Clinical Trial of Bleaching Treatment With 10%
All-Trans Retinol Gel
K OTARO Y OSHIMURA , MD, n A KIRA M OMOSAWA , MD, n E MIKO A IBA , MD, n K ATSUJIRO S ATO ,MD, n D AISUKE M ATSUMOTO , MD, n Y OKO M ITOMA , MD, n K IYONORI H ARII , MD, n
TAKAO A OYAMA , P H D, w AND TATSUJI I GA , P H D w
Department of Plastic and Reconstructive Surgery, and wDepartment of Pharmacy, University of Tokyo, Graduate
School of Medicine, Tokyo, JapannBACKGROUND. Although an aggressive use of tretinoin alongwith hydroquinone enables an efficient treatment of hyperpigmented skin lesions, irritant dermatitis remains to be solved.
OBJECTIVE. To evaluate the efficiency and adverse effects of
10% all-trans retinol (ROL) gel for improvement of skinhyperpigmentation.
METHODS. Ten-percent ROL gel was used instead of 0.1%
tretinoin gel in our two-phased bleaching protocol (bleaching
and healing phases); 5% hydroquinone and 7% lactic acidointment were used along with ROL gel in the bleaching phase(2 to 6 weeks). Five-percent hydroquinone and 7% ascorbic
acid ointment were used alone during the healing phase (4 to 6

weeks). Twenty-one Japanese patients with hyperpigmented
lesions on the face were enrolled in this study, and 18 patients
who were followed for more than 10 weeks were analyzed.
RESULTS. Improvement of pigmentation was seen in 16 of 18
patients after an average treatment period of 11.3 weeks, and in
6 patients, pigmentation was almost eliminated after treatment.
Erythema and scaling were seen, however, during the bleachingphase as well as the bleaching treatment with tretinoin gel.
CONCLUSION. ROL can improve skin hyperpigmentation to asimilar extent to tretinoin when used at high concentration,
whereas it induces irritant dermatitis as well.

K. YOSHIMURA, MD, A. MOMOSAWA, MD, E. AIBA, MD, K. SATO, MD, D. MATSUMOTO, MD, Y. MITOMA, MD,
K. HARII, MD, T. AOYAMA, PhD, AND T. IGA, PhD HAVE INDICATED NO SIGNIFICANT INTEREST WITHCOMMERCIAL SUPPORTERS.

TRETINOIN AND hydroquinone have been usedsuccessfully for treatment of skin hyperpigmentation
since Kligman and Willis1 introduced their bleaching
formula. Several modified protocols have been reported,2 and the authors also proposed an aggressive
bleaching therapy, in which tretinoin and hydroquinone were used separately and corticosteroids were
not used.3–6 In our facility, more than 8,500 cases withvarious kinds of hyperpigmented lesions have beensuccessfully treated with our protocol and its modifications since 1995. Virtually the only adverse side
effect of the strong bleaching treatment is irritantdermatitis. Further investigations and clinical trials
would be worthwhile in order to reduce the displeasing side effects without losing bleaching ability.
All-trans retinol (ROL) and all-trans retinal (RAL)
have been considered to be less irritating than tretinoin
if applied at relatively low (0.1% to 1.6%) concentraAddress correspondence and requests for reprints to: Kotaro Yoshimura, MD, Department of Plastic and Reconstructive Surgery, Graduate
School of Medicine, University of Tokyo, 7–3–1, Hongo, Bunkyo-Ku,
Tokyo 113–8655, Japan, or e-mail: yoshimura-pla@h.u-tokyo.ac.jp.

