Can Mounjaro Cause DVT? What the UK Evidence Says (October 2026)

01 · The core answer

Is DVT a side effect of Mounjaro?

No. Deep vein thrombosis is not listed as a side effect in the UK product information for Mounjaro, which is the document prescribers rely on.¹¹³

That is different from saying a clot could never happen to someone who takes it. People who use Mounjaro are a large group of adults, and clots can occur in any large group of adults for reasons unrelated to the treatment.

If you have symptoms of a clot while on Mounjaro, get medical help straight away, whatever the cause.

02 · Your next step

What should I do if I am worried?

If you have a swollen, painful or warm leg, or sudden breathlessness or chest pain, get medical help straight away. Do not wait for your next scheduled review, and do not wait to see whether it settles.

If you are worried but have no symptoms, tell your prescriber about your clot history before you start or continue. Your prescriber can take your full history into account. You can read more in our dedicated guide to Mounjaro and DVT.

If you are still deciding whether treatment is right for you, our weight loss clinic explains how a consultation works. The free consultation is reviewed by a GPhC-registered prescriber, who will ask about your medical history, including any previous clots.

Related guides: Can mounjaro cause sleepless nights and Does mounjaro cause aggression.

03 · What the label says

What the UK product information says

The SmPC is the regulator-approved record of how a medicine should be used and what reactions are known.¹ The patient information leaflet is the plain-English version for people taking it.¹³ Neither lists deep vein thrombosis as a side effect of Mounjaro.

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes.¹

If you notice something that is not in the leaflet, that does not mean it is unimportant. It means it needs reporting. The Yellow Card scheme exists so that unlisted possible reactions are collected and assessed.¹⁹

04 · Why the question comes up

Why people ask about clots and weight-loss injections

People ask because clots are serious and because Mounjaro is a newer, widely discussed medicine. When a medicine is taken by many people, some will have a clot at some point for reasons that have nothing to do with it. Timing alone does not show cause.

Many of the people who consider treatment have a higher body weight, and that is part of why they are considering it. Health conditions and daily circumstances can affect clot risk in anyone, and your prescriber is the right person to talk these through with you.

Treatment is licensed alongside a reduced-calorie diet and increased physical activity.² Staying active is part of how the medicine is meant to be used, not something to drop while you lose weight.

05 · Other causes of DVT

What can cause sudden DVT, and which medicines raise risk?

In general terms, clots are linked with things such as recent surgery, long periods of immobility, past clots, and some other medicines or conditions. Your GP or prescriber can tell you which apply to you.

For that reason, a medicines question is best answered with your own list. If you take hormone-based medicines, blood thinners or anything else prescribed for a circulation problem, say so at your consultation and at every review.

This matters for another practical reason. Your prescriber needs the full picture to decide whether Mounjaro is appropriate for you. A short, honest medical history is the single most useful thing you can bring.

06 · Symptoms to act on

Symptoms that need urgent attention

A swollen, painful or warm leg that appeared without a clear reason needs medical help straight away. Sudden breathlessness or chest pain, especially together with a sore leg, also needs medical help straight away.

These symptoms can have causes other than a clot, and many do. You cannot tell the difference at home, which is exactly why they should be checked quickly. Call 999 or go to A&E, or use NHS urgent care.

Not every leg symptom is a clot. Our guide on Mounjaro and breathlessness covers why breathing symptoms should be assessed, and our Raynaud's page covers a different circulation-related query. If a symptom is new, severe or getting worse, treat it as a medical question first.

After you have been assessed, tell the clinician you take Mounjaro, and tell your prescriber what you were told. That keeps your records complete and lets the prescribing team review your treatment properly.

07 · Safe use and reporting

Using Mounjaro safely and reporting concerns

Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. Individual results vary.

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system.¹ There is no way to speed this up, and nothing needs doing while it clears.

To report a suspected side effect, use the MHRA Yellow Card scheme. You can report a symptom even if you are not sure the medicine caused it.¹⁹ Reports help regulators spot patterns that individual patients and clinicians cannot see.

Our aftercare includes ongoing monthly reviews, dose-titration and follow-up assessments by the prescribing team, plus side-effect support. Repeat orders re-check suitability, and there is no auto-shipping. If your health changes between orders, say so.

NHS access is also relevant if you are weighing options. Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first.⁴⁶ Many people who meet the licensed criteria choose regulated private treatment rather than waiting.

08 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