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Abstract
Niacinamide (also known as nicotinamide,
3-pyridinecarboxamide) is the physiologi-
cally active form of niacin or vitamin B3, the
deficiency of which results in the nutritional
disease pellagra with distinct cutaneous
manifestations. Since its discovery and iso-
lation, a host of dermatological therapeutic
benefits and mechanisms have also been
ascribed to this essential water-soluble vit-
amin when used as a topical agent. These in-
clude its apparent role as an anti-acne ac-
tive, an up-regulator of epidermal sphingo-
lipid synthesis, an up-regulator of markers of
epidermal differentiation and dermal prolif-
eration (with concurrent stratum corneum
barrier benefits), and as a moderator of pho-
toimmunesuppression and accompanying
tumor genesis. More recently, fresh evi-
dence points to a role in modifying the cos-
metic appearance of skin through suppres-
sion of epidermal melanosome transfer with
subsequent effect on skin pigmentation and
a role in modifying epidermal surface topo-
graphy. The mechanisms for these cutane-
ous effects are still unclear. However, since
niacinamide is an important precursor of
NADH and NADPH, it has been postulated
that topical application of niacinamide can
promote this reported broad spectrum of
activity through local correction of homeo-
static balance of these two nucleotide coen-
zymes. As there has been a dramatic in-
crease in research into and use of niacin-
amide in recent years, this review will cover
the current scope of knowledge of this im-
portant vitamin, including mechanistic un-
derstanding and cutaneous physiological
activity.
History of Niacinamide
Niacinamide is the amide of vitamin B3, also
known by the pseudonym »Vitamin PP«, that
is, »Pellagra-Preventive«. The name is not
without meaning. The first case of pellagra
was reported in the U.S. in 1902; four
decades of a pellagra epidemic followed
during which, in states south of the Potomac
and Ohio rivers, some 3 million cases and
100,000 deaths were reported [1]. Pellagra
patients presented with a variety of debili-
tating symptoms including, significantly, a
spectrum of cutaneous lesions. Tragically,
this led to the public exclusion of thousands
of victims, who came almost exclusively
from poor, rural, working-class families who
fed themselves on a bland staple diet of
cornmeal, molasses and fatback. Joseph
Goldberger, a Hungarian emigrant who es-
tablished himself as a renowned clinical epi-
demiologist, reversed steadfast medical
opinion that pellagra was an infectious,
communicable disease. He proved that sim-
ple dietary supplementation could both pre-
vent and cure pellagra. In 1927, after 13 years
of work, Goldberg persuaded the American
Red Cross to distribute dried yeast to Mis-
sissippi flood victims and, thus, prevented a
further devastating epidemic. It was not un-
til 1937 that nicotinic acid and its derivatives
(including niacinamide) were shown to be
the elusive »PP« factor. By 1945, Goldber-
ger’s legacy was permanent; public educa-
tion had changed forever the poor diet of the
South and pellagra was eliminated in the
United States.
Physiological Role of Niacinamide
The substituted pyridine derivative niacin-
amide is an essential constituent of the oxi-
doreduction coenzymes nicotinamide ade-
nine dinucleotide (NAD) and nicotinamide
adenine dinucleotide phosphate (NADP)
(Fig. 2). During glycolysis and the TCA cycle,
10 molecules of NAD+(per molecule of glu-
cose) are reduced to 10 NADH by the trans-
fer of a hydride ion to the 4-position of the
niacinamide ring. The hydride ion of NADH
serves effectively as an energy storage unit,
giving up a pair of high-energy electrons to
the mitochondrial electron transport chain
when needed. In this process of oxidative
phosphorylation, electron pairs are trans-
ferred from NADH to a final acceptor (oxy-
gen) via a series of electron carriers. This
transfer of electrons is thermodynamically
A Review of the Range of Effects of
Niacinamide in Human Skin
Paul J. Matts1), John E. Oblong2) and Donald L. Bissett2)
Keywords: Niacinamide, nicotinamide, skin, ceramide, ageing, differentiation, barrier
IFSCC Magazine – vol. 5, no 4 / 2002
1) The Procter & Gamble Company, Rusham Park Technical Centre, Egham, Surrey, UK
Email: matts.pj@pg.com
2) Miami Valley Laboratories, Cincinnati, Ohio, USA
Fig. 1: Pellagra suffer, US South, early 20th
century
The authors acknowledge the Waring Historical
Library of the Medical University of South Caroli-
na, Charleston, SC
286
favorable, i.e., ∆G is negative, and is coupled
to the pumping of protons out of the mito-
chondrial matrix. The flow of protons back
into the matrix, in turn, catalyses the pro-
duction of ATP by F0F1ATP-synthase. Total
energy yield (∆G’) for this process is high
(–52.7kcal).
