What is the role of adding finasteride (1mg orally once daily) to the treatment regimen for male pattern baldness?

Adding Finasteride 1mg Daily for Male Pattern Baldness

Finasteride 1mg orally once daily is an effective, evidence-based treatment for male pattern baldness that promotes hair growth and prevents further hair loss in the majority of men, with durable benefits maintained over 5 years of continuous use.

Efficacy and Expected Outcomes

Finasteride 1mg daily demonstrates robust clinical efficacy with measurable improvements beginning at 12 weeks and continuing through long-term treatment 1, 2:

• 58-66% of men show improvement in hair growth based on global photographic assessment at 1-2 years 1, 2
• 83% of men have no further hair loss compared to baseline after 2 years, versus only 28% with placebo 3
• Hair count improvements are durable over 5 years of continuous treatment, while placebo leads to progressive hair loss 1
• The vertex (crown) responds best to treatment; anterior scalp and hairline show minimal response 4

Mechanism and Pharmacology

Finasteride works by competitively inhibiting Type II 5α-reductase, blocking conversion of testosterone to dihydrotestosterone (DHT), the androgen responsible for male pattern hair loss 5:

• Reduces serum DHT by approximately 70% with daily 5mg dosing (the 1mg dose for hair loss produces similar but slightly less suppression) 5
• Circulating testosterone increases by 10-20% but remains within physiologic range 5
• Bioavailability is 63% and is not affected by food 5
• Maximum effect occurs 8 hours after dosing with suppression maintained throughout 24-hour interval 5

Safety Profile and Sexual Side Effects

The overall incidence of sexual dysfunction is low but statistically significant compared to placebo 3, 6:

• 3.8% experience sexual side effects (decreased libido, ejaculation disorders, erectile dysfunction) versus 2.1% with placebo 3
• Sexual adverse events reverse upon discontinuation and many resolve even with continued therapy 3, 6
• Breast-related effects occur in 2.3% (gynecomastia, breast tenderness) versus 0.74% on placebo 7
• No new safety concerns emerged during 5-year follow-up studies 1
• Treatment is generally well tolerated with only 7.7% reporting treatment-related adverse events versus 7.0% with placebo 3

Critical Precautions

PSA levels decrease by approximately 50% after 12 months of finasteride therapy, which must be considered when screening for prostate cancer 7, 5:

• Inform patients and their physicians about this PSA-lowering effect
• Double the PSA value when interpreting results in men on finasteride for prostate cancer screening

Finasteride is absolutely contraindicated in pregnant women due to risk of hypospadias in male fetuses 3:

• Women of childbearing potential should not handle crushed or broken tablets
• Pregnant women must avoid exposure to semen from men taking finasteride

Treatment Protocol

Initiate finasteride 1mg orally once daily 2, 6:

• Minimum trial duration: 12 weeks to assess initial response 2
• Optimal assessment timepoint: 48 weeks for full evaluation of efficacy 2
• Long-term maintenance: Continue indefinitely as benefits are maintained only with ongoing treatment 1
• Discontinuation results in return to baseline within approximately 2-3 months 5

Patient Counseling Points

Provide comprehensive informed consent before initiating treatment 6:

• Set realistic expectations: finasteride maintains existing hair and may promote regrowth, but does not eliminate risk of baldness
• Explain that 58-66% will see improvement, while 83% will prevent further loss 1, 3
• Discuss sexual side effects (3.8% incidence) and their reversibility 3, 6
• Emphasize need for continuous treatment to maintain benefits 1
• Inform about PSA-lowering effect for future prostate cancer screening 7

Combination Therapy Considerations

Finasteride can be used as background therapy with other modalities 8:

• Platelet-rich fibrin (PRF) protocols often include finasteride as part of combined therapy for androgenetic alopecia 8
• The evidence suggests complex combined therapy protocols applied early yield best results 8

Common Pitfalls to Avoid

• Do not expect anterior hairline regrowth: The vertex responds best; anterior scalp shows minimal response 4
• Do not discontinue prematurely: Minimum 12 weeks needed to assess response, with optimal evaluation at 48 weeks 2
• Do not forget PSA counseling: Failure to inform patients about PSA-lowering can complicate future prostate cancer screening 7
• Do not prescribe to women of childbearing potential: Absolute contraindication due to teratogenic effects 3