tion.7,8 However, because binding affinity to specificnuclear receptors (retinoic acid receptors; RARs) of
ROL or RAL is far less than that of tretinoin,
beneficial effects are also expected to be very moderatecompared with tretinoin. Our previous study revealed
that heparin-binding epidermal growth factor-likegrowth factor (HB-EGF) mRNA, which plays a criticalrole in epidermal growth after retinoid treatment,9,10
was upregulated by ROL or RAL to a similar extent as
tretinoin, but only when ROL or RAL was used at 40
to 100 times higher concentration than tretinoin.11
Because proliferation of keratinocytes and accelerationof epidermal turnover appear to be the two main
mechanisms of accelerated melanin discharge by
retinoids,11,12 we consider that promotion of HBEGF mRNA expression may be used as an important
index to evaluate the depigmenting ability of topicalretinoids.
Based on the data mentioned previously here, we
prepared 10% ROL aqueous gel because ROL gel of
100 times higher concentration than tretinoin can be
expected to show similar clinical effects to tretinoin gel(0.1%). In this trial study, the ROL gel was clinicallyr 2003 by the American Society for Dermatologic Surgery, Inc.  Published by Blackwell Publishing, Inc.
ISSN: 1076-0512/02/$15.00/0  Dermatol Surg 2003;29:155–160

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used for depigmenting in order to estimate its
bleaching potential and the extent of adverse side
effects.

Methods

Preparation of Ointments
ROL aqueous gel (10%) was originally prepared andpacked into small stainless tubes (5 g each) at the
Department of Pharmacy, University of Tokyo Graduate School of Medicine. The precise regimen of ROL
aqueous gel for 100 g was as follows: all-trans ROL 10
g (Sigma Chemical, St. Louis, MO), Carbopol 940 1 g(Goodrich Chemical, Hounlow, UK), polyoxyethylene
oleyl ether 2.5 g (Kao, Tokyo, Japan), methyl phydroxybenzoate 0.026 g (Wako Pure Chemical
Industries, Osaka, Japan), propyl p-hydroxybenzoate
0.014 g (Wako Pure Chemical Industries), 10%
sodium hydroxide aqueous solution 0.6 mL, andpurified water 86 g. An ointment including 5%hydroquinone and 7% lactic acid (HQ-LA ointment)
and an ointment including 5% hydroquinone and 7%
ascorbic acid (HQ-AA ointment) were also prepared.
Plastibase (petrolatum polyethylene ointment base;Taisho Pharmacology, Osaka, Japan) was used as theointment base of the HQ-LA ointment, whereas thehydrophilic ointment was used for the HQ-AA
ointments. Because ROL gel, HQ-LA, and HQ-AA
ointments (especially ROL gel) are pharmacologicallyunstable, fresh ointments were prepared at least once amonth and stored in a dark and cool (41C) place.

Evaluations of Results
Photographs were taken for every patient at baseline
and after treatment with a high-resolution digital
camera (Canon EOS-D30). The percentage of pigmentary clearance was evaluated via the photographs by
two experienced plastic surgeons who did not perform
this treatment. The mean data of the pigmentary
clearance of each patient were classified into four
categories: excellent (90% or more clearance), good
(60% to less than 90% clearance), fair (30% to lessthan 60% clearance), and poor (less than 30%
clearance).

Patients
Each ointment was topically applied under signed
informed consent in 21 Japanese women with hyperpigmented skin lesions on the face, and 18 of themfollowed for more than 10 weeks were analyzed in thisstudy. The other three patients stopped treatment
because of irritant dermatitis induced by ROL gel and/Dermatol Surg 29:2:February 2003

or hydroquinone. The age of patients ranged from 20
to 67 years old (age, 43.277.0; mean 7SD). Thirteen
patients had solar lentigines. Five had melasma, andfour had ephelides. Four patients had two kinds ofpigmented lesions.

Treatment Protocol
Our bleaching protocol is composed of two phases, ableaching phase and a healing phase. In the bleachingphase, the pigmentation is aggressively treated, andtransient adverse skin effects such as erythema andirritation are usually observed. Once satisfactory
improvement is obtained, the healing phase is started
in order to reduce the erythema and inflammation,
taking care not to induce new postinflammatory
hyperpigmentation.
1. Bleaching phase: 10% ROL gel and HQ-LA
ointment were applied twice a day. ROL gel was
carefully applied only on pigmented areas using asmall cotton-tip applicator, and subsequently,
HQ-LA ointment was widely applied with theﬁngers beyond the pigmented area (e.g., all overthe face). Patients were requested to visit our
hospital at 1, 2, 4, 6, and 8 weeks after starting thistreatment and every 2 weeks thereafter. In mostcases, it took 2 to 6 weeks to ﬁnish this phase.
2. Healing phase: After sufﬁcient improvement ofpigmentation was obtained, the application of
ROL gel and HQ-LA ointment was discontinued,
and application of HQ-AA ointment all over theface was started. HQ-AA ointment was used until
the erythema was almost eliminated, and it took 4
to 6 weeks to complete this phase. Topicalcorticosteroids were not employed either in thebleaching or healing phase.

Results
The average treatment period of 18 patients was 11.3
weeks and ranged from 8 to 16 weeks. Erythema andscaling appeared during the first week in most cases.
Compared with thousands of our cases treated with
0.1% tretinoin gel (our preparation regimen is available in Yoshimura et al.4), we thought that 10% ROL
gel induced a slightly less degree of erythema and ahigher degree of scaling in the first 2 weeks, althoughstatistical analysis was not performed. In addition,
tolerance to the active reagent seemed to be acquired
earlier in the ROL treatment than with tretinoin. In
patients who achieved tolerance as early as 2 weeks,further improvement was deemed unlikely, and thus,
the results were categorized as poor and fair.

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157

Table 1. Summarized Data of Objective Evaluations
Excellent
Good
Fair
Poor
Total

6 (33.3 %)
7 (38.9 %)3 (16.7 %)2 (11.1 %)
18 (100 %)The clinical results were summarized in Table 1. Six
patients (33.3%) were evaluated as ‘‘excellent,’’ sevencases (38.9%) as ‘‘good,’’ three cases (16.7%) as ‘‘fair,’’
and two cases (11.1%) as ‘‘poor.’’ Some improvement
was seen in 16 of 18 patients (88.9%). Most of fairand poor cases had very mild or no skin reactions
such as scaling and erythema during the bleachingphase. The representative four cases are shown in
Figures 1–4.

Discussion
In bleaching treatment with tretinoin and hydroquinone, we believe that the role of tretinoin is to washmelanin granules out of epidermis, whereas that ofhydroquinone is to suppress strongly new melanin
production.11,12 Tretinoin induces exfoliation, andthus, it appears to also act as a penetration enhancerof hydroquinone. However, tretinoin has a specificeffect as a discharger of epidermal melanin that cannot
be performed by other penetration-enhancing procedures such as alpha hydroxyacid peeling and microdermabrasion. These exfoliating procedures simply
induce the subsequent normal wound healing process
and discharge epidermal melanin only very weakly. On
the other hand, it is suggested that tretinoin promotes
discharge of melanin granules in epidermis by (1)accelerating epidermal turnover (differentiation of
keratinocytes) in a direct manner and also (2)promoting epidermal growth (proliferation of keratinocytes) in an indirect manner; the latter of the two
effects was found to be mediated by HB-EGF secreted
by suprabasal keratinocytes.9,10,13 Indeed, the successful results of an aggressive bleaching treatment withtretinoin and hydroquinone cannot be obtained by
combination therapies of other exfoliating procedures
and topical hydroquinone.4 These observations suggest a specific ability of retinoids as a melanindischarger.
As mentioned previously here, the mechanism of
this bleaching therapy seems to be very simple:
Tretinoin accelerates the loss of epidermis melanin,whereas hydroquinone suppresses the production. The
bleaching therapy with tretinoin appears to be only
effective for epidermal pigmentation because we

Figure 1. Case 1. A 46-year-old woman with a solar lentigine andmelasma on her cheek underwent the treatment (A, before
treatment); 10% ROL gel was used for 4 weeks together with HQLA ointment (B, at 4 weeks; after bleaching treatment), followed byapplication of HQ-AA ointment alone for 4 weeks. Both the solar
lentigine and melasma almost disappeared after 8 weeks of treatment(C, at 8 weeks).

