Finasteride

Finasteride (brand names Propecia and Proscar) is a medication that targets hormone-driven hair loss and prostate enlargement.

How it works

Finasteride blocks the enzyme 5-alpha reductase, which converts testosterone into DHT (dihydrotestosterone).
DHT is the main hormone responsible for:

• male pattern baldness
• benign prostatic hyperplasia

Lower DHT → less hair follicle miniaturization and slower hair loss.

What to expect

• Hair loss:
  • Slows or stops shedding in most users
  • Some regrowth possible (mainly crown area)
  • Takes 3–6 months to notice, ~1 year for full effect
• Prostate:
  • Shrinks prostate size over time
  • Improves urinary symptoms

This is where people hesitate:

• Reduced libido
• Erectile dysfunction
• Lower semen volume

Less common:

• Mood changes (including depression)
• Breast tenderness or enlargement

A small number of users report persistent effects after stopping (often referred to as “post-finasteride syndrome”), though this remains debated.

Important notes

• Effects only last while you’re taking it
• Stopping → DHT returns → hair loss resumes
• Women (especially pregnant) should not handle crushed tablets

Bottom line

Finasteride is one of the most effective, clinically proven treatments for hair loss, but it works by altering hormones, so the trade-off is potential side effects.