The short answer
For men 65 and older with clearly low testosterone and symptoms, a year of treatment helped some things and not others. The NIH-funded Testosterone Trials found real benefits for sexual function, anemia and bone density, a small lift in mood, and no meaningful gain in energy, walking distance or memory. One imaging study raised a cardiovascular question that later research has partly answered.
That mixed result is useful precisely because it is mixed. It tells an older man what testosterone can reasonably be expected to do, and what it should not be sold as.
How were the Testosterone Trials set up?
The Testosterone Trials were seven coordinated, placebo-controlled studies run at 12 U.S. academic medical centers. The main report in the New England Journal of Medicine describes 790 men aged 65 or older whose testosterone averaged below 275 ng/dL and who had symptoms suggesting low testosterone. Funding came from the National Institutes of Health and others.
Each man used testosterone gel or placebo gel for one year, with the dose adjusted to bring levels into the normal range for men aged 19 to 40. Men joined whichever of three main trials matched their symptoms (sexual function, physical function or vitality), and four more trials measured anemia, bone, cognition and coronary plaque across the group.
The question behind the design was a live one. Testosterone falls as men age, yet the benefit of raising it in older men had not been established, as the investigators noted at the outset. These trials were built to test benefit directly, with enough men to see whether each symptom actually moved.
Outcome by outcome
Here is each trial with its headline result:
| Trial | Main question | Result after one year |
|---|---|---|
| Sexual function | Does sexual activity improve? | Yes: more sexual activity, desire and erectile function |
| Physical function | Do more men walk 50 m farther in 6 minutes? | Not significant in that trial; significant across all men (20.5% vs 12.6%) |
| Vitality | Does fatigue improve? | No; mood and depressive symptoms slightly better |
| Anemia | Does hemoglobin rise in anemic men? | Yes, in unexplained and known-cause anemia |
| Bone | Does bone density rise? | Yes, most in the spine |
| Cognitive function | Does memory improve? | No |
| Cardiovascular | Does noncalcified plaque slow? | No; it grew more on testosterone |
Where did testosterone help?
Sexual function showed the clearest benefit. Men on testosterone reported more sexual activity, more desire and better erectile function, which the authors described as a moderate benefit. Mood and depressive symptoms also improved slightly, even though the vitality trial missed its main goal.
The blood and bone results were the most striking. In the anemia trial, 54% of men with unexplained anemia raised hemoglobin by at least 1.0 g/dL on testosterone, compared with 15% on placebo, and 58.3% were no longer anemic at a year versus 22.2%. Men whose anemia had a known cause improved too. The same effect has a flip side: six men who were not anemic at the start ended the year with hemoglobin above 17.5 g/dL, which is why blood counts are rechecked during treatment, as our page on hematocrit testing for men explains. The bone trial of 211 men found spine trabecular bone density rose 7.5% on testosterone against 0.8% on placebo, and estimated spine bone strength rose 10.8% against 2.4%. Our page on low hemoglobin in men covers the anemia side.
Where did it fall short?
Energy, walking and memory did not respond the way many men hope. The vitality trial found no significant improvement in fatigue scores. In the physical function trial, the share of men who walked at least 50 meters farther did not differ significantly, although it did when all participants were pooled. In the cognitive function trial, 493 men with age-associated memory impairment showed no improvement in memory, executive function or spatial ability.
For a man whose main complaint is fatigue or fog, that is a reason to widen the search rather than reach straight for hormones. Sleep apnea, thyroid problems, low iron, depression and medicines all produce the same tiredness, and our page on blood tests for fatigue in men lists what is worth checking.
The cardiovascular trial raised a flag. Among 138 men analyzed with coronary CT scans, the plaque study found a significantly greater increase in noncalcified plaque volume on testosterone, an estimated 41 cubic millimeters more than placebo. No major cardiovascular events occurred in either group, and the authors said larger studies were needed. The bone trial’s authors likewise noted that a larger, longer study would be needed to show whether denser bone meant fewer fractures.
What it means for men over 65 today
Later research answered some of those open questions, and not always in testosterone’s favor. The TRAVERSE trial found no increase in heart attacks or strokes among middle-aged and older men at high cardiovascular risk, which our TRAVERSE trial breakdown explains. Its fracture analysis, however, found clinical fractures in 3.50% of men on testosterone and 2.46% on placebo, so higher bone density did not translate into fewer broken bones.
For an older man, that leaves a practical set of expectations:
- Reasonable goals: better desire and sexual function, correction of anemia linked to low testosterone, a small mood lift.
- Unlikely goals: more energy on its own, faster walking, sharper memory.
- Things to watch: hematocrit, prostate monitoring, heart and clot symptoms, and fall risk.
Our answer on whether men over 65 can start TRT and our page for men over 60 translate this into a decision.
How Ultimate Male evaluates older men
At our San Gabriel and Downey clinics, men in their sixties and seventies get the same standard as anyone else: two low morning testosterone results and symptoms that fit, after other causes are considered. The TRT pre-screening panel checks total testosterone, estradiol, PSA and a complete blood count, and it comes bundled with the first consultation.
A PA-C or MD then talks through which of your goals the evidence supports and which it does not, before any decision about testosterone therapy. If treatment starts, follow-up visits and labs keep watch on blood counts and prostate markers. The free 10-minute call is a good place to bring your list of questions.