confirmed histologically that accumulated melanin
granules around the basal layer were cleared up after
treatment with tretinoin and hydroquinone, but the158

YOSHIMURA ET AL.: BLEACHING TREATMENT WITH 10% ROL GEL

Dermatol Surg 29:2:February 2003

Figure 2. Case 2. A 54-year-old woman with several solar lentigines on
her right cheek underwent the treatment (A, before treatment); 10%
ROL gel was used for 2 weeks together with HQ-LA ointment,
followed by application of HQ-AA ointment alone for 6 weeks.
Significant erythema and irritation on the treated area were observed
1–3 weeks after starting the treatment (B, at 2 weeks; after bleachingphase). The erythema almost disappeared after 6-week healing phase,
although slight postinflammatory hyperpigmentation was left on thetreated areas (C, at 8 weeks).

melanin deposits in the dermis appeared not to changein acquired bilateral nevus of Ota-like macules, which
has both epidermal and dermal pigmentation (inpreparation).
The authors recently reported that ROL and RAL
can markedly induce HB-EGF mRNA upregulation ata pharmacologic concentration (0.01 to 1 mmol/L) in
cultured human keratinocytes.11 However, in cases of
ROL and RAL, 40 to 100 times higher concentration
was required in order to upregulate HB-EGF mRNA toa similar extent to tretinoin.11 In this study, we
prepared and used 10% ROL gel, which is 100 times
higher concentration that 0.1% tretinoin gel because it
could be expected to clinically induce HB-EGF
expression in the epidermis as well as topical 0.1%

Figure 3. Case 3. A 32-year-old woman with melasma and some solar
lentigines underwent the treatment (A, before treatment); 10% ROL
gel was used for 4 weeks combined with HQ-LA ointment, followed bysingle application of HQ-AA ointment for 4 weeks. Irritant dermatitis
was seen on the treated areas throughout the bleaching phase, butpigmentation was improved significantly by day 28 (B, at 4 weeks;
after bleaching phase). After 4 weeks of healing phase, erythemadisappeared without leaving postinflammatory hyperpigmentation (C,at 8 weeks).

tretinoin. The results suggest that 10% ROL gel wascomparable in effectiveness to 0.1% tretinoin gel in
improving skin hyperpigmentation compared with ourbleaching experience with thousands of patientstreated with 0.1% tretinoin gel.
ROL and RAL are considered to work predominantly after conversion to tretinoin. The binding
affinities of ROL and RAL to RARs are quite low14

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Figure 4. Case 4. A 34-year-old woman with ephelides underwent thetreatment (A, before treatment). Bleaching was performed with 10%
ROL gel and HQ-LA ointment for 4 weeks; thereafter, HQ-AA ointment
alone was used for 6 weeks. The pigmented spots were almost
eliminated, and mild rosy glow was still seen at 10 weeks (B, at 10
weeks).

so that their biologic activity should result from theiroxidative transformation into tretinoin by epidermal
keratinocytes. This conversion to tretinoin after
topical application of ROL and RAL was revealed tooccur in a study using skin organ culture,15 although
the conversion rate has not been clearly measured sofar. However, there have been some reports suggesting
the existence of other pathways than that mediated by
nuclear receptors.16 Thus, ROL seems to show its
biologic activity through direct binding to RARs,
transformation into tretinoin, and other pathways.
HB-EGF mRNA upregulation in suprabasal keratinocytes can be expected to occur in vivo after topicalapplication of ROL.
ROL is known to show far less severe side effects(such as irritation) than tretinoin, at least when used atsimilar concentration, and thus has been thought to be
more tolerable and may be of great value in clinicaluse. However, this study revealed that even ROL can
induce irritant contact dermatitis to a similar extent as

