Description
Dutasteride (Avodart) is a dual inhibitor of 5α-reductase Type I and Type II - the next-generation compound after Finasteride. While Finasteride only inhibits Type II, Dutasteride blocks both isoforms and lowers DHT levels by 90-95% (vs 70% under Finasteride).
Per study reports the stronger DHT lowering means deeper targeting of androgenetic alopecia and benign prostatic hyperplasia (BPH). Direct comparison studies show Dutasteride as superior in regrowth action in the hair area and in prostate volume reduction in BPH.
Pharmacokinetically Dutasteride has an extremely long half-life of about 5 weeks. Steady-state is reached only after 6 months. This also means action persists for months after discontinuation - practically relevant for users wanting to switch between compounds.
Clinically Dutasteride is approved as Avodart for BPH (in the US and EU). Off-label application in alopecia is common; in some countries also on-label.
Known effects are similar to Finasteride, but tend to be more pronounced due to stronger DHT lowering: sexual effects (libido, erection, ejaculate volume), rarely mood changes. Persistence after discontinuation may be longer due to the long half-life.
You can order Dutasteride as oral tablets in one bottle with 1mg per tablet.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
Dutasteride is an approved dual 5α-reductase inhibitor and is well characterized. Its side effect profile resembles that of Finasteride but tends to be more pronounced due to the stronger DHT lowering.
Documented in clinical studies:
- Sexual side effects: libido decrease, erectile problems and reduced ejaculate volume are documented and tend to occur more frequently or more markedly than under Finasteride, since Dutasteride lowers DHT levels by 90-95 percent.
- Long half-life: with a roughly 5-week half-life the compound is sluggish. Effects and side effects persist for months after discontinuation, and a full wash-out takes correspondingly long.
- Mood changes: rarer than the sexual effects, but described in the literature.
- Persistence after discontinuation: effects can last longer than with Finasteride due to the long half-life, analogous to the post-finasteride problem discussed there.
This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- Efficacy and safety of a dual inhibitor of 5-alpha-reductase types 1 and 2 (dutasteride) in men with benign prostatic hyperplasia - Urology 2002, Roehrborn et al: pooled Phase III approval data for dutasteride in BPH.
- Marked Suppression of Dihydrotestosterone in Men with Benign Prostatic Hyperplasia by Dutasteride, a Dual 5-alpha-Reductase Inhibitor - JCEM 2004, Clark et al: study documenting ~90% DHT suppression under dutasteride.
- The importance of dual 5-alpha-reductase inhibition in the treatment of male pattern hair loss: Results of a randomized placebo-controlled study of dutasteride versus finasteride - JAAD 2006, Olsen et al: randomized head-to-head study with dutasteride superior in regrowth.
- Effect of Dutasteride on the Risk of Prostate Cancer - NEJM 2010, Andriole et al: REDUCE 4-year trial on prostate cancer risk reduction with dutasteride.
- Comparison of dutasteride and finasteride for treating benign prostatic hyperplasia: the Enlarged Prostate International Comparator Study (EPICS) - BJU International 2011, Nickel et al: 12-month head-to-head comparison of dutasteride versus finasteride in BPH.




