SOURCE-LINKED STUDY SUMMARY
Effect of testosterone supplementation with and without a dual 5α-reductase inhibitor on fat-free mass in men with suppressed testosterone production: a randomized controlled trial.
Abstract summarizedQuality not appraised
- What was studied
- A randomized trial tested whether blocking testosterone conversion to DHT changes gains in fat-free mass and strength.
- Who / model studied
- 139 healthy men aged 18 to 50 were randomized; 102 completed treatment.
- Studied dose & schedule
- Testosterone enanthate 50, 125, 300 or 600 mg weekly for 20 weeks, plus dutasteride 2.5 mg daily or placebo; routes were not specified in the abstract.
- What the study found
- Dutasteride did not significantly alter dose-adjusted fat-free-mass gains or strength changes. Conversion to DHT was not necessary for testosterone’s anabolic response under these study conditions.
- Limitations & context
- Only 102 of 139 randomized men completed the 20-week intervention. These short-term results do not establish long-term equivalence or safety.
Read summary source ↗ · Prepared 9/25/2026 · AI-assisted, source-based summary
Review record & corrections
Summary prepared: . Source scope: abstract. This is an AI-assisted source summary, not an independent clinician sign-off.
No public field-by-field revision history is available for this card yet. The date above is the summary date, not proof that every field was updated then.
Inspect the source · Correction policyResearch findings apply to the population and conditions studied. This educational summary is not a treatment recommendation or a formal assessment of study quality.
Original publication ↗ · DOI: 10.1001/jama.2012.227