Ozempic and bone density, in brief: the trial evidence is small and not settled. In the main placebo-controlled trial, 64 adults at higher fracture risk took semaglutide 1 mg (the active drug in Ozempic) for 52 weeks. Their hip and spine bone density ended slightly lower than with placebo, and a bone-breakdown marker was higher.[1] The Wegovy label also reports more hip and pelvis fractures with semaglutide in women and in people 75 and older in its heart trial.[3] Larger reviews have not found a consistent effect on bone density or fractures, and weight loss appears to explain much of the change.[7]
This review covers what trials actually measured, what the labels say, and who should talk to a clinician about bone health. For the drug itself, see our semaglutide profile.
Why weight loss can affect bone
Bone adapts to the load it carries. When people lose a lot of weight by any method, including dieting and bariatric surgery, bone turnover rises and bone density tends to fall.[9] A 2025 review of GLP-1 drugs in obesity found early signs of a slight drop in bone density and more bone remodeling favoring breakdown, similar to calorie restriction. It also called the evidence limited.[9] The open question is whether semaglutide affects bone beyond what the weight loss alone would do.
The key semaglutide trial
| Detail | Finding |
|---|---|
| Who | 64 adults (86% postmenopausal women), mean age 63, with low bone density or a recent low-energy fracture |
| Treatment | Semaglutide 1.0 mg weekly or placebo for 52 weeks |
| Primary result | No change in the bone-formation marker P1NP |
| Bone breakdown | The resorption marker CTX was higher on semaglutide |
| Bone density | Lower on semaglutide at the lumbar spine (−0.018) and total hip (−0.020); no difference at the femoral neck |
| Weight | 6.8 kg lower on semaglutide than placebo |
Source: Hansen and colleagues, 2024.[1] Bone density differences are in g/cm².
The trial was designed to test whether semaglutide would boost bone formation, as earlier studies had suggested. It did not.[1] The authors said the rise in bone breakdown may be explained by the weight loss. It was not designed to measure fractures.
Smaller semaglutide studies
- Older adults (pilot, 20 weeks): 20 adults averaging 73 years old got semaglutide 1 mg plus lifestyle counseling or counseling alone. Whole-body bone density did not differ significantly between groups. The numbers trended toward lower density and higher turnover with semaglutide, and the authors called for larger studies.[2]
- Oral semaglutide (52 weeks, no control group): in 36 adults with type 2 diabetes and obesity, high-resolution scans of the wrist and shin suggested stable or slightly higher volumetric bone density despite weight loss. Without a placebo group, this cannot show cause and effect.[6]
- Clinic records (semaglutide or tirzepatide): 255 users were compared with 255 matched non-users over a median of 17 months. Both groups lost hip bone density at similar rates overall. In people without diabetes, hip bone loss was greater on the drugs (−1% vs −0.6% a year), and more weight loss went with more bone loss.[5]
Fracture data from the Wegovy label
Ozempic’s label does not include a bone or fracture warning.[10] The Wegovy label, which uses higher semaglutide doses, reports fractures from two large trials:[3]
| Trial and group | Wegovy | Placebo |
|---|---|---|
| SELECT heart trial, women: hip and pelvis fractures | 1% (24 of 2,448) | 0.2% (5 of 2,424) |
| SELECT heart trial, age 75 and older: hip and pelvis fractures | 2.4% (17 of 703) | 0.6% (4 of 663) |
| MASH (fatty liver) trial: any fracture | 4.4% | 3.3% |
These numbers come from the label’s adverse reaction section, and the label does not say why the fractures happened. It also notes that people 75 and older, on Wegovy or placebo, reported more serious adverse reactions overall than younger patients.[3]
What the pooled evidence says
- A 2026 meta-analysis of 60 studies (46 randomized trials) across several GLP-1 drugs found no effect on bone density or fractures when using the most adjusted estimates. It did find consistent loss of lean mass, mostly with liraglutide and semaglutide. The certainty of the evidence was rated low.[7]
- A 2025 meta-analysis of 44 diabetes trials with 47,823 people found fewer fractures with GLP-1 drugs overall (relative risk 0.77). The benefit was seen with liraglutide but not clearly with other GLP-1 drugs, and fractures were rare (292 in total).[8]
Most of these trials enrolled people with diabetes, used lower doses, and were not designed to study bone. That limits how well they apply to semaglutide 2.4 mg for weight loss.
Exercise may matter
The best evidence on protecting bone comes from liraglutide, an older daily GLP-1. In a 52-week trial, 195 adults with obesity first lost weight on a low-calorie diet. They were then randomized to exercise, liraglutide 3 mg, both, or placebo. With liraglutide alone, hip and spine bone density fell more than with exercise alone, despite similar weight loss. With the combination, bone density was similar to placebo while weight loss was greatest.[4] No equivalent trial has been published for semaglutide.
Muscle loss raises fall risk too. Our guide to GLP-1 muscle loss covers strategies to protect lean mass.
Trials still under way
A Danish trial, SOBER II, is testing oral semaglutide against placebo for 52 weeks in 64 adults aged 50 to 85 with type 2 diabetes and higher fracture risk. It uses bone markers, scans, biopsies and direct bone-strength testing, with primary completion listed for January 2027.[11]
How this applies to Ozempic doses
Ozempic is dosed at 0.5 mg, 1 mg or 2 mg once weekly for type 2 diabetes, with 2 mg the maximum.[10] The main bone-density trial used 1 mg, a common Ozempic dose.[1] The fracture findings above come from Wegovy trials, where the usual maintenance dose is higher, at 2.4 mg weekly.[3] It is not known whether bone effects differ by dose, because no trial has compared doses for bone outcomes. The trials also differ in design. The 1 mg trial chose people at higher fracture risk and followed them for a year. The Wegovy heart trial followed about 8,800 people per group for a median of just over 3 years and collected only serious adverse events and certain other events.[3]
Who should ask about bone health
There are no bone-specific dosing rules in the Ozempic or Wegovy labels.[3][10] It is reasonable to raise bone health with your clinician if you:
- Are a postmenopausal woman or aged 75 or older
- Have osteoporosis, low bone density or a past fragility fracture
- Expect to lose a large amount of weight
Your clinician may consider a DXA scan, calcium and vitamin D intake, and strength training.
Questions to ask your clinician
- Do my age and history put me at risk of fractures on semaglutide?
- Should I have a bone density scan before or during treatment?
- What exercise is safe for me to protect bone and muscle?
- Is my weight loss pace reasonable, or should we slow the dose increases?
For results and dosing context, see semaglutide weight loss results, the semaglutide dosage chart and Wegovy vs Ozempic.