159

tretinoin when used at a 100-times higher concentration, although it also showed beneficial effects similar
to tretinoin. Retinyl esters such as retinyl palmitate
and retinyl acetate are pharmacologically very stable,
and topical formulations of them are widely available
mainly as cosmetics. Although retinyl esters are known
to show even less irritation than ROL, their biologic
activity as retinoids appears to be far less than that ofpure ROL or RAL17 and cannot be expected to beeffectively transformed to retinoic acids and to workas drugs.
It remains unknown what percentages of ROL in
the prepared ROL gel were absorbed into the skin.
Unlike the 0.1% tretinoin gel we used in which morethan 96% of the gel is composed of water, the 10%
ROL gel contains 10% ROL, whereas water formed
only 86% of it. The permeability of ROL in the 10%
ROL gel may be much less than that of tretinoin in the
0.1% tretinoin gel. Therefore, 5% ROL gel, whichshould contain more water, may show similar depigmenting effects to the 10% ROL gel.
In this study, we showed that ROL can play adepigmenting role as well as tretinoin. However, thecost performance of the ROL gel is very poor
compared with the tretinoin gel, as far as our
preparations are concerned. Purified ROL is commercially available, but 1 g costs almost the same as 1 g oftretinoin. Because 100 times the amount of theworking ingredient was required to prepare the ROL
gel, it costs 100 times more. In light of this, it seems to
be impractical to use clinically the 10% ROL gel that
we prepared.

Conclusions
This clinical trial revealed that 10% ROL gel clinicallyshow a considerable bleaching effect, which seems tobe as good as that of 0.1% tretinoin gel, but the ROL
gel also induced adverse side effects, such as irritantdermatitis, to a similar degree as tretinoin gel.

References
1. Kligman AM, Willis I. A new formula for depigmenting humanskin. Arch Dermatol 1975;111:40–8.
2. Gano SE, Garcia RL. Topical tretinoin, hydroquinone, andbetamethasone valerate in the therapy of melasma. Cutis
1979;23:239–41.
3. Yoshimura K, Harii K, Shibuya F, et al A new bleaching protocol
for hyperpigmented skin lesions with a high concentration of alltrans retinoic acid aqueous gel. Aesthetic Plast Surg 1999;23:285–91.
4. Yoshimura K, Harii K, Aoyama T, Iga T. Experience of a strong
bleaching treatment for skin hyperpigmentation in Orientals. Plast
Reconstr Surg 2000;105:1097–108.
5. Yoshimura K, Harii K, Masuda Y, et al. Usefulness of a narrowband reflectance spectrophotometer in evaluating effects ofdepigmenting treatment. Aesthetic Plast Surg 2001;25:129–33.

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6. Yoshimura K, Momosawa A, Watanabe A, et al. Color improvement of the nipple-areola complex by optimal use of tretinoin andhydroquinone. Dermatol Surg, in press.
7. Kang S, Duell EA, Fisher GJ, et al. Application of retinol to humanskin in vivo induces epidermal hyperplasia and cellular retinoid
binding proteins characteristic of retinoic acid but without
measurable retinoic acid levels or irritation. J Invest Dermatol
1995;105:549–56.
8. Fluhr JW, Vienne MP, Lauze C, et al Tolerance profile of retinol,
retinaldehyde and retinoic acid under maximized and long-termclinical conditions. Dermatology 1999;199(Suppl 1):57–60.
9. Xiao JH, Feng X, Di W, et al Identification of heparin-binding EGFlike growth factor as a target in intercellular regulation of
epidermal basal cell growth by suprabasal retinoic acid receptors.
EMBO J 1999;18:1539–48.
10. Varani J, Zeigler M, Dame MK, et al. Heparin-binding epidermalgrowth-factor-like growth factor activation of keratinocytes ErbB
receptors mediates epidermal hyperplasia, a prominent side-effectof retinoid therapy. J Invest Dermatol 2001;117:1335–41.
11. Yoshimura K, Uchida G, Okazaki M, et al. Differential expressionof heparin-binding EGF-like growth factor (HB-EGF) mRNA in
normal human keratinocytes induced by a variety of natural andsynthetic retinoids. Exp Dermatol, in press.

