TRT and Bone Density: How Testosterone Affects Bone Health and Fracture Risk in Men

Bone health is not the first thing most men think about when considering testosterone replacement therapy. Energy, muscle mass, sexual function, and mood get most of the attention. But testosterone is a major driver of bone mineral density in men, and prolonged low testosterone can silently weaken the skeleton over years.

The relationship between TRT and bone health is more nuanced than it first appears. Treatment consistently improves bone density measurements in hypogonadal men, but whether that improvement translates into fewer broken bones remains an active question in the research. Here is what the evidence shows, what the major guidelines say, and what men should discuss with a licensed clinician.

Why Testosterone Matters for Bone

Bone is living tissue that constantly remodels itself. Two cell types drive the cycle: osteoblasts build new bone, and osteoclasts break down old bone. Testosterone influences this balance through two distinct hormonal pathways.

Through direct androgenic signaling, testosterone (and its more potent metabolite dihydrotestosterone, or DHT) binds to androgen receptors on osteoblasts. This promotes bone formation and helps maintain cartilage at joint surfaces. In men with low testosterone, osteoblast activity declines, and the bone-building side of the equation slows down.

Through aromatization to estradiol, about 85 percent of circulating estradiol in men is produced when testosterone is converted by the aromatase enzyme. Estradiol acting through estrogen receptor alpha (ER-alpha) is the primary brake on bone resorption in men. Men with a genetic inability to produce or use estradiol develop extremely low bone density and are at high risk for osteoporosis, despite having normal or near-normal testosterone levels. When aromatase inhibitors are given to hypogonadal men for 12 months, bone density drops further, confirming that estrogen from testosterone is doing important protective work.

When testosterone declines with age or primary hypogonadism, the RANKL-to-OPG ratio shifts toward the osteoclast side. RANKL increases from osteoblasts, more osteoclasts mature, and bone resorption outpaces bone formation. Over months and years, this drives measurable bone mineral density loss.

How Common Is Low Bone Density in Aging Men?

Osteoporosis is often thought of as a women's condition, but men account for a significant share of fragility fractures. The prevalence of osteoporosis in men rises sharply with age: under 10 percent at age 40, about 13 percent at ages 70 to 75, 18 percent at ages 75 to 80, and over 21 percent after age 80.

Men who suffer a femoral neck fracture face roughly four times the incidence of mortality-associated complications compared with women. Part of the reason is that bone density testing (DEXA scans) is less frequently ordered in men, so osteoporosis is often discovered only after a fracture has occurred.

Studies have found that anywhere from 7 to 58 percent of men presenting with osteoporosis also have hypogonadism, though that range reflects major differences in study design, definitions, and confounding factors such as smoking, physical inactivity, metabolic syndrome, and glucocorticoid use.

What the Research Shows About TRT and Bone Density

A meta-analysis of 29 randomized controlled trials involving over 1,000 men found that TRT improved lumbar spine bone mineral density by an average of 3.7 percentage points compared with placebo over treatment periods ranging from several months to multiple years.

Multiple individual trials confirm this pattern: TRT reliably increases BMD at the lumbar spine, femoral neck, and trochanter in hypogonadal men. The greatest gains typically occur during the first 12 to 24 months of treatment. Men with lower baseline BMD see the largest absolute improvements.

However, there are limits to the evidence. Very few trials followed participants for more than three years, making it difficult to determine whether continued TRT yields sustained gains or a plateau. Some trials with shorter follow-up periods or cohorts that did not have low baseline BMD showed no significant BMD improvement.

The TRAVERSE Fracture Data: An Important Caveat

The large TRAVERSE trial, which randomized over 5,200 men aged 45 to 80 with hypogonadism and established cardiovascular risk or disease to testosterone gel or placebo, provided the most rigorous cardiovascular safety data to date. A secondary analysis published in the New England Journal of Medicine in 2023 also examined fracture outcomes.

Despite the well-established BMD improvements seen in TRT, testosterone treatment did not significantly reduce the incidence of clinical fractures compared with placebo over the trial follow-up period. The study found a numerically higher, though not statistically significant in all endpoints, incidence of fractures in the testosterone group across prespecified fracture categories.

There are several plausible explanations that researchers have noted. The trial population was not selected for low bone density, so many participants may have had adequate bone health at baseline. Falls risk — driven by balance, muscle strength, neuropathy, medications, and other factors — may have offset any theoretical benefit from modest BMD gains. And the timeline for fracture prevention may be longer than the trial duration.

