For most people, a DEXA scan is worth it if the results will actually change what you do next. If you’re a woman over 65, a postmenopausal woman with risk factors, or someone tracking body composition changes over time, the scan delivers actionable data you can’t easily get another way. If you’re young, healthy, and just curious, the value drops significantly. The answer depends on what you’re hoping to learn and whether you’ll use the information.
What a DEXA Scan Actually Measures
DEXA (dual-energy X-ray absorptiometry) uses two low-energy X-ray beams to distinguish bone from soft tissue, then soft tissue into fat and lean mass. The result is a detailed map of your body’s composition, region by region. A standard medical scan focuses on the spine and hip to measure bone mineral density. A full-body scan adds fat percentage, lean muscle mass in each limb, and visceral fat, the deep abdominal fat surrounding your organs.
Your bone density result comes as two scores. Your T-score compares you to a healthy 25- to 35-year-old of the same sex and ethnicity. A T-score between +1 and -1 is normal. Between -1 and -2.5 indicates low bone mass (osteopenia). Below -2.5 means osteoporosis. Your Z-score compares you to people your own age, sex, and body size, which helps flag whether bone loss is happening faster than expected for someone like you.
Who Benefits Most From Screening
The U.S. Preventive Services Task Force recommends bone density screening for all women 65 and older and for postmenopausal women younger than 65 who have additional risk factors. Those risk factors include low body weight, a parent who fractured a hip, smoking, and heavy alcohol use. Certain medications, particularly corticosteroids, and conditions like insulin-treated diabetes also raise risk enough to justify earlier screening.
For men, the evidence is less clear. The USPSTF currently says there isn’t enough data to recommend routine screening in men, though individual doctors may order a scan based on specific risk factors like long-term steroid use or a history of fractures.
If you fall into one of the recommended groups, the scan is genuinely worth it. Osteoporosis has no symptoms until a bone breaks, and a fracture in the hip or spine can be life-altering, especially in older adults. Catching low bone density early gives you time to intervene with exercise, nutrition, or medication before a fracture happens.
The Body Composition Case
Outside of bone health, DEXA has gained popularity as a body composition tool, particularly among people focused on fitness, fat loss, or metabolic health. This use is typically elective and not covered by insurance, but the data it provides goes well beyond what a bathroom scale or BMI calculation can tell you.
One of the most useful measurements is visceral adipose tissue, the fat packed around your liver, intestines, and other organs. A large study of middle-to-older aged adults found that higher visceral fat on DEXA was associated with roughly 2.5 times the odds of developing metabolic syndrome in both men and women, independent of BMI or waist circumference. In other words, two people with the same weight and waist size can have very different metabolic risk profiles, and DEXA can reveal that difference.
DEXA also measures appendicular lean mass, the muscle and non-fat tissue in your arms and legs combined. This is the preferred clinical method for identifying sarcopenia, a condition of progressive muscle loss that affects strength and physical function. For older adults or anyone losing weight, tracking lean mass over time helps ensure you’re losing fat rather than muscle.
The practical question is whether you’ll act on this data. If knowing your visceral fat level or lean mass would motivate you to adjust your training or diet, the scan earns its cost. If you’d look at the numbers and shrug, save your money.
Cost and Insurance Coverage
The average cost of a DEXA scan runs over $300 out of pocket. What you actually pay varies widely depending on your location, the facility, and your insurance.
Medicare covers bone density testing once every 24 months if you meet certain criteria: you’re a woman determined to be estrogen-deficient and at risk, your imaging suggests osteoporosis or vertebral fractures, you’re taking or about to start steroid medications, you have primary hyperparathyroidism, or you’re being monitored during osteoporosis treatment. Most private insurers follow similar guidelines.
Body composition scans ordered for fitness or wellness purposes are almost never covered by insurance. Some clinics and gyms offer these for $50 to $150, which is significantly cheaper than a hospital-based scan. The tradeoff is that the quality of the machine and the expertise interpreting results can vary.
How Often You Need One
If your first bone density scan shows normal or only mildly low results, you likely don’t need another one for a long time. An NIH-funded study found that it would take about 15 years for 10% of women with normal bone density at age 67 to develop osteoporosis. Rescreening every two or three years in that group catches very little because bone density simply doesn’t change that fast.
If your results show osteopenia closer to the osteoporosis threshold, or if you’re on treatment for bone loss, more frequent monitoring makes sense. Medicare allows coverage as often as every 24 months, or more frequently when medically necessary.
For body composition tracking, most experts suggest spacing scans at least three to six months apart. Meaningful changes in fat and muscle take time, and scanning too frequently can lead to overinterpreting normal fluctuations.
Safety and What to Expect
DEXA involves extremely low radiation. A spine-plus-hip scan delivers between 1 and 15 microsieverts, depending on the machine. For context, you absorb about 10 microsieverts from natural background radiation every single day just by existing, and a standard chest X-ray delivers 20 to 50 microsieverts. Some newer pencil-beam machines keep the dose under 1 microsievert, making DEXA one of the lowest-radiation imaging tests available.
The scan itself takes 10 to 20 minutes. You lie on a padded table while a scanning arm passes over you. There’s no injection, no fasting, and no enclosed space. You can eat and drink normally beforehand. The only preparation rules: skip calcium supplements or antacids the morning of the exam, wear clothes without metal zippers or belt buckles, and wait at least seven days if you’ve recently had a barium study, a CT or MRI with contrast dye, or a nuclear medicine scan. Those substances can interfere with the X-ray readings.
When It’s Not Worth It
If you’re a premenopausal woman or a man under 50 with no risk factors, a bone density scan is unlikely to tell you anything useful. Your bones are almost certainly fine, and the scan result won’t change your behavior or treatment.
For body composition, the scan loses its value if you treat it as a one-time curiosity rather than a tracking tool. A single snapshot of your fat and muscle distribution is interesting but not particularly actionable on its own. The real power comes from comparing two or more scans over time to see whether your exercise program or dietary changes are producing the results you want at a tissue level. If you’re not planning to follow up, the money is better spent on the habits that would actually move those numbers.