12. Yoshimura K, Tsukamoto K, Okazaki M, et al Effects of all-transretinoic acid on melanogenesis in pigmented skin equivalents andmonolayer culture of melanocytes. J Dermatol Sci 2001;27(Suppl1):68–75.
13. Stoll SW, Elder JT. Retinoid regulation of heparin-binding EGF-likegrowth factor gene expression in human keratinocytes and skin.
Exp Dermatol 1998;7:391–7.
14. Crettaz M, Baron A, Siegenthaler G, Hunziker W. Ligand
specificities of recombinant retinoic acid receptors RA alpha andRAR beta. Biochem J 1990;272:391–7.
15. Bailly J, Crettaz M, Schifflers MH, Marty JP. In vitro metabolism byhuman skin and fibroblasts of retinol, retinal and retinoic acid. Exp
Dermatol 1998;7:27–34.
16. Saurat JH, Sorg O, Didierjean L. New concepts for delivery of
topical retinoid activity to human skin. In: Nau H, Blaner WS, eds.
Retinoids. Berlin: Springer, 1999:521–38.
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Acad Dermatol 1998;39:S2–7.

Commentary

to another. For example, the retinyl esters can be converted to
ROL via hydrolysis. ROL can be converted to retinaldehyde via
oxidation, and another oxidation step can convert retinaldehyde to retinoic acid. This is particularly important when one
realizes that the enzymatic machinery to perform the conversions resides within the skin. Current research is aimed atdetermining how much conversion can realistically occur. It is
unknown how much ROL can be converted to retinoic acidover what period of time. The interest has been in quantitating
how much ROL, an over-the-counter vitamin, is converted toretinoic acid, a prescription product. The chemistry becomesquite interesting because it blurs the current distinction between
a vitamin, a cosmetic active, and a prescription medication.
This article investigates the effect of ROL in lightening skin, acommon worldwide problem especially in women of color.
ROL is present in some over-the-counter skin lightening andcosmeceutical preparations usually in concentrations of 2% orless, because of tremendous irritation induced by this active.
This research that uses 10% all-trans ROL gel is particularly
notable for the irritation sustained by the patients. Combining
the ROL with lactic acid, a penetration enhancer, furthers thepenetration of ROL into the skin, but also enhances theirritation. These researchers had to prepare the study
ROL formulation monthly because of instability. Thus,
ROL products may eventually augment those hydroquinonebased skin lightening products currently used in the UnitedStates, once the irritation and stability issues are resolved.

Retinoid research began the entire cosmeceutical era when it
was proven that tretinoin could actually regenerate collagen,improve dyspigmentation, and enhance skin texture. This bodyof research that began in the 1960s is continuing as retinoid
technology is being refined in the pharmaceutical market andadapted to the over-the-counter market. This article deals withthe use of an extemporaneously compounded 10% all-trans
ROL gel. Retinoids are basically yellow, fat-soluble, lipophiliccompounds that are sensitive to light, oxygen, and heat. They
chemically conform to an aromatic ring structure with a carbon
chain and terminal group that can be varied to determine thefunction, stability, and irritation profile of a retinoid on theskin. It is research into this terminal group that is the current
focus of retinoid research. ROL, the active used in this study, isa naturally occurring form of vitamin A, whereas retinoic acid(tretinoin) and retinaldehyde are vitamin A metabolites. Retinyl
acetate, retinyl propionate, and retinyl palmitate are vitamin A
esters currently used in the over-the-counter market. Thesevarious retinoids have different formulations issues anddifferent skin effects. Retinyl esters are popular in cosmetics,
as they are less sensitive to oxidation, thus demonstrating
greater stability and a longer shelf life, and are the least
irritating to the skin. On the other hand, retinoic acid isrelegated to the prescription market due to its current
classification as a drug and its high skin irritation profile.
ROL, the subject of this article, is less irritating than retinoic
acid but is highly unstable. The most interesting aspect of thesevitamin A metabolites is the theoretical interconversion of one

ZOE DIANA DRAELOS, MD
High Point, NC