The bottom line from TRAVERSE: TRT improves bone density measurements, but that does not automatically mean fewer broken bones. A comprehensive approach to fracture prevention must address more than just hormone levels.

When Androgen Deprivation Destroys Bone

Perhaps starkest evidence of testosterone's role in bone health comes from men treated with androgen deprivation therapy (ADT) for prostate cancer. Within the first year of medical castration, men lose between 2 and 8 percent of their bone mineral density. ADT increases the risk of clinical osteoporosis by five to tenfold and raises the risk of proximal femur fractures by 50 to 80 percent.

This is an extreme situation that is not analogous to natural age-related testosterone decline, but it demonstrates the magnitude of testosterone's effect on the skeleton. It is also why men on ADT are routinely monitored for bone health and may receive bisphosphonates or denosumab.

Should You Get a DEXA Scan Before Starting TRT?

Current clinical guidelines from the American Urological Association and the Endocrine Society do not recommend routine bone density screening for all men before starting TRT. The AUA guideline does note that patients should be informed that TRT may improve bone mineral density among its other potential benefits.

However, a DEXA scan may be reasonable to discuss with your clinician if you are an older man considering TRT and you have any of the following:

• A history of fragility fracture (a bone break from a standing-height fall)
• Prolonged glucocorticoid or corticosteroid use
• Family history of osteoporosis or hip fracture
• Heavy alcohol use or smoking history
• Unexplained weight loss or malabsorption (e.g., celiac disease)
• Low body weight or sarcopenia
• Conditions linked to secondary osteoporosis (hyperparathyroidism, hyperthyroidism, hypogonadism)
• Age over 70 without prior screening

Bone density results are reported as T-scores. A T-score of −2.5 or below defines osteoporosis. A T-score between −1.0 and −2.5 defines osteopenia (low bone mass). These numbers help determine whether bone protection strategies beyond hormone therapy are warranted.

TRT Is Not a Bone Drug

It is important to be clear: major guidelines do not recommend TRT solely to prevent or treat osteoporosis. First-line pharmacological treatment for men with osteoporosis typically involves vitamin D, calcium optimization, and antiresorptive medications such as bisphosphonates or denosumab.

TRT is recommended only for men who have symptomatic hypogonadism confirmed by laboratory testing, and in that context, the potential BMD improvement is one of several expected benefits rather than the primary indication. A man prescribed TRT purely to improve bone density, without symptomatic low testosterone, should discuss alternative osteoporosis treatments with his clinician first.

Supporting Bone Health Alongside TRT

Whether or not a man is on TRT, several evidence-based measures support bone strength. These are topics to discuss with a healthcare provider:

Resistance training and weight-bearing exercise. Mechanical loading stimulates osteoblast activity. Men on TRT who combine treatment with progressive resistance training and impact exercise see greater improvements in bone density and muscle mass than those relying on medication alone. Resistance training also reduces fall risk through improved balance and grip strength.

Adequate calcium intake. Men over 50 are generally advised to consume about 1,000 to 1,200 mg of elemental calcium daily, with preference for dietary sources over supplements when possible.

Vitamin D. Vitamin D status affects calcium absorption and bone metabolism. Clinicians typically aim for 25-hydroxyvitamin D levels above 20 to 30 ng/mL, depending on the guideline.

Protein intake. Adequate protein supports both muscle mass and skeletal integrity. Sarcopenia and osteoporosis often co-occur in aging men.

Avoid smoking and excessive alcohol. Both are independent risk factors for reduced bone density and increased fracture risk, and both can interfere with testosterone production.

Key Takeaways

Testosterone plays a dual role in male bone health: direct androgenic support for bone formation and indirect estradiol-mediated protection against excessive bone resorption. Low testosterone is consistently associated with reduced bone mineral density, and TRT improves BMD in hypogonadal men. But the TRAVERSE trial demonstrated that BMD improvements do not automatically translate into fewer clinical fractures.

TRT is not recommended as a standalone bone-protective treatment. The right approach combines hormone optimization when indicated, fracture risk assessment, targeted screening for men with known risk factors, and lifestyle measures that support both the skeleton and the muscles that protect it. Men considering TRT should discuss their individual bone health risk profile with a licensed clinician who can determine whether baseline DEXA screening is appropriate.

This article provides general educational information and is not a substitute for professional medical care. Decisions about TRT, bone density testing, and osteoporosis treatment should be made with a qualified healthcare provider.