Research brief · 2026-09-09
Does Testosterone Therapy Build Muscle in Older Men?
Testosterone is a prescription medication, and the randomised evidence on muscle in older men does not give one answer. It gives four, depending on who was enrolled and what was measured.
The LITROS trial, published by Barnouin and colleagues in the Journal of Clinical Endocrinology and Metabolism in 2021, enrolled eighty-three frail men over sixty-five with obesity and persistently low testosterone, all on a six-month diet and exercise programme. Both groups lost about nine percent of body weight. Testosterone limited the loss of lean mass and thigh muscle volume, two percent versus four percent on placebo. But muscle strength rose by almost exactly the same amount in both groups, 23 versus 22 percent.
The TOM trial, reported by Travison and colleagues in 2011, took 209 men over sixty-five with mobility limitation and low-to-normal testosterone. Here a daily gel did produce clearer strength gains: 43 percent of the testosterone group reached a meaningful improvement in leg and chest press strength versus 18 percent on placebo. But the trial's safety monitoring board recommended stopping enrolment early after adverse events occurred more often in the testosterone arm.
Two smaller trials add wrinkles. Gharahdaghi and colleagues in 2019 gave eighteen healthy, non-hypogonadal men aged 65 to 75 testosterone or placebo during six weeks of supervised resistance training; testosterone increased lean mass, muscle thickness, strength and net protein accretion beyond training alone. And Dias and colleagues in Andrology in 2015 found that in forty-three men with low testosterone, lean mass rose significantly only in the group given an aromatase inhibitor, not the group given testosterone gel, suggesting conversion to estrogen may matter for the muscle effect.
The limits are substantial. No trial ran beyond twelve months or followed men after stopping. The cardiovascular safety signal from TOM has not been characterised precisely, and the aromatase finding has not been replicated. Whether testosterone therapy is appropriate is a decision for a man and his physician.
Sources
- Barnouin Y, Armamento-Villareal R, Celli A, et al. Testosterone Replacement Therapy Added to Intensive Lifestyle Intervention in Older Men With Obesity and Hypogonadism
- The Journal of Clinical Endocrinology & Metabolism 2021
- Travison TG, Basaria S, Storer TW, et al. Clinical meaningfulness of the changes in muscle performance and physical function associated with testosterone administration in older men with mobility limitation
- The Journals of Gerontology: Series A 2011
- Dias JP, Melvin D, Simonsick EM, et al. Effects of aromatase inhibition vs. testosterone in older men with low testosterone: randomized-controlled trial
- Andrology 2015
- Gharahdaghi N, Rudrappa S, Brook MS, et al. Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men
- Journal of Cachexia, Sarcopenia and Muscle 2019
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