Can You Give Blood on Mounjaro
, by Andrew Odgers, 9 min reading time
Eligibility
Can you give blood on Mounjaro?
Mounjaro (tirzepatide) is not listed on the NHS permanent deferral list, which means it does not automatically prevent you from giving blood. You should declare it on the health questionnaire at your appointment and the clinical team will confirm your eligibility on the day. As a relatively new medication, guidance on GLP-1 and GIP receptor agonists continues to evolve. If you want to confirm your position before attending, the NHS donor helpline at 0300 123 23 23 can provide the most current advice.
What Mounjaro is and how it works
Mounjaro, tirzepatide and blood donation eligibility
What Mounjaro is prescribed for
Mounjaro is the brand name for tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. It is licensed in the UK for the management of type 2 diabetes and, more recently, for weight management in people with obesity. It is administered by weekly subcutaneous injection using a pre-filled pen.
Tirzepatide works by mimicking two gut hormones that regulate appetite, gastric emptying and blood glucose. It reduces appetite, slows the rate at which the stomach empties and stimulates insulin release in a glucose-dependent manner. The result is improved blood sugar control and, for many patients, significant weight loss.
Why Mounjaro is not on the deferral list
NHS Blood and Transplant maintains a medication deferral list that is updated as new drugs come to market and as clinical evidence accumulates. Tirzepatide is not currently included on this list as a reason for automatic deferral. The drug does not affect haemoglobin levels directly, does not impair blood clotting, and is not associated with any blood-borne risk to recipients.
This does not mean the position is guaranteed to remain unchanged. Guidance on newer medications can be revised as post-marketing evidence develops. Checking the NHS medication tool at blood.co.uk before each appointment is good practice for anyone on a recently introduced drug.
The underlying condition may also be relevant
Mounjaro is prescribed for type 2 diabetes or obesity. The condition being treated can independently affect your eligibility. People with type 2 diabetes managed with any medication, including injectable GLP-1 or dual agonist treatments, are generally eligible to donate provided their condition is well controlled and they feel well on the day.
Your haemoglobin will be checked at every appointment regardless of the medications you are on. Eating a full meal two to three hours before your appointment and drinking extra water on the day gives you the best chance of a successful haemoglobin reading.
Side effects and fitness to donate on the day
Mounjaro commonly causes gastrointestinal side effects, particularly when first starting treatment or after a dose increase. These include nausea, vomiting, diarrhoea, reduced appetite and fatigue. The NHS requirement to feel well on the day of donation means that if you are experiencing any of these side effects at the time of your appointment, you should reschedule.
If you have been on a stable dose for several weeks and are no longer experiencing significant side effects, donation is likely to proceed without difficulty. The timing of your appointment relative to your weekly injection is worth considering: some donors find that booking their appointment mid-week, a few days after their injection day, avoids the window when side effects are most likely.
Ozempic, Wegovy and similar medications
Semaglutide medications, including Ozempic for diabetes and Wegovy for weight management, are in the same drug class as Mounjaro. Neither is on the NHS automatic deferral list. Both require declaration and individual assessment at your appointment, following the same approach as tirzepatide.
Liraglutide (Victoza for diabetes, Saxenda for weight management) is an older GLP-1 receptor agonist in the same family and is treated identically. If you take any medication in this class, declare it on your questionnaire and let the clinical team confirm your eligibility on the day.
Ready to donate
Taking Mounjaro and want to donate?
Declare your medication at the appointment and the clinical team will assess your eligibility on the day. Many donors on GLP-1 and GIP receptor agonists give blood successfully. Book your appointment now.
When to check before attending
Situations where calling the helpline first makes sense
Mounjaro does not automatically prevent donation, but contact the NHS donor helpline on 0300 123 23 23 before your appointment if any of the following apply.
- You recently started Mounjaro or have just had a dose increase. Side effects are most pronounced in the first few weeks. Allow time for your body to adjust before donating.
- You are experiencing active nausea, vomiting or significant fatigue from the medication. The NHS requires you to feel well on the day. Reschedule until side effects have settled.
- Your diabetes management has changed significantly since starting Mounjaro. Allow blood sugar levels time to stabilise on the new regimen before adding the mild physiological demand of donation.
- You are on Mounjaro alongside other medications you are uncertain about. The helpline can assess your full medication list together rather than in isolation.
Mounjaro is one of a new generation of highly effective weight and diabetes medications that many donors are now taking. The NHS donation service keeps its guidance current as new drugs become established. Declare the medication honestly, feel well on the day, and the clinical team will guide you through the rest.
Our Can you give blood if you are on medication guide covers the full medication eligibility picture, including which drugs prevent donation and which do not.
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This article is part of our complete giving blood knowledge base, covering eligibility, preparation, what happens on the day, recovery, types of donation and the science of why blood is so urgently needed.
Keep reading
Medication, diabetes and eligibility guides
Can you give blood if you are on medication covers the complete medication eligibility framework. Can diabetics give blood covers eligibility for donors managing diabetes. And Can I give blood covers the full eligibility picture.
Frequently asked
Mounjaro and blood donation questions
Is Mounjaro on the NHS blood donation deferral list?
As of 2026, tirzepatide is not on the NHS Blood and Transplant permanent deferral list. Declaration and individual assessment at your appointment are required, but there is no automatic ban on donating while taking Mounjaro.
Can I give blood the same day as my weekly Mounjaro injection?
It is sensible to avoid donating on the same day as your injection if you find that day causes any nausea or fatigue. Booking your appointment mid-week, a few days after your injection, typically avoids the window when side effects are most likely.
Does Mounjaro affect haemoglobin levels?
Not directly. Mounjaro affects blood glucose and appetite hormones but does not directly alter haemoglobin concentration. Your haemoglobin will be checked at your appointment in the standard way.
Can I give blood on Ozempic or Wegovy?
Neither semaglutide medication is on the automatic deferral list. Both require declaration and individual assessment at your appointment. The approach is identical to Mounjaro.
What if I feel nauseous from Mounjaro on donation day?
Reschedule your appointment. The NHS requires you to feel well on the day of donation regardless of the cause of any unwellness. Nausea from Mounjaro is a valid reason to postpone, and there is no penalty for doing so.
Will guidance on Mounjaro and donation change?
It may. Guidance on newer medications is reviewed as post-marketing evidence accumulates. Checking the NHS medication tool at blood.co.uk before each appointment ensures you have the most current position.