Dutasteride (Avodart / Zagallo)
Approved for pattern hair loss in South Korea and Japan — but not by the FDA or the EMA.
- Developed by
- GSK
- Current phase
- Approved
- Indications
- Androgenetic alopecia
- Also known as
- Avodart, Zagallo, GG745, dutasteride 0.5 mg
- Last public activity
- March 2026
- Record confidence
- High
Cleared for sale for a hair-loss indication in at least one market.
How it is meant to work
Dutasteride inhibits both type I and type II 5-alpha reductase, where finasteride inhibits type II alone. That broader inhibition is the rationale for using it in hair loss, and Japan's regulator reviewed it for androgenetic alopecia on that basis.
Why it matters
This row is here mostly to fix a common misreading. Dutasteride is frequently described online as either 'not approved' or 'approved' with no qualifier, and both are wrong: it is approved for androgenetic alopecia in some Asian markets and approved only for benign prostatic hyperplasia in the United States and Europe, where any hair-loss use is off-label. Which of those applies depends entirely on where the reader lives.
Where it is approved
Marketing authorisation is granted country by country, for a specific indication. A drug approved for hair loss in one market may be approved only for something else — or not at all — in another.
- JapanPMDAApprovedZagallo· prescription only
Androgenetic alopecia
Authorised for androgenetic alopecia in 2015; exact date not sourced to a primary document.
Regulator filing ↗ - South KoreaMFDSApprovedAvodart· prescription only
Androgenetic alopecia
Authorised for androgenetic alopecia in 2009; exact date not sourced to a primary document.
Peer-reviewed ↗ - FranceANSMOff-labelAvodart· prescription only
Hypertrophie bénigne de la prostate
Widely authorised in France — 28 products, 25 of them marketed — but for benign prostatic hyperplasia. The French summary of product characteristics gives that as the indication; no French authorisation covers hair loss, so use for androgenetic alopecia is off-label here, as in the United States and unlike Japan and South Korea.
Regulator filing ↗ - United StatesFDAOff-labelAvodart· prescription only
Authorised for benign prostatic hyperplasia, not for hair loss. Use for androgenetic alopecia is off-label.
Peer-reviewed ↗
Development history
- Phase 3
First Phase 3 trial on record: NCT00441116 — A Study To Assess The Efficacy And Safety Of Dutasteride 0.5mg Once Daily For 6 Months In The Treatment Of Male Subjects With Androgenetic Alopecia
ClinicalTrials.gov ↗
Registered trials
Pulled automatically from ClinicalTrials.gov. Matching is by name and development code, so occasional gaps are possible — tell us if you spot one.
Assessment of Dutasteride Topical Solution in Male Androgenetic Alopecia
Moogene Medi Co., Ltd · n=30 · April 2026
MALE HAIR LOSS - Treatment With Dutasteride Mesotherapy x Dutasteride MMP Technique (Injections With Tattoo Machine)
Clinica Dermatologica Arbache ltda · n=60 · October 2023
Clinical Trial of Safety and Efficacy of Daily Application of Topical Dutasteride in Men With Androgenic Alopecia.
Fundacion para la Investigacion Biomedica del Hospital Universitario Ramon y Cajal · n=45 · September 2022
Sexual Function in Men Receiving Dutasteride for Androgenetic Alopecia
Stiefel, a GSK Company · n=117 · July 2014
Bioequivalence Study of Dutasteride Five 0.1 mg and One 0.5 mg Soft Gelatin Capsules in Healthy Male Volunteers
GlaxoSmithKline · n=36 · September 2013
A Long-term Study to Determine Safety and Efficacy of Dutasteride in Male Subjects With Androgenetic Alopecia
GlaxoSmithKline · n=120 · April 2013
Dutasteride Versus Placebo and Finasteride in Men With Androgenetic Alopecia
GlaxoSmithKline · n=917 · October 2010
AVODART® Alopecia Post-marketing Surveillance (PMS)
GlaxoSmithKline · n=712 · April 2010
A Study To Assess The Efficacy And Safety Of Dutasteride 0.5mg Once Daily For 6 Months In The Treatment Of Male Subjects With Androgenetic Alopecia
GlaxoSmithKline · n=153 · December 2006
Listing a trial is not a recommendation to join one. Eligibility, risks and costs vary enormously — discuss any trial with your own doctor first.
Sources
- Long-term efficacy and safety of dutasteride 0.5 mg in Korean men with androgenetic alopecia: 5-year data — Peer-reviewed, February 2024
- Report on the Deliberation Results — Zagallo Capsules (dutasteride), androgenetic alopecia — Regulator filing, June 2015