Whereas NADH is involved in catabolism,
NADPH tends to serve as an electron (hy-
dride ion) donor in anabolic processes, that
is, biosyntheses. For example, NADPH is the
reducing co-factor used by fatty acid syn-
thetase in lipid biosynthesis and by desmo-
lases and hydroxylases in steroid biosynthe-
sis.
Nicotinamide Coenzymes in Skin
are Depleted with age; Niacin-
amide can Help Normalize this Im-
balance
NADH and NADPH can, thus, be viewed as
fundamental energy »currency« units within
cells, driving the metabolism of cells involv-
ed in both catabolic and anabolic process-
es. There is an increasing pool of evidence
for a decline in systemic and intracellular
concentrations of these two coenzymes
with age in human and animal models [2,3,4]
and recent new data appear to confirm this.
Oblong et al. [5] established human dermal
fibroblast cell lines from a 7-year old and a
72-year old and used these to measure en-
dogenous NADPH/NADP+ratios and total
NADPH + NADP+levels. It was found that
fibroblasts from the aged donor contained
decreased NADP redox ratios and total
NADPH + NADP+levels relative to those
from the young donor (51% and 28% respec-
tively). It does appear, therefore, that there
is a reduction in nicotinamide coenzymes
associated with senescence.
Importantly, Oblong et al. [5] also found that
supplementation of human dermal fibroblast
cultures derived from elderly donors with
14C-niacinamide and 14C-nicotinic acid
(niacinamide precursor) increased intracel-
lular concentrations of NADPH. It appears
that a localized supply of niacinamide, there-
fore, can be utilized by aged cutaneous cells
to restore intracellular nicotinamide coen-
zyme homeostasis.
It is worth noting, however, that despite the
efficacy noted above, nicotinic acid (niacin)
produces a well-documented cutaneous va-
sodilatation (»flushing«) when applied to-
pically. Niacin, therefore, presents a chal-
lenge to cosmetic applications; there are no
such issues with the use of niacinamide.
Aged Fibroblasts Secrete Less
Collagen than Young Cells;
Niacinamide can Stimulate New
Collagen Synthesis
Oblong et al. [5] used 14C-proline to monitor
incorporation of label into collagen protein
secreted from cultured human dermal fibro-
blasts taken from a young (7-year old) and
aged donor (72-year old). 14C-hydroxyproline
(as a marker of newly-synthesized secreted
collagen) and 14C-proline (as a marker of to-
tal protein) were extracted, separated and
quantified using HPLC equipped with a ra-
diometric detector. Results indicated firstly
that dermal fibroblasts from an aged donor
secreted significantly (p<0.05) less collagen
than those from a young donor and, further-
more, that NADPH / NADP redox ratios were
also lower (p<0.05) in fibroblasts from the
aged donor (results were normalized to the
cell number from the respective culture
well). Secondly, it was found that supple-
mentation of the aged cell culture with
niacinamide produced significant increases
in total collagen secreted (by 54%), total pro-
tein secreted (by 41%) and also in the num-
ber of cells (by 20%), relative to a vehicle
control. Importantly, there was also a signif-
icant 35% increase in the collagen / total pro-
tein ratio (relative to a vehicle control), indi-
cating some specificity for collagen biosyn-
thesis and secretion. These data suggest,
therefore, that treatment with niacinamide
would have a positive impact on the dermal
compartment, both in terms of its connective
tissue and gel matrix components. These
effects would be of particular significance in
aged and photodamaged skin.
