Is a DEXA Scan Safe? Radiation Levels Explained
Author: Sabila S., MBBS
Medically reviewed by: Dr Sam Botchey, MBBS, MSc, FFSEM, MRCEM
DEXA scans are generally considered to carry a low level of risk for most healthy adults. The primary safety consideration involves the low-dose X-rays used to determine bone density and body composition.
1–4 µSv | 5–10 min | Non-Invasive |
Radiation dose | Scan duration | No needles, no discomfort |
Why Does a DEXA Scan Use X-Rays?
DEXA stands for Dual-Energy X-ray Absorptiometry. It is widely regarded as one of the most reliable methods for determining bone mineral density (BMD) and providing body composition data, including muscle mass and visceral fat.
The term Dual-Energy relates to the fact that there are two X-ray beams of different energy levels. One X-ray beam is mostly absorbed by soft tissues (muscle and fat). The second is absorbed by bone.
The difference between how the two X-ray beams pass through the body allows the DEXA scanner to provide a precise map of your body’s physical characteristics. Since it uses energy beams, a limited amount of ionising radiation is required to create the data.
Is a DEXA Scan Safe? Navigating Radiation Levels
For most adults, a DEXA scan is considered a low-dose imaging test. NHS guidance states that bone density DEXA scans use much less radiation than standard X-rays, and multiple radiology sources describe the test as quick, non-invasive and low-risk when appropriately used.
To understand how much radiation a DEXA scan produces, a typical body composition scan generates approximately 1–4 µSv of radiation.
To put these figures in context: we are constantly exposed to natural background radiation from the sun, the soil, and even our food. Comparing a scan to these everyday sources helps illustrate the relative dosage levels involved:
Source of Radiation | Approximate Dose |
|---|---|
DEXA Scan (Body Composition) | 1 to 4 µSv |
One day of natural background radiation in the UK | ~7 µSv |
A standard chest X-ray | ~100 µSv |
A screening mammogram | ~400 µSv |
WHAT THE FIGURES SHOW As shown in the table above, the radiation dose from a DEXA scan is lower than that of a standard diagnostic chest X-ray. This dose falls within a low range, broadly comparable to the natural background radiation experienced during a single day in the UK, though it is important to note that background levels vary depending on your specific location. |
When to Postpone or Skip a Scan?
Although the radiation dose is very small, Scanletics follows established safety protocols in line with clinical best practice, and certain circumstances may mean a scan needs to be postponed or is not suitable.
Pregnancy. If you are currently pregnant or believe you may be pregnant, you should not undergo a DEXA scan. Although the dose is very small, the general consensus among clinical guidelines is to discourage elective X-ray exposure during pregnancy to prevent harm to the developing foetus. Current guidance generally does not identify DEXA scanning as a concern in relation to breast milk. However, it is advisable to discuss this with your clinician or imaging provider if you have any questions.
Recent Medical Imaging with Contrast. If you have recently had a medical procedure that utilised contrast medium (for example, a barium swallow or some types of CT scans), you should wait a minimum of 7 to 14 days after the procedure before scheduling your DEXA scan. The contrast medium can remain in the body for a short time and potentially influence the accuracy of your body composition results.
Mobility and Weight Limits. Due to the weight limitation of the scanner (usually around 200 kg, but this varies based on the specific machine), and the requirement for individuals to lie flat on their backs for a few minutes, if you have significant mobility restrictions, please contact us prior to booking your scan.
What to Expect on the Day of Your Scan?
One of the main reasons DEXA is a preferred tool for athletes and health enthusiasts is that it is entirely non-invasive.
PREPARATION Eating: Avoid eating (or eat very little) for four hours before your scan. Exercise: Limit physical exertion prior to your appointment. Muscles should not be "pumped up," and your breathing should be relaxed. Hydration: Try to maintain normal, consistent hydration levels. | WHAT TO WEAR We ask that you wear comfortable, loose-fitting clothes without metal zippers, underwire bras, or buttons. | THE DURATION The scan itself is fast, usually taking between 5 to 10 minutes. Including the time to discuss your goals and review the data, most appointments are finished within half an hour. |
THE PROCESS Lie flat on an open, padded bed as a “scanner arm” gradually passes over your body. The procedure is non-invasive and comfortable. Please follow the preparation guidance above regarding food, exercise, and hydration before your appointment. |
Safety and Preparation Checklist
Before arriving at a Scanletics clinic, keep these points in mind:
Pregnancy: Confirm you are not pregnant before booking.
Contrast scans: Ensure a 14-day gap since any barium- or Iodine-based medical tests.
Clothing: Choose gym gear without metal elements for the most accurate reading.
Medical hardware: If you have a pacemaker, joint replacement, or other medical implant, please inform your technician before the scan. This allows them to account for how the hardware may affect readings and to advise you appropriately.
Data You Can Trust
Is a DEXA scan suitable for you? For most healthy adults, a DEXA scan can offer useful data on body composition and bone health, while involving a radiation dose that is generally considered very low in the context of medical imaging.
Your Next Steps To schedule a DEXA scan for a clinical assessment of your body composition body composition, please review our available appointment times. → New to DEXA? Try using our body recomposition calculator as a starting point for finding your targets. → Book a Scan: Every Scanletics appointment includes a 35-minute consultation with an expert to help you turn your data into a clear action plan. View our scan packages and book your appointment today → Sources Shepherd JA, Ng BK, Sommer MJ, Heymsfield SB. Body composition by DXA. Bone. 2017 Nov;104:101-105. doi: 10.1016/j.bone.2017.06.010. Epub 2017 Jun 16. PMID: 28625918; PMCID: PMC5659281. Leeds Teaching Hospitals NHS Trust (2024) Bone density scan (DEXA). Available at: https://www.leedsth.nhs.uk/services/radiology/bone-density-scan-dexa/ (Accessed: 24 March 2026) |
