Yes, there’s a well-established link between testosterone and bone density, and men with low testosterone are at real risk for osteoporosis. But there’s a genuinely surprising twist here worth knowing: a major, recent clinical trial found that testosterone therapy actually increased fracture risk rather than reducing it, despite improving bone density measurements.
The Established Connection
Hypogonadism is a well-documented, independent risk factor for osteoporosis in men. Studies looking at bone architecture have found that hypogonadal men show measurable deterioration in bone microstructure that isn’t always fully captured by standard bone density scans, suggesting the fracture risk from low testosterone may be even more significant than density numbers alone would indicate. Research using bone biopsies has also found that hypogonadal men with osteoporosis show a higher rate of bone turnover, a marker of bone instability, compared to osteoporotic men with normal testosterone.
Earlier clinical research consistently found that giving testosterone to hypogonadal men increased bone mineral density in the spine, alongside improvements in lean body mass, over about a year of treatment.
The Surprising Finding On Fractures Specifically
Given all that, researchers expected a large trial to confirm that testosterone therapy would reduce fracture risk in hypogonadal men. Instead, a substudy of the large TRAVERSE trial, involving over 5,200 men aged 45 to 80 with hypogonadism and cardiovascular risk factors, found the opposite: 3.5% of men in the testosterone group experienced a fracture during the study, compared to 2.46% in the placebo group, a statistically meaningful increase rather than the expected decrease (New England Journal of Medicine, 2024).
The researchers themselves described this as unexpected, noting it contradicted most prior evidence on testosterone’s effects on bone structure and quality. One proposed explanation is that testosterone may reduce cortical bone in certain ways that don’t show up on standard density scans but could affect overall bone strength.
Why This Doesn’t Simply Cancel Out The Earlier Research
This is a good example of why a single large, well-designed trial can meaningfully update what was previously assumed based on smaller, shorter studies focused on bone density rather than actual fracture outcomes. Bone density is a useful marker, but it isn’t a perfect stand-in for real-world fracture risk, and this trial is a reminder of that gap.
It’s also worth noting this trial specifically studied older men with existing cardiovascular risk factors, so it’s not yet clear whether the same fracture-risk finding applies equally to younger, healthier hypogonadal men.
What This Means Practically
If you have hypogonadism and a personal history of osteoporosis or fracture risk, this is an important, genuinely current finding to discuss with your doctor before starting testosterone therapy. It doesn’t mean testosterone has no bone benefits, but it does mean the fracture-risk picture is more complicated than “higher density automatically means fewer fractures.”
The Bottom Line
Testosterone and bone density are genuinely linked, and low testosterone is a real risk factor for osteoporosis. But the newest, largest evidence on testosterone therapy and actual fractures found an unexpected increase in risk, not a decrease, which is an important update worth taking seriously rather than assuming older density-based research is the final word.
Frequently Asked Questions
Does low testosterone cause osteoporosis?
It’s a well-established, independent risk factor for osteoporosis in men, alongside other contributors like age, diet, and activity level.
Does testosterone therapy increase or decrease fracture risk?
A large 2024 trial found an increased fracture risk with testosterone therapy in older men with hypogonadism and cardiovascular risk factors, contrary to earlier expectations.
Should men with osteoporosis avoid testosterone therapy?
Given the recent findings, this is worth discussing carefully with a doctor, especially for men with an existing fracture or osteoporosis history.
What else supports bone health in men?
Adequate calcium and vitamin D intake, weight-bearing exercise, not smoking, and limiting excess alcohol all support bone health independent of testosterone.