Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study Group.
BACKGROUND
Androgenetic alopecia (male pattern hair loss) is caused by androgen-dependent miniaturization of scalp hair follicles, with scalp dihydrotestosterone (DHT) implicated as a contributing cause. Finasteride, an inhibitor of type II 5alpha-reductase, decreases serum and scalp DHT by inhibiting conversion of testosterone to DHT.


OBJECTIVE
Our purpose was to determine whether finasteride treatment leads to clinical improvement in men with male pattern hair loss.


METHODS
In two 1-year trials, 1553 men (18 to 41 years of age) with male pattern hair loss received oral finasteride 1 mg/d or placebo, and 1215 men continued in blinded extension studies for a second year. Efficacy was evaluated by scalp hair counts, patient and investigator assessments, and review of photographs by an expert panel.


RESULTS
Finasteride treatment improved scalp hair by all evaluation techniques at 1 and 2 years (P < .001 vs placebo, all comparisons). Clinically significant increases in hair count (baseline = 876 hairs), measured in a 1-inch diameter circular area (5.1 cm2) of balding vertex scalp, were observed with finasteride treatment (107 and 138 hairs vs placebo at 1 and 2 years, respectively; P < .001). Treatment with placebo resulted in progressive hair loss. Patients' self-assessment demonstrated that finasteride treatment slowed hair loss, increased hair growth, and improved appearance of hair. These improvements were corroborated by investigator assessments and assessments of photographs. Adverse effects were minimal.


CONCLUSIONS
In men with male pattern hair loss, finasteride 1 mg/d slowed the progression of hair loss and increased hair growth in clinical trials over 2 years.
Department of Clinical Research, Merck Research Laboratories, Rahway, NJ 07065, USA.
K D
KD
Kaufman
E A
EA
Olsen
D
D
Whiting
R
R
Savin
R
R
DeVillez
W
W
Bergfeld
V H
VH
Price
D
D
Van Neste
J L
JL
Roberts
M
M
Hordinsky
J
J
Shapiro
B
B
Binkowitz
G J
GJ
Gormley
D000328:Adult; D000505:Alopecia / Q000097:blood / Q000188:drug therapy*; D002170:Canada; D013196:Dihydrotestosterone / Q000097:blood; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D018120:Finasteride / Q000009:adverse effects / Q000627:therapeutic use*; D006197:Hair / Q000187:drug effects; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014481:United States
D004791:Enzyme Inhibitors; D013196:Dihydrotestosterone; D018120:Finasteride