Niacinamide Up-regulates Epider-
mal Ceramide Synthesis with Con-
current Epidermal Barrier Benefits
Ceramides are now known to play a central
role in the structural and functional integrity
of the stratum corneum barrier function. A
decrease in ceramide fraction has been re-
ported in aged and atopic skin [6]. Tanno et
al. showed that in cultured human epidermal
keratinocytes, niacinamide could induce up
to a 5-fold up-regulation in ceramide syn-
thesis (p<0.05) in a dose-dependent fashion
[7]. Further work by the same group [8]
showed up-regulation of other sphingolipid
fractions (glucosylceramide and sphingo-
myelin) as well as free fatty acid and cho-
lesterol synthesis (by 2.3 and 1.5-fold, re-
spectively). The workers proposed a mech-
anism for these observations based on in-
creased levels of intra-cellular acetyl-CoA
(the precursor common to epidermal lipid
synthesis) and increased expression of ser-
ine-palmitoyltransferase. Tanno et al. [8] al-
so showed that these in-vitro results had
clinical significance in-vivo. Topical applica-
tion of a vehicle containing 2% niacinamide
IFSCC Magazine – vol. 5, no 4 / 2002
Fig. 2: Structure of niacinamide and inclusion within NAD molecule
287
to dry lower legs over 4 weeks induced a
measurable significant increase (p<0.05) in
recovered stratum corneum ceramide and
free fatty acid lipid fractions, vs. a vehicle
control. This was accompanied by a signifi-
cant reduction (p<0.05) in TEWL vs. vehicle
control (–27%). Similar significant reduc-
tions in TEWL vs. a vehicle control were not-
ed also by Ertel et al. [9] after use of a mois-
turizing vehicle containing 2% niacinamide.
Furthermore, they also noted that this posi-
tive barrier effect was accompanied by an
increase in stratum corneum turnover rate
(as measured by dansyl chloride assay). Fi-
nally, Draelos et al. [10] treated 48 female
subjects with stage I/II rosacea with a mois-
turizing vehicle containing 2% niacinamide
for 4 weeks and demonstrated a significant
improvement in global condition (assessed)
in 96% of the subjects at week 4. They de-
monstrated, once again, that this clinical
benefit was accompanied by a significant
improvement in stratum corneum barrier
function.
It appears that topical niacinamide is able to
augment the barrier properties of the skin,
with accompanying clinically relevant ben-
efits, by up-regulating endogenous biosyn-
thesis of epidermal sphingolipids, in partic-
ular, ceramides.
Niacinamide Up-regulates
Biosynthesis of Markers of
Keratinocyte Differentiation
Oblong et al. [5] cultured normal human epi-
dermal keratinocytes to near-confluency
and then supplemented the medium with
niacinamide. Following a 24h incubation,
cells were counted, harvested and prepared
for assay for involucrin (by ELISA) and filag-
grin (by an immunoblot procedure). Results
showed firstly a significant increase (p<0.05)
in the number of niacinamide-treated NHEK
relative to a vehicle control. Secondly, ni-
acinamide-treated NHEK showed an up-
regulation of both involucrin and filaggrin
biosynthesis vs. that induced by a vehicle
control (by 45% and 100% respectively).
These two proteins are both critical to the
differentiation process and the formation of
fully integral keratinized corneocytes; filag-
grin plays a vital role in aggregation and
alignment of keratin tonofilaments in granu-
lar cells and involucrin is an essential pre-
cursor in the formation of the insoluble
cornified envelope surrounding terminal
keratinocytes. In other words, niacinamide
has been shown to both stimulate basal epi-
dermal keratinocytes and to up-regulate
biosynthesis of epidermal intermediates
critical to the formation of a fully functioning
stratum corneum. This may be due to in-
creased intracellular levels of reduced
nicotinamide coenzymes initiated by topical
niacinamide. These effects would be ex-
pected to have a significant positive impact
on ageing epidermal tissue in-vivo.
Niacinamide Helps Prevent
UV-Induced Deleterious Molecu-
lar and Immunological Events
Shen et al. [11] demonstrated the ability of
niacinamide to protect cultured normal hu-
man keratinocytes against reactive oxygen
species induced by UVC irradiation or expo-
sure to hydrogen peroxide. They observed
significant (p<0.05) dose-dependent attenu-
ation of apoptotic morphological changes, a
decrease in p53 induction and a reduction in
DNA ladders for niacinamide-treated cells
vs. those treated with a vehicle control.
These data are consistent with work in ani-
mal models [12] demonstrating clearly the
ability of niacinamide to significantly reduce
both induction of photocarcinogenesis and
photoimmunesuppression. The mechanism
by which niacinamide exerts these effects is
not yet clear.
