The fundamental role of hormones in the development of acne cannot
be ignored. Most of the androgens such as dihydrotestosterone
(DHT) and testosterone, adrenal precursor dehydroepiandrosterone
sulfate and estrogens are produced by the gonads and adrenal glands.
Conditions of androgen excess or hyperandrogenism are associated
with increased sebum production which in turn leads to acne formation.
Thus, to counter this problem of excessive androgen, hormonal
therapy that includes the use of anti androgens is recommended.
The role of androgens
That androgens are essential in the development of severe types
of acne is explained by the fact that the onset of prepubertal
as well as acne in women, which do not respond to traditional
therapies, is associated with high levels of serum androgen levels.
Many biological processes are involved in the pathogenesis of
acne and androgens play a key role and stimulate sebum production.
However, it is still not proved whether serum androgen, locally
produced androgens or a combination of both are responsible for
Anti androgens in hormonal therapy for women
Hormonal therapy is ideal for women with proven ovarian or adrenal
hyperandrogenism, hirsutism, excessive sebum secretion and acne
beginning in adulthood and worsening before periods, and acne
which are severe and resistant to other forms of treatment. Hormonal
therapy for acne involves using anti androgens or androgen receptor
blockers as well as agents that inhibit androgen production from
the ovary or the adrenal glands. Androgen receptor blockers like
cyprotene acetate, spironolactone, flutamide and finesteride are
used for severe acne associated with high levels of serum androgens.
Anti androgens block the effect of androgens on the sebaceous
DHT is the effector androgen that mediates sebum production.
Dihydrotestosterone is approximately 5-10 times stronger than
testosterone in its reaction with the functional androgen receptor
which leads to acne production. This dihydrotestosterone is produced
from testosterone within the peripheral tissues such as the skin
by the action of 5 alpha-reductase enzyme. The activity of 5-alpha-reductase
in sebaceous glands in skin is prone to acne especially in the
facial area. It is greater than that in sebaceous glands in non-acne
prone skin. This implies that due to this enzyme there is increased
production of powerful androgens such as DHT within the sebaceous
glands of the facial area which in a way points towards the development
of acne in these particular areas.
Two isozymes of 5 alpha – reductase are identified. The
type 1 is active within the sebaceous glands whereas the type
2 isozyme is most active in the prostrate gland in men. Finasteride
is a specific inhibitor of the 5 alpha-reductase 2 enzyme, the
enhanced activity of which leads to the development of androsterone
and ultimately to the formation of severe acne in adult women.
Hyperandrogenic women suffering form acne are sometimes treated
with finasteride – though more so in Europe than in North
Finesteride has shown to be similar in effectiveness to other
well-established anti-androgen treatments in hyperandrogenic acne.
Moreover, only a very low dosage of 5 mg per day of this anti
androgen receptor blocker is effective in acne reduction. In patients
who respond well to treatment, acne improves rapidly and may even
be thoroughly eliminated after two to three months.
Finasteride compared to other anti androgens
Finasteride is reported to successfully reduce acne lesions but
total acne scores are reduced by approximately 36%, which is lower
compared to another novel anti androgen flutamide. Even low doses
of flutamide at 250 mg daily are observed to be as effective as
cyproterone acetate in acne reduction and reduced acne scores
by 60% in majority of patients. This may be explained by the fact
that finasteride inhibits the 5 alpha-reductase 2 enzyme while
acne development is associated mainly with 5alpha-reductase 1
Associated side effects
Despite its lower effectiveness compared to other anti-androgen
drugs, finasteride is still used to treat androgenic acne. The
risk of side effects from finasteride is much lower compared to
flutamide, which is rarely used because of its significant side
effect profile. Finasteride side effect risks are also somewhat
lower than cyproterone acetate.
Finasteride is well tolerated. No side effects are observed with
the dosage of 5 mg finasteride used daily. Finasteride does not
have any effect on the pattern of menstrual flow and neither does
it affect the blood glucose level or liver enzymes of women treated
with this drug.
However, since finasteride is an anti androgen, women who are
using this drug but wish to get pregnant should stop using the
drug. Getting pregnant when using finasteride will result in
significant developmental defects in the embryo. When women
of child bearing age are given finasteride by dermatologists,
they are also required to use oral contraceptives to prevent
So all said and done, finasteride though less beneficial or effective
compared to the antiandrogen flutamide is still an effective androgen
receptor blocker and is successful in treating severe androgenic
acne even at a lower dosage of 5 mg per day.