 60 years old) from the LD group (1a, b) and HD group (2a, b) before the
CoQ10 supplementation (week 0, images 1a and 2a) and after 12 weeks of supplementation (images 1b and 2b). Arrows mark
the wrinkles that visibly improved; * marks the area where improvement of smoothness and microrelief lines can be observed.
Wrinkle assessment according to the Lamperle scale (0–5) of HF, horizontal forehead lines; GF, glabellar frown lines; PO,
periorbital lines; NL, nasolabial folds; CM, corner of the mouth lines; UL, upper radial lip lines. Results are given as average
HF GF PO NL CM UL
Week 0 12 0 12 0 12 0 12 0 12 0 12
Placebo 1.3 60.2 1.4 60.2 2.1 60.3 2.1 60.3 2.5 60.2 2.5 60.2 2.0 60.4 2.0 60.4 2.0 60.4 2.0 60.4 1.9 60.4 1.9 60.4
LD Group 2.1 60.4 2.0 60.3 2.9 60.4 3.0 60.4 2.8 60.3 2.4 60.3* 2.9 60.4 2.8 60.4 2.5 60.4 2.4 60.4 1.8 60.3 1.7 60.3
HD Group 1.3 60.2 1.0 60.2 2.6 60.5 2.6 60.5 2.2 60.4 1.7 60.3* 2.8 60.4 2.1 60.5** 2.6 60.4 2.1 60.5** 1.4 60.3 0.6 60.3*
*P<0.05; **P<0.01: Signiﬁcantly different from week 0.
6The Effect of Dietary Intake of Coenzyme Q10 on Skin Parameters and Condition
while in the placebo group there were no subjects with an
improvement in skin smoothness. Similar trends were
observed for microrelief lines as they became notably less
expressed in 64%, 60%, and 9% of subjects in the HD, LD and
placebo groups, respectively.
Average scores of the expert evaluation for changes in skin
smoothness and microrelief lines between week 0 and 12 are
presented in Fig. 5. For both skin smoothness and microrelief,
the changes between the placebo and LD, and the placebo and
HD groups were statistically signiﬁcant, while the difference
between the LD and HD groups was not signiﬁcant. It should be
noted that subjects also reported (by self-evaluation) an
improvement in skin ﬁrmness in 70%, 36%, and 18% of subjects
in the HD, LD, and placebo groups, respectively.
3.6. Study Limitations
It should be noted that some baseline skin parameters are quite
variable and it would therefore be beneﬁcial to perform a study on
a higher number of subjects to allow clearer conclusions regarding
some parameters. For example, the study was under-powered for
dermis parameters (intensity, thickness). Supplementation over a
longer period and several seasons would also be worth testing as
this study was conducted during winter, and also, 12 weeks is quite
a short time to detect nutritional effects on skin, considering the
length of the skin regeneration cycle. Considering this, a longer
study period would also provide valuable insights into dose-
response relationships. While we were unable to show such a rela-
tionship in our study, such an effect might (or might not) be
cycles. It should also be noted that with the intention to minimize
the study’s invasiveness and to assure high compliance rates, this
study was conducted without measuring plasma CoQ10 levels. Due
to inter-individual differences in CoQ10 absorption after supple-
mentation , data on the plasma CoQ10 levels in individuals
might also explain some subject-to-subject differences in this study,
and therefore provide more direct evidence for understanding the
relationship between coenzyme Q10 and skin parameters after
In the present study, the administration of a dietary supple-
ment containing CoQ10 over a 12-week period showed several
anti-ageing effects as it reduced wrinkles, improved skin
smoothness and microrelief as well as skin ﬁrmness. It also
helped the skin combat seasonal changes since it prevented
negative viscoelasticity seasonal changes during winter. The
inﬂuence of the CoQ10 dose on response was observed only in
the expert assessment of wrinkles. While improvement of peri-
orbital wrinkles was comparable for both CoQ10 groups, in
the HD group an additional improvement of wrinkles in other
facial parts (nasolabial folds, corner of the mouth lines and
upper radial lip lines) was observed. There was no signiﬁcant
change of those wrinkles in the LD or placebo group. We were
Skin viscoelasticity and hydration for the placebo, LD and HD groups at the baseline (week 0) and after 12 weeks of CoQ10
Week 0 Week 12 % change P-value*
Placebo 2.15 60.28 1.63 60.23 224.5 0.03
LD Group 1.87 60.28 1.96 60.14 4.8 0.69
HD Group 1.80 60.11 1.97 60.17 9.4 0.24
Placebo 221 617 185 616 216.3 0.06
LD Group 193 615 178 616 27.9 0.17
HD Group 233 619 201 622 213.7 0.16
*Comparison week 12 to week 0.
Average score for changes in smoothness and micro-
relief lines after 12 weeks of CoQ10 supplementation
as determined by the expert evaluation (21: deteriora-
tion, 0: no change, 11: improvement). *P <0.05,
**P <0.01 signiﬁcant difference;
difference between groups.
Zmitek et al. 7
unable to show the effect of the supplementation on skin
hydration, dermis thickness and density. The results also
showed that CoQ10 actually offered little to no photo protec-
tion since it was unable to reduce UVB-induced inﬂammation.
This work was ﬁnancially supported by the Slovenian Research
Agency (Research programme P3-0395: Nutrition and Public
Health). We acknowledge the support of Valens Int. d.o.o.
which supplied the syrups used in this study. The funding
organizations had no role in the design, analysis or writing of
this paper. The authors would like to thank M. Bales for pro-
viding assistance with the language.
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