The official documents
Each product information document was checked on 20 October 2026. None lists DVT, pulmonary embolism or venous thromboembolism (VTE, the umbrella term for both) as an adverse reaction, in trial tables or in post-marketing reports.
| Document | DVT, PE or VTE | Nearest relevant content |
|---|---|---|
| US Prescribing Information, revised 05/2026 [1] | Not listed in section 6.1 or 6.2 | Section 5.6 warns about dehydration after stomach side effects |
| EU summary of product characteristics, section 4.8 [2] | Not listed | Section 4.4 asks people to avoid fluid depletion |
| Canadian monograph, authorised 2026-07-13 [3] | Not listed | Post-market reports include dehydration |
Two meta-analyses, two answers
A meta-analysis in the Journal of the American Heart Association pooled 39 randomised trials with 70,499 participants, comparing GLP-1 medicines with placebo or other diabetes drugs. Overall VTE showed a non-significant upward trend (odds ratio 1.19), but DVT on its own was significantly more frequent (odds ratio 1.64), about 25 extra events per 10,000 person-years. The excess was most marked in trials lasting longer than 18 months and in cardiovascular outcome trials, and there was no significant change in PE [4].
A meta-analysis in the Journal of Thrombosis and Haemostasis took 27 placebo-controlled trials with 84,003 patients. It found no significant difference in overall VTE (risk ratio 0.70), no significant difference in DVT (risk ratio 1.21) and a lower risk of PE (risk ratio 0.60). Median VTE rates were 1.1 per 1,000 patient-years on GLP-1 medicines and 2.5 on placebo [5].
Why the results differ and what they mean for Ozempic®
The two analyses used different sets of trials (one included active comparators, the other placebo only), different statistical models and different cut-off dates. Clots were rare in both, so a handful of events can move the result. Both pooled several GLP-1 medicines, including but not limited to semaglutide, so neither gives an Ozempic®-specific estimate.
Observational data add another angle. A 2025 Nature Medicine analysis of US veterans with diabetes found GLP-1 use associated with a lower risk of coagulation disorders compared with usual care [6]. Single case reports also exist, such as a woman with type 2 diabetes who developed a portal vein clot within six months of starting semaglutide and was later found to carry a gene change linked to clotting [7]. One case cannot show cause.
Possible links, and what is only proposed
From the label: Ozempic® can cause vomiting and diarrhoea, and section 5.6 links these to dehydration [1]. Cleveland Clinic lists drinking enough fluids, especially when travelling, among ways to prevent DVT [9]. Whether dehydration on Ozempic® raises clot risk has not been studied.
Proposed but unconfirmed: the JTH authors note that earlier observational data had suggested GLP-1 medicines might lower VTE risk, an effect their analysis of randomised trials did not confirm for VTE overall [5].
General background: clots form when blood flow slows, a vein is injured or the blood clots more readily, and the risk rises when several factors coincide [8].
Risk factors that matter for everyone
The CDC, Cleveland Clinic and MedlinePlus list the main risk factors for DVT and PE [8][9][10]:
- Major surgery, especially of the abdomen, pelvis, hip or legs, fractures and severe muscle injury.
- Long periods without moving: bed rest, a leg in a cast, or sitting for hours on a journey.
- Oestrogen from contraceptives or hormone therapy, pregnancy and the months after giving birth.
- Heart or lung disease, cancer and its treatment, and inflammatory bowel disease.
- A previous clot, an inherited clotting disorder or a family history of clots.
- Older age, overweight or obesity, and smoking.
What general sources suggest
Cleveland Clinic’s prevention advice is practical: move around as soon as you can after illness or surgery, exercise your calf muscles and get up regularly on long journeys, drink enough fluids at all times, use medicines or compression stockings after surgery if your provider prescribes them, and avoid tobacco [9]. CDC notes that risk climbs when several factors are present together, which is a reason to tell your care team about all of them before surgery or long travel [8].
None of these sources mentions Ozempic®. If you are planning surgery, the Ozempic® label separately asks you to tell your healthcare providers in advance because of a rare risk of inhaling stomach contents under deep sedation [1].
Ozempic® context
Ozempic® is a once-weekly injection approved for adults with type 2 diabetes; its label starts at 0.25 mg and increases in steps of at least four weeks [1]. Some of the trials in the meta-analyses above were cardiovascular outcome trials in people with diabetes and heart disease, a group that already carries a higher baseline risk, since heart disease is itself a clot risk factor [4][8]. If you have had a clot before, or take oestrogen, mention it when Ozempic® is being considered so your prescriber has the full picture.
Ozempic® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Sudden shortness of breath, chest pain, coughing up blood, light-headedness or fainting | Emergency services; these can be signs of a pulmonary embolism | Emergency | Cleveland Clinic [9] |
| Swelling of one leg or arm, with pain, warmth or red or discoloured skin | Your provider right away or the emergency room | Emergency | Cleveland Clinic [9], MedlinePlus [10] |
| A sudden severe headache with vision changes, stroke-like symptoms or seizures | Emergency services | Emergency | Cleveland Clinic [9] |
| Swelling of the legs, ankles or feet, or passing less urine | Your doctor immediately, or emergency care | Emergency | MedlinePlus semaglutide page [11] |
| Vomiting or diarrhoea that does not stop | Your prescriber, because of the dehydration warning | Today | Ozempic® Medication Guide [1] |
| A past clot, a clotting disorder, or oestrogen use, before starting Ozempic® or before surgery | Your prescriber and surgical team | At your next appointment | CDC [8], Ozempic® label section 5.10 [1] |
