Name Ingredients:
Dutasteride is a compound that is a selective inhibitor of both the type 1 and type 2 forms of 5α-reductase and is used to treat benign prostatic hyperplasia (BPH) in men with an enlarged prostate. This drug is now prescribed off-label to men with pattern hair loss – especially for those looking to achieve hair regrowth beyond what is expected with finasteride.
Key insights:
- The in vitro evidence shows that dutasteride is a dual 5α-reductase inhibitor, meaning that it inhibits both type 1 and type 2 isoforms of 5α-reductase which can be beneficial for patients with androgenetic alopecia.
- The clinical evidence shows that dutasteride treatment can significantly reduce the progression of hair loss in men with male pattern hair loss and is generally well-tolerated, although some sexual side effects have been observed (such as erectile dysfunction, and decreased libido). Dutasteride appears to reduce systemic dihydrotestosterone (DHT) levels by 92-96% and scalp DHT by 50-60%
- Because dutasteride inhibits both isoforms of 5α-reductase, it is thought that it might be more effective at treating hair loss than other inhibitors such as finasteride. This has been shown in clinical studies in which participants were treated with either finasteride or dutasteride. Dutasteride treatment significantly increased total hair and decreased the number of thin hairs compared to finasteride treatment, however most of these studies were completed over 6 months, whereas finasteride can take two years to achieve its full effect. In another comparison of oral treatments – this time with dutasteride, minoxidil and finasteride – it was found that 0.5 mg/day of dutasteride was the most efficacious, followed by finasteride (5 mg/day), minoxidil (5 mg/day), finasteride 1 mg/day), and then minoxidil (0.25 mg/day).
- If you choose to use dutasteride, a dosage of 0.5 mg daily appears to be the best dose as it outperforms finasteride yet does not result in long-term suppression of dihydrotestosterone after stopping – which can happen at higher concentrations.
Additional links:
- Dutasteride: Evidence Quality (Rubric)
- Superiority of dutasteride over finasteride in hair regrowth and reversal of miniaturization in men with androgenetic alopecia: a randomized controlled open-label, evaluator-blinded study
- Efficacy, safety, and tolerability of dutasteride 0.5 mg once daily in male patients with male pattern hair loss: a randomized, double-blind, placebo controlled, phase III study