Eun Dutasteride for AGA Extension Data and What Happened After the Trial Ended
HealthRX.com
Post-trial dutasteride data are limited and mostly from the label
Key numbers
- 153 menMen randomized to dutasteride 0.5 mg or placebo in the Eun trialSource: pubmed.ncbi.nlm.nih.gov, as cited Nov 7, 2026
- 12.2/cm²Mean hair count rise on dutasteride versus placebo in the Eun trialSource: pubmed.ncbi.nlm.nih.gov, as cited Nov 7, 2026
- 5 weeksTerminal half-life of dutasteride at steady state, per the labelSource: dailymed.nlm.nih.gov, as cited Nov 7, 2026
- 4 to 6 monthsHow long dutasteride stays detectable above 0.1 ng/mL after the last doseSource: dailymed.nlm.nih.gov, as cited Nov 7, 2026
- 6 monthsWait before blood donation after last Avodart dose, to avoid transfusion riskSource: dailymed.nlm.nih.gov, as cited Nov 7, 2026
From the public record
Medicare Part D spending on dutasteride
Medicare Part D spending on dutasteride products was $38.3M in 2024 across 958,575 claims, compared with $44.7M in 2023 (-14.4%). Average spending per claim was $39.94, before rebates.
| Measure | Value | Note |
|---|---|---|
| Total spending, 2024 | $38.3M | |
| Total spending, 2023 | $44.7M | |
| Change in spending, 2023 to 2024 | -14.4% | |
| Claims (prescription fills), 2024 | 958,575 | |
| Average spending per claim, 2024 | $39.94 | |
| Dutasteride: spending, 2024 | $31.5M | 955,565 claims |
| Avodart: spending, 2024 | $6.8M | 3,010 claims |
How this was calculated
Summed total spending and claims over every brand and generic row with this generic name in the CMS file, using the Overall manufacturer rows. Combination products excluded. Average per claim is spending divided by claims.
Every single-ingredient dutasteride product in Part D (Dutasteride, Avodart), 2024.
Gross drug cost before manufacturer rebates, so net cost is lower. Part D excludes some uses by law (for example erectile dysfunction, weight loss and hair growth), so claims reflect covered uses only. Compounded products are not included.
At a glance
- Trial / Eun et al., J Am Acad Dermatol 2010
- Participants / 153 men aged 18 to 49 with male pattern hair loss
- Arms / dutasteride 0.5 mg daily vs placebo
- Duration / 6 months
- Hair count change / +12.2/cm² dutasteride vs +4.7/cm² placebo (P=.0319)
- Stated limitation / study limited to 6 months
- Terminal half-life / about 5 weeks
- FDA status / approved for BPH only; hair loss is off-label
What the Eun trial actually enrolled and measured
Eun and colleagues randomized 153 men aged 18 to 49 with male pattern hair loss to dutasteride 0.5 mg daily or placebo for 6 months [1]. Mean hair count rose 12.2/cm² on dutasteride against 4.7/cm² on placebo (P=.0319), with consistent results on subject self-assessment and on investigator and panel photography, and no major difference in adverse events between the groups [1].
There was no finasteride arm. The 917-man trial that compared dutasteride with finasteride is a separate study published in 2014 [3].
How long did the Eun trial last, and what other data exist?
The Eun paper lists its 6-month duration as a limitation [1]. Three other studies of about 6 months give the nearest comparative data.
In 917 men aged 20 to 50, dutasteride 0.5 mg increased hair count and hair width more than finasteride 1 mg (P=.003 and P=.004) and more than placebo (both P<.001) at week 24 [3]. In 416 men aged 21 to 45, dutasteride 2.5 mg, five times the 0.5 mg daily dose, was superior to finasteride 5 mg at 12 and 24 weeks [4]. A single-arm Korean study gave dutasteride 0.5 mg for 6 months to 35 men who had not improved on finasteride 1 mg daily; of the 31 who completed, 24 (77.4%) improved on global photography, hair density rose 10.3% (87 to 96/cm²) and hair thickness rose 18.9% (0.053 to 0.063 mm), and 6 patients (17.1%) had transient sexual dysfunction [5].
What the label says about the drug after you stop
At steady state dutasteride has a terminal half-life of about 5 weeks, reaches 65% of steady state after 1 month and about 90% after 3 months, and stays detectable above 0.1 ng/mL for up to 4 to 6 months after the last dose [2]. The label also says men treated with Avodart should not donate blood until at least 6 months after their last dose, to avoid giving dutasteride to a pregnant transfusion recipient [2].
Questions worth asking
Do sexual side effects accumulate with longer exposure?
In the pooled 2-year BPH trials (2,167 men on Avodart, 2,158 on placebo), months 0 to 6 rates were impotence 4.7% vs 1.7%, decreased libido 3.0% vs 1.4%, ejaculation disorders 1.4% vs 0.5% and breast disorders 0.5% vs 0.2%, and rates fell after 6 months except breast disorders [2]. The label states that across the three pivotal 4-year BPH trials there was no evidence of increased sexual adverse reactions or breast disorders with longer treatment, and that these sexual reactions may persist after discontinuation, with the role of dutasteride in that persistence unknown [2].
A meta-analysis of 15 randomized placebo-controlled hair-loss trials (4,495 men) gave an overall 1.57-fold relative risk of sexual dysfunction; for dutasteride 0.5 mg the relative risk was 1.37 (95% CI 0.81 to 2.32), not statistically significant and based on few dutasteride trials [6]. Those BPH figures come from men aged 47 to 94, mean age 66, not from men in their 20s and 30s treating hair loss [2].
Is dutasteride FDA-approved for hair loss?
No. Avodart is approved for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, alone or with tamsulosin, and it is not approved for prevention of prostate cancer; androgenetic alopecia is an off-label use [2]. Dutasteride inhibits both type 1 and type 2 5-alpha-reductase, while finasteride inhibits mainly type 2 [2].
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Frequently asked questions
Did the Eun trial compare dutasteride with finasteride?
How long does dutasteride stay in the body after the last dose?
Do sexual side effects get worse the longer you take dutasteride?
Is dutasteride FDA-approved for hair loss?
References
Show all 6 referencesHide references
- Eun HC, Kwon OS, Yeon JH, Shin HS, Kim BY, Ro BI, et al. 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. J Am Acad Dermatol. 2010;63(2):252-8.
- U.S. National Library of Medicine, DailyMed. Avodart (dutasteride) soft gelatin capsules, Waylis Therapeutics prescribing information. Avodart (dutasteride) soft gelatin capsules, Waylis Therapeutics label
- Gubelin Harcha W, Barboza Martínez J, Tsai TF, Katsuoka K, Kawashima M, Tsuboi R, et al. A randomized, active- and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia. J Am Acad Dermatol. 2014;70(3):489-498.e3.
- Olsen EA, Hordinsky M, Whiting D, Stough D, Hobbs S, Ellis ML, et al. The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride. J Am Acad Dermatol. 2006;55(6):1014-23.
- Jung JY, Yeon JH, Choi JW, Kwon SH, Kim BJ, Youn SW, et al. Effect of dutasteride 0.5 mg/d in men with androgenetic alopecia recalcitrant to finasteride. Int J Dermatol. 2014;53(11):1351-7.
- Lee S, Lee YB, Choe SJ, Lee WS. Adverse Sexual Effects of Treatment with Finasteride or Dutasteride for Male Androgenetic Alopecia: A Systematic Review and Meta-analysis. Acta Derm Venereol. 2019;99(1):12-17.