Niacinamide Inhibits Transfer of
Melanosomes from Melanocytes
to Keratinocytes
Boissy et al. [13] used co-cultures of human
melanocytes and keratinocytes to investi-
gate the ability of niacinamide to reduce pig-
mentation in human skin. Use of immuno-
linked dyes specific for each cell type en-
abled separate counts of keratinocytes,
melanocytes and keratinocytes containing
transferred melanosomes to be performed.
The workers found significant inhibition
(p<0.05) of melanosome transfer to keratino-
cytes from melanocytes incubated in the
presence of niacinamide (by 25-45%). It was
also confirmed that niacinamide had no in-
hibitory effect on melanocyte tyrosinase
activity. These data suggest that treatment
of human skin in-vivo with topical niacin-
amide would lead to a reduction in pigmen-
tation with time via this novel, elegant mech-
anism.
Niacinamide Reduces Human
Skin Hyperpigmentation
Hakozaki et al. [14] performed two studies
demonstrating the effect of niacinamide on
skin hyperpigmentation in-vivo. In the first,
18 female Japanese subjects with hyperpig-
mented facial spots were treated for 8
weeks with a vehicle containing 5% niacin-
amide vs. a vehicle control in a split-face de-
sign. Pigmented spots were qualified and
quantified via algorithmic analysis of high-
resolution digital images and subjective
grading of images. Results of image analysis
showed that 5% niacinamide had induced a
significant (p<0.05) reduction in spot area at
the 4 and 8 week time-points (vs. vehicle
control), accompanied by a significant re-
duction (p<0.05) in graded visible spot pig-
mentation at 8 weeks (vs. vehicle control). In
the second study, 120 female Japanese sub-
jects with facial tanning were assigned to 2
of 3 treatments (SPF 15 sunscreen moistur-
izer, 2% niacinamide in SPF 15 sunscreen
moisturizer and a vehicle control). Subjects
applied treatments split-face for 8 weeks. In
this study overall skin lightness was as-
sessed by analysis of digital images and by
subjective grading. Results of image analy-
sis showed a significant (p<0.05) increase in
skin lightness vs. the sunscreen moisturizer
and vehicle control at the 4 and 6 week time-
points, accompanied by a significant
(p<0.05) increase in graded visible skin light-
ness vs. vehicle control at 4 weeks. These
in-vivo data appear to confirm, therefore,
that the inhibitory role of niacinamide in
melanosome transfer noted in-vitro [13],
does indeed translate to a significant effect
on hyperpigmentation in-vivo.
Regulation of Sebaceous Lipid and
Acne by Niacinamide
Topical niacinamide in the form of a com-
mercial 4% gel (Papulex®) has been shown
to provide potent anti-inflammatory activity
in the treatment of acne vulgaris. Shalita et
al. [15] found that after 8 weeks of usage,
82% of subjects with inflammatory acne
showed an improvement in global evalua-
tion, with a significant reduction in papules /
pustules (–60%) and acne severity (–52%).
Indeed, many practitioners use the treat-
ment citing a combination of efficacy and
lack of bacterial-resistance. Shalita et al.
[15] and others postulate that niacinamide
IFSCC Magazine – vol. 5, no 4 / 2002
288
may act via its apparent antihistaminic ef-
fect, activity as an electron scavenger, or its
inhibition of 3’-5’ cyclic-AMP phosphodi-
esterase activity.
Recent data, however, appear to demon-
strate an altogether more fundamental role
for topical niacinamide in acne treatment.
Biedermann et al. [16] used viable human fa-
cial biopsies (from face-lift surgery) to mea-
sure the effect of niacinamide on sebaceous
lipogenesis. Cultured biopsies were treated
with niacinamide or trans-retinoic acid (tRA)
for 4 days, after which they were incubated
with 14C-acetate. Lipid components were
subsequently isolated, fractionated and
identified using analytical TLC and radiome-
try. Niacinamide produced significant dose-
dependent reductions in total sebaceous
lipogenesis (–42% at 25 mM [p<0.01]). Fur-
thermore, the reduction induced by 25 mM
niacinamide was equivalent to that pro-
duced by 1 µM tRA (–32% [p=0.01]). When
discrete lipid classes were identified and
quantified, it was found that niacinamide
had produced marked reductions in both
triglyceride and fatty acid synthesis vs. the
control (–52% and –46% respectively for 25
mM niacinamide [p<0.05]). It is now known
that triglycerides represent by far the largest
proportion of sebaceous gland lipid (50-
60%); the observed effect of niacinamide on
total lipogenesis is, therefore, probably at-
tributable to triglyceride reduction.
