What is the recommended dose of finasteride (Finasteride) for benign prostatic hyperplasia (BPH) and androgenetic alopecia?

From the Guidelines

The recommended dose of finasteride for benign prostatic hyperplasia (BPH) is 5 mg once daily, while for androgenetic alopecia (male pattern baldness), the recommended dose is 1 mg once daily. Finasteride can be taken with or without food, and patients should maintain consistent daily dosing for optimal results. For BPH, symptom improvement may begin within a few months, but 6-12 months of therapy is typically needed to assess full effectiveness 1. For hair loss, visible results usually take 3-6 months of continuous use, and ongoing treatment is necessary to maintain benefits, as hair loss will resume if the medication is discontinued. Finasteride works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), a hormone that contributes to prostate enlargement and hair follicle miniaturization. Potential side effects include decreased libido, erectile dysfunction, and decreased ejaculate volume, which occur in a small percentage of users, as reported in studies such as the PCPT trial 1. Women who are pregnant or may become pregnant should not handle crushed tablets due to potential risks to male fetuses.

Some key points to consider when prescribing finasteride include:

• The medication's slow onset of action, with symptom improvement taking several months to become apparent 1
• The importance of consistent daily dosing for optimal results
• The need for ongoing treatment to maintain benefits, particularly for hair loss
• The potential side effects, which can include decreased libido, erectile dysfunction, and decreased ejaculate volume 1
• The need for women who are pregnant or may become pregnant to avoid handling crushed tablets due to potential risks to male fetuses.

It is also important to note that finasteride has been shown to reduce the risk of prostate cancer, as demonstrated in the PCPT trial 1, and may be considered as a treatment option for prevention in certain cases. However, the treatment duration required for best outcome is still a topic of debate, with some studies suggesting a duration of 7 years for primary prevention 1.

From the FDA Drug Label

Finasteride tablets 5 mg/day was initially evaluated in patients with symptoms of BPH and enlarged prostates by digital rectal examination in two 1-year, placebo-controlled, randomized, double-blind studies and their 5-year open extensions In patients treated for three months, prostate volume, which declined by approximately 20%, returned to close to baseline value after approximately three months of discontinuation of therapy. Daily dosing of finasteride tablets at 5 mg/day for up to 4 years has been shown to reduce the serum DHT concentration by approximately 70%. In a separate study in healthy men treated with finasteride 1 mg per day (n=82) or placebo (n=69), mean circulating levels of testosterone and estradiol were increased by approximately 15% as compared to baseline, but these remained within the physiologic range

The recommended dose of finasteride for benign prostatic hyperplasia (BPH) is 5 mg/day. For androgenetic alopecia, the recommended dose is 1 mg/day 2, 2.

• Key points:
  • Dose for BPH: 5 mg/day
  • Dose for androgenetic alopecia: 1 mg/day
  • Duration of treatment: up to 4 years for BPH, with a therapeutic trial of at least 6 months to assess beneficial response in symptom relief.

From the Research

Finasteride Dose for Benign Prostatic Hyperplasia (BPH) and Androgenetic Alopecia

• The recommended dose of finasteride for BPH is 5 mg/day, as shown in a study published in The New England Journal of Medicine 3.
• This dose has been found to decrease symptoms of urinary obstruction, increase urinary flow, and decrease prostatic volume.
• However, a lower dose of 2.5 mg/day has also been found to be effective in maintaining subjective and objective improvements in urinary obstruction, with no significant changes in maximum flow rate, voided volume, or AUA symptom score 4.
• For androgenetic alopecia, the recommended dose of finasteride is 1 mg/day, as established in a study published in The Journal of Investigative Dermatology 5.
• This dose has been found to be effective in treating male pattern hair loss, with a well-established safety profile.
• A study published in The Lancet Oncology found that 1 mg/day finasteride lowers serum PSA concentration, and therefore the existing recommendation for the adjustment of serum PSA concentration in prostate-cancer screening in men taking 5 mg/day finasteride should also apply to men taking the 1 mg/day preparation for male-pattern hair loss 6.

Comparison of Finasteride Doses

• The 5 mg/day dose is more effective in reducing symptoms of BPH, but may have a slightly increased risk of sexual dysfunction 3.
• The 1 mg/day dose is effective in treating androgenetic alopecia, and has a well-established safety profile 5.
• The 2.5 mg/day dose may be a viable alternative for BPH treatment, with minimal changes in urinary obstruction symptoms and flow rate 4.

Safety and Efficacy

• Finasteride has a well-established safety profile, with minimal adverse effects reported in clinical trials 5, 3.
• However, a study published in Archives of Andrology found that long-term use of finasteride may affect sperm quality and meiotic segregation 7.
• Further research is needed to fully understand the effects of finasteride on sperm quality and fertility.