Blood clots are not listed as a side effect or a warning on the Zepbound or Mounjaro label. The trials that back the label did not report clots as a common event either. In SURPASS-4, a trial in adults with type 2 diabetes and high heart risk, tirzepatide did not raise the rate of major heart and vessel events. That does not mean a clot can never happen to someone on the drug. It means the drug is not a known cause. Start with our tirzepatide guide if you are new to the drug.
Key takeaways
- Neither label lists blood clots, deep vein thrombosis, pulmonary embolism or stroke as an adverse reaction or warning.
- SURPASS-4 compared tirzepatide with insulin glargine in people with type 2 diabetes and high cardiovascular risk and found no increase in major adverse cardiovascular events.
- The label does warn about dehydration from vomiting and diarrhea, which is a general risk factor for clots in anyone.
- Clot signs, such as a swollen painful leg or sudden chest pain and shortness of breath, need urgent care no matter what medicine you take.
- Compounded tirzepatide is the same molecule and carries the same label facts. It is not FDA approved.
Does tirzepatide cause blood clots? What the label says
The label has a long list of warnings. Clots are not on it. Here is how the heart and blood vessel topics people ask about line up with the label text.
| Topic | On the label? | What the label says |
|---|---|---|
| Blood clots (DVT, pulmonary embolism) | No | Not listed as an adverse reaction or a warning |
| Stroke or heart attack | No warning | Not listed as a warning; SURPASS-4 found no increase in major adverse cardiovascular events |
| Dehydration and acute kidney injury | Yes | Warning: fluid loss from vomiting or diarrhea can injure the kidneys |
| Hypersensitivity reactions | Yes | Warning: allergic reactions, including serious ones |
| Injection site reactions | Yes | Common adverse reaction: redness, itching or a bump at the shot site |
Source: Zepbound and Mounjaro labels, Adverse Reactions and Warnings and Precautions sections (DailyMed); SURPASS-4 (PubMed 34672967).
What SURPASS-4 found about heart and vessel events
SURPASS-4 is the trial to know here. It compared tirzepatide with insulin glargine in adults with type 2 diabetes who already had high cardiovascular risk. That is the group where you would expect to see a clot or heart signal if there were one. The published result: no increase in major adverse cardiovascular events with tirzepatide. Major adverse cardiovascular events means heart attack, stroke and cardiovascular death. The trial did not set out to study leg clots or lung clots on their own, so it cannot say "zero clots." It can say the drug did not push the big heart and vessel events up.
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People connect tirzepatide and blood clots for a few reasons. None of them is a label finding, so treat each as a possibility, not a fact.
| Reason people worry | What is actually known |
|---|---|
| Dehydration | The label warns about fluid loss from vomiting and diarrhea. Being dehydrated is a general clot risk factor for anyone. Drink fluids and treat gut symptoms early. |
| A red, sore bump at the injection site | Injection site reactions are a listed common adverse reaction. They are skin reactions, not clots in a vein. |
| Leg cramps or aches | Not on the label. Low fluid and low intake are the plausible causes. A cramp comes and goes; a clot causes steady swelling and pain in one leg. |
| Fast heartbeat | Palpitations are not on the label's common list. A small rise in resting heart rate is a known class observation, but the label does not tie it to clots. |
| Birth control pills | The label says tirzepatide may reduce absorption of the pill. That is about pregnancy risk, not clot risk. |
Source: Zepbound and Mounjaro labels (DailyMed). "Not on the label" means the item does not appear in the Adverse Reactions or Warnings sections.
Blood clot warning signs: when to seek urgent care
These signs apply to everyone, on tirzepatide or not. Do not wait to see if they pass.
| Where | Signs | What to do |
|---|---|---|
| Leg (deep vein thrombosis) | Swelling, pain or tenderness in one leg, often the calf; warmth or redness of the skin | Same-day medical care |
| Lung (pulmonary embolism) | Sudden shortness of breath, sharp chest pain that is worse when you breathe in, fast heartbeat, coughing up blood | Call emergency services |
| Brain (stroke) | Face drooping on one side, arm weakness, slurred or confused speech, sudden severe headache | Call emergency services |
| Heart (heart attack) | Chest pressure or pain, pain spreading to the arm, jaw or back, sweating, nausea with chest discomfort | Call emergency services |
Source: general emergency warning signs; these are not tirzepatide label text and are listed so readers know when to seek care.
Tirzepatide and blood clots if you already have a clotting history
The label does not carry a contraindication or a warning for people with a past clot. It also does not say the drug is safe for them. That is a gap, and your prescriber has to fill it with your history. If you take a blood thinner, the label's general note about oral drugs applies: tirzepatide slows the stomach and may change how oral medicines are absorbed. Warfarin and the newer oral blood thinners are not named on the label, but a pharmacist should know you take one. See our page on tirzepatide drug interactions.
What this means for compounded tirzepatide
Compounded tirzepatide contains the same active molecule, so the same facts apply: no clot warning on the label, and no trial of the compounded product itself. It is not FDA approved and is not interchangeable with Zepbound or Mounjaro. FormBlends prescriptions are written by independent, state-licensed clinicians of Recess MD LLC. If you have had a clot, say so in the assessment; the clinician decides. You can start an assessment or see pricing first.
Frequently Asked Questions
Does tirzepatide cause blood clots?
Blood clots are not listed as an adverse reaction or a warning on the Zepbound or Mounjaro label. SURPASS-4 found no increase in major adverse cardiovascular events with tirzepatide. The drug is not a known cause of clots.
Can tirzepatide cause blood clots through dehydration?
The label warns about fluid loss from vomiting and diarrhea because it can injure the kidneys. Dehydration is a general risk factor for clots in anyone. That is a reason to keep drinking fluids and to call your prescriber if you cannot keep them down, not a label finding that the drug causes clots.
Does Zepbound cause heart issues?
The Zepbound label does not carry a heart attack or stroke warning. In SURPASS-4, a trial in adults with type 2 diabetes and high heart risk, tirzepatide did not increase major adverse cardiovascular events. Palpitations are not listed among the common adverse reactions.
What are the signs of a blood clot I should watch for?
One swollen, painful leg; sudden shortness of breath or chest pain; face drooping, arm weakness or slurred speech. These need urgent care whether or not you take tirzepatide.
Can I take tirzepatide if I have had a clot before?
The label does not forbid it and does not address it. Your prescriber has to weigh your history and any blood thinner you take. Tell the tirzepatide prescriber and your pharmacist.
Sources
- Zepbound (tirzepatide) prescribing information, DailyMed, Eli Lilly, revised 08/2026.
- Mounjaro (tirzepatide) prescribing information, DailyMed, Eli Lilly, revised 08/2026.
- Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4), Del Prato et al., The Lancet, 2021.
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1), Jastreboff et al., New England Journal of Medicine, 2022.
Next steps
Read the complete tirzepatide side effects guide and our page on tirzepatide and heart palpitations. Browse the tirzepatide hub for every other tirzepatide question. Talk to a licensed clinician about your heart and clotting history before you start. Compounded tirzepatide is not FDA approved and is not interchangeable with Zepbound or Mounjaro; a licensed provider decides whether it is appropriate for you.
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