This has important implications for acne
pathogenesis. It is accepted that acne is a
disease involving the pilosebaceous duct
and Propionibacterium acnes. Despite the
on-going debate as to the exact interplay of
these factors, it is without doubt that a sig-
nificant reduction both in total sebaceous
lipid bulk and in the triglyceride fraction
would be expected to impact positively
acne-form skin.
Niacinamide Exerts Multiple
Benefits on the Appearance of
Ageing / Photodamaged Skin,
In-vivo
Bissett et al. [17] studied the effects of topi-
cal niacinamide in ageing human facial skin
in two double-blinded clinical studies. In the
first, 40 female subjects aged 35 - 60 applied
a vehicle and vehicle containing 5% niacin-
amide (randomized split-face) for 12 weeks.
High-resolution digital images were taken at
baseline, 4, 8 and 12 weeks and texture and
hyperpigmentation were evaluated by
judges (comparing blind-coded image pairs,
baseline vs. another treatment time-point).
Judges were able to perceive a significant
improvement in skin texture appearance at
4 weeks (p<0.1) and 12 weeks (p<0.05) and a
significant improvement in hyperpigmented
spot appearance by 8 weeks (p<0.05) (Fig. 3).
In a second study, female subjects aged 35-
60 applied blind-coded products (vehicle
control and vehicle containing 5% niacin-
amide; n=88) split-face for 8 weeks. Skin tex-
ture appearance was assessed as above.
The niacinamide-containing treatment pro-
vided a significant improvement in skin tex-
ture appearance relative to the vehicle con-
trol at the 8 week time-point, confirming the
results of the first study.
This effect on skin surface texture is consis-
tent with that noted in a 10-week clinical
study where Matts & Solechnick [18] used
multiple-angle reflectance spectrophoto-
metry to measure the diffuse component of
skin reflection. They noted a significant in-
crease in the diffuse component of 5%
niacinamide-treated dorsal hand skin vs.
vehicle control after 10 weeks of treatment
(p<0.05), consistent with significant blind
self-rated preferences for texture appear-
ance over vehicle control (p<0.05). This
change was consistent with a shift in texture
distribution towards the finer, anisotropic
features characteristic of younger skin.
Niacinamide is Delivered Effec-
tively from a Range of Vehicles
and Demonstrates Excellent Skin
Compatibility
Franz [19] determined niacinamide absorp-
tion in-vitro through full-thickness abdomi-
nal skin mounted in flow-through diffusion
cells. Franz used acetone as a carrier and
found 28.8% of the starting dose in the re-
ceptor medium at 24 h. Delivery of niacin-
amide (2-20%) from a range of cosmetic for-
mulae (including moisturizers, foundations
and lipsticks) was studied using a modified
in-vitro Franz flow-through cell technique
[20]. For formulae containing 2% niacin-
amide, approximately 10% of the starting
dose was detected in the receptor medium
at 48 h. Importantly, these studies highlight-
ed the apparent independence of niacin-
amide penetration rate from diverse vehicle
matrices.
The Cosmetic Ingredient Review Expert Pan-
el report for niacinamide [21] details a very
wide range of cutaneous tolerance studies
confirming the excellent profile of niacin-
amide as a cosmetic skin care ingredient.
Conclusion
Niacinamide, therefore, has been shown to
be a cosmetic ingredient with an extraordi-
IFSCC Magazine – vol. 5, no 4 / 2002
Baseline 12 Weeks
Fig. 3: Same subject at baseline and after 12 weeks of topical treatment with 5% niacinamide
289
nary breadth and history of cutaneous ben-
efits. It is thought that its fundamental role as
a precursor of reduced nicotinamide coen-
zymes such as NADH and NADPH is pivotal
to its observed effects. It displays distinct
advantages over other ingredients with sim-
ilar benefits, such as retinol, in that it is well
tolerated, and is not subject to oxidation or
photolysis. In short, the multiplicity of effects
and formulation benefits seen with niacin-
amide make it an ideal choice for a variety of
cosmetic products targeting young and old
skin alike.
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IFSCC Magazine – vol. 5, no 4 / 2002