Two Major Trials Settle Key Questions on Testosterone Therapy Safety and Efficacy
A narrative review of the T Trials and TRAVERSE trial clarifies what testosterone therapy actually delivers — and what it doesn't — for older men.
Summary
A new review from Harvard's Brigham and Women's Hospital synthesizes findings from two landmark randomized controlled trials — the Testosterone Trials and the TRAVERSE trial — to clarify the real-world benefits and risks of testosterone therapy in middle-aged and older men. Testosterone improved sexual function and mood but failed to boost physical function, vitality, or cognitive performance. Critically, it did not increase major adverse cardiovascular events in men already at high cardiovascular risk, addressing a long-standing safety concern. However, an unexpected finding was a higher fracture rate in the testosterone group, warranting caution. The authors conclude that testosterone therapy is appropriate for men with symptomatic androgen deficiency but only for outcomes where evidence supports benefit.
Detailed Summary
Testosterone therapy is widely prescribed for age-related low testosterone, yet its true risk-benefit profile has long been contested. This narrative review from endocrinologists at Harvard Medical School synthesizes the two most rigorous randomized controlled trials ever conducted on the subject — the Testosterone Trials and the TRAVERSE trial — to give clinicians and patients a clearer evidence base for decision-making.
The Testosterone Trials enrolled men aged 65 and older with age-related syndromic androgen deficiency. Compared with placebo, testosterone therapy significantly improved sexual function and mood. However, no meaningful benefits were observed for physical function, vitality, or cognitive function — domains many patients hope testosterone will address.
The TRAVERSE trial focused on cardiovascular safety in men aged 45 to 80 with elevated cardiovascular risk. A major concern has been whether testosterone increases heart attack and stroke risk. The trial found testosterone was noninferior to placebo for major adverse cardiovascular events, providing important reassurance. Prostate-related events were also comparable between groups. However, fracture rates were unexpectedly higher in the testosterone group, a finding that deserves further investigation and clinical vigilance.
Taken together, the evidence supports a targeted approach: testosterone therapy may be appropriate for middle-aged and older men with confirmed syndromic androgen deficiency who are specifically seeking to improve sexual function or mood. For outcomes not supported by the data — including vitality, physical performance, and cognitive function — alternative strategies should be explored rather than defaulting to testosterone.
The review underscores that testosterone is not a broad-spectrum anti-aging treatment. The unexpected fracture signal adds an important safety caveat. Clinicians should weigh individual patient profiles carefully and set realistic expectations when counseling men considering testosterone therapy.
Key Findings
- Testosterone therapy improved sexual function and mood in older men with androgen deficiency but not physical function, vitality, or cognition.
- TRAVERSE trial confirmed testosterone is noninferior to placebo for major adverse cardiovascular events, even in high-risk men.
- Prostate-related adverse events were similar between testosterone and placebo groups across trials.
- Fracture rates were unexpectedly higher in the testosterone group — an important and underappreciated safety signal.
- Authors recommend limiting testosterone use to domains where efficacy is demonstrated, not as a broad anti-aging intervention.
Methodology
This is a narrative review synthesizing data from two large randomized controlled trials: the Testosterone Trials (men ≥65 with age-related androgen deficiency) and the TRAVERSE trial (men aged 45–80 with high cardiovascular risk). The authors critically evaluate trial design, primary and secondary outcomes, and methodological limitations of each study.
Study Limitations
This summary is based on the abstract only, as the full text was not accessible. As a narrative review rather than a systematic review or meta-analysis, the synthesis may reflect author selection and interpretation biases. The fracture finding from TRAVERSE requires further mechanistic investigation before firm clinical guidance can be issued.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.
Enter your email to subscribe: