From the FDA Drug Label
The development and enlargement of the prostate gland is dependent on the potent androgen, 5α -dihydrotestosterone (DHT). Type II 5α-reductase metabolizes testosterone to DHT in the prostate gland, liver and skin. DHT induces androgenic effects by binding to androgen receptors in the cell nuclei of these organs Finasteride is a competitive and specific inhibitor of Type II 5α-reductase with which it slowly forms a stable enzyme complex.
The FDA drug label does not answer the question.
From the Research
Oral finasteride may be considered as a treatment option for women with androgenetic alopecia, particularly in postmenopausal women or those who cannot become pregnant, at a dose of 5 mg per day, as suggested by the most recent and highest quality study 1. When considering treatment options for women with androgenetic alopecia, it is essential to weigh the potential benefits and risks of each therapy.
- The use of oral finasteride in women is generally considered off-label, and its effectiveness and safety have been less extensively studied compared to its use in men.
- However, a systematic review of clinical trials using single or combination therapy of oral or topical finasteride for women in reproductive age and postmenopausal women with hormonal and nonhormonal androgenetic alopecia found that 5 mg of oral finasteride per day could be an effective and safe treatment in normoandrogenic women with female pattern hair loss (FPHL), especially when used in combination with other drugs, such as topical estradiol and minoxidil 1.
- The typical dose of finasteride used in postmenopausal women ranges from 2.5-5mg daily, which is higher than the 1mg dose commonly prescribed for men.
- Women considering finasteride should first try FDA-approved treatments like topical minoxidil (2% or 5%), which has better established safety and efficacy in female pattern hair loss.
- If finasteride is considered, it should only be used in postmenopausal women or women who cannot become pregnant, and patients should understand its off-label status.
- The medication works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), which is involved in hair follicle miniaturization, but the role of DHT in female pattern hair loss is less clear than in men, which may explain its variable effectiveness in women.
- Other studies have also investigated the use of topical finasteride, which may be a promising alternative to oral finasteride, with preliminary results showing significant decreases in hair loss and increases in total and terminal hair counts 2.
- Ultimately, the decision to use oral finasteride in women with androgenetic alopecia should be made on a case-by-case basis, taking into account the individual patient's medical history, potential risks and benefits, and alternative treatment options.