Benzoyl peroxide has been, for quite some time now, one of the
most important and well-known drug formulations available for
topical acne treatment. It has very useful properties, such as
strong anti microbial action and slight anti-inflammatory and
anticomedogenic effects making it a very effective anti-acne agent.
It is an excellent first choice medication and the initial response
to treatment is obtained in as early as five days.
Treatment with benzoyl peroxide alone
In fact, treatment with benzoyl peroxide alone significantly
improves inflammatory acne. Side effects encountered are common
irritant dermatitis with erythema, scaling and itching. These
side effects can, however, be avoided or lessened by less frequent
application of benzoyl peroxide. The incidence of true contact
sensitivity is low. Very rarely, it produces photosensitivity.
It is known that water-based benzoyl peroxide preparations with
concentrations between 2.5% to 5% are found to cause significantly
less skin irritation than preparations based on alcohol, with
no loss in efficacy. A disadvantage, rather than side effect,
that a user needs to be aware of is that benzoyl peroxide can
bleach clothing and bedding.
A study was conducted recently to compare the effectiveness of
2.5%, 5% and 10% formulations of gel benzoyl peroxide. It was
found that the 2.5% formulation was as effective and less drying
as the two other formulations in reducing inflammatory lesions
and significantly reduced acne after two weeks of topical application.
Local side effects were less frequent with the 2.5% and 5% formulations
than with the 10% gel.
Benzoyl peroxide in combination therapy
The use of benzoyl peroxide in combination therapy started with
the dramatic increase of bacterial resistance to antibiotics among
patients with acne. Treatment with antibiotics rapidly induces
bacterial resistance and decreases the efficacy of these drugs.
Benzoyl peroxide protects against such developments. Currently,
the use of combination therapy, such as the addition of benzoyl
peroxide to a topical drug to reduce bacterial resistance, has
Combination therapy of benzoyl peroxide and topical antibiotics
has been shown to be more effective and better tolerated than
with benzoyl peroxide alone. This might be correlated to leukocyte
antioxidant enzyme activity. In one study it was seen that after
4 weeks of twice daily treatment with benzoyl peroxide 5% gel
alone, no changes were observed, whereas the combination of erythromycin
3% and benzoyl peroxide 5% led to reduced antioxidant enzyme activities
in the leukocytes of acne spots.
According to most recent reports, antibiotic resistance is becoming
an increasing problem. The resistance is found more often in the
case of erythromycin and clindamycin as compared with tetracyclines,
although resistance is seen against all of the antibiotics in
general use for acne. The resistance strains that could be isolated
from physicians and casual contacts of acne patients treated with
antibiotics indicated the urgent need to develop ways and means
to combat the spread of and reduce antibiotic resistance. It is
therefore important that benzoyl peroxide, which both reduces
the still existing antibiotic resistant populations and decreases
the emergence of new resistant populations, should be used where
In combination therapy, despite its high effectiveness as an
anticomedogenic, antimicrobial and antibacterial agent, benzoyl
peroxide is limited by its side effects of dryness and irritation
mentioned above. Combination therapy with once daily tretinoin
0.1% microsphere gel and benzoyl peroxide 6% cleanser was shown
to be more effective in reducing inflammatory but not non-inflammatory
lesions in comparison with tretinoin 0.1% microsphere alone at
12 weeks, without an accompanying increase in local skin irritation.
Recently, new premixed formulations of benzoyl peroxide and topical
antibiotics have been introduced. These newer formulations are
stable at room temperature and more convenient for patients than
older preparations, which required refrigeration. The premixed
combination products include erythromycin 3% and benzoyl peroxide
5% or clindamycin 1% and benzoyl peroxide 5%. Clindamycin 1% with
benzoyl peroxide 5% topical products used once daily have been
shown to be effective in reducing inflammatory and noninflammatory
lesions by 53% and 25% respectively for patients with moderate
or moderately severe acne after 11 weeks of treatment. Patients
generally tolerated these preparations well.
Overall then, benzoyl peroxide is an acne treatment that is well
worth considering either on its own or in combination with other