finasteride in androgenetic alopecia

Last reviewed 01/2018

• launched as a treatment for androgenetic alopecia (male-pattern baldness) in males in March 2002 in the UK
• finasteride is a potent inhibitor of type II 5-alpha reductase (this enzyme is responsible for conversion of testosterone to dihydrotestosterone (DHT)). Men with a genetic deficiency of type II 5-alpha reductase do not develop androgenetic alopecia
• various multi-centre trials have demonstrated the preservative and restorative effects of finasteride in males with androgenetic alopecia (1,2)
  • there is trial evidence that after a two-year period of treatment 66% of patients demonstrated increased hair coverage (compared to 7% receiving placebo); also a further 33% experienced no further loss when assessed by global scalp photography
  • assessing using hair counts revealed 83% of patients receiving finasteride improved or maintained compared with 28% on placebo
  • only adverse effects reported in more than 1% of patients were erectile dysfunction and loss of libido - these were reversible with discontinuation of therapy
• finasteride is contraindicated in women because of the risk in pregnancy of using this drug

An increased risk of breast cancer in finasteride users have been reported in clinical trials (3).

The summary of product characteristics should be consulted before using this drug.

• (1) Whiting DA. Advances in the treatment of male alopecia: a brief review of finasteride studies. Eur J Dermatol 2001;11:332-4.
• (2) Kaufman KD et al.Finasteride in the treatment of men with androgenetic alopecia. J Am Acad Dermatol 1998;39:578-89.
• (3) Medicines and Healthcare products Regulatory Agency (MHRA). Finasteride: potential risk of male breast cancer. Drug Safety Update 2009;3(5)