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. Finasteride is a competitive and specific inhibitor of Type II 5α-reductase with which it slowly forms a stable enzyme complex. Finasteride has no affinity for the androgen receptor In man, the 5α-reduced steroid metabolites in blood and urine are decreased after administration of finasteride.
The role of Finasteride in treating androgenetic alopecia is to inhibit the production of DHT, a potent androgen that contributes to hair loss. By reducing DHT levels, Finasteride helps to slow down hair loss and promote hair growth.
- Key mechanism: Inhibition of Type II 5α-reductase
- Effect on DHT: Decreases DHT levels in blood and urine
- Clinical effect: Slows down hair loss and promotes hair growth in patients with androgenetic alopecia 1
From the Research
Role of Finasteride in Treating Androgenetic Alopecia
- Finasteride is a type 2 5a-reductase inhibitor that has been shown to be effective in treating androgenetic alopecia in males 2, 3.
- It works by decreasing serum and scalp dihydrotestosterone (DHT) levels, which is a contributing cause of androgenetic alopecia 3.
- Clinical trials have demonstrated that finasteride can produce visible hair growth in up to 66% of men with mild to moderate alopecia, and can stop hair loss in 91% of patients 2.
- Finasteride has also been shown to be effective in preventing further hair loss and promoting hair growth in long-term studies 2, 4.
Efficacy and Safety of Finasteride
- Finasteride has been found to be well-tolerated, with minimal adverse effects 3, 5.
- However, there have been reports of associated sexual side effects, such as reduced libido and decreased ejaculate volume 6, 5.
- The safety of finasteride has been established, but patients should be informed of the potential risks and benefits before starting treatment 6.
- Long-term studies have shown that finasteride can maintain its efficacy over time, with some patients experiencing improved results after 5 years of treatment 4.
Age and Efficacy of Finasteride
- Finasteride has been found to be more effective in patients older than 30 years, and in those with higher grades of androgenetic alopecia 4.
- Patients with lower grades of androgenetic alopecia may not experience significant improvements with finasteride treatment 4.
- The efficacy of finasteride can be predicted after the first year of treatment, with some patients experiencing improved results after 1 year 4.