Can You Get a Flu Shot While on Mounjaro? (October 2026)

01 · The short answer

What to do if you want a flu shot while on Mounjaro

Treat the flu shot as a routine conversation, not a crisis. Book or accept the vaccination, and mention Mounjaro when you do. The clinician giving the vaccine needs to know every medicine you take, including a weekly injectable such as Mounjaro (tirzepatide).¹

Your prescriber knows your dose, your medical history and your other medicines. They are the right person to say whether anything about your situation needs adjusting. If you are an EverydayMeds customer, you can raise it with the prescribing team through your monthly review or our support line.

Do not stop, skip or move your weekly Mounjaro dose on your own because of a vaccination. If you think timing matters for you, ask first and follow the answer you get. Our related guide on having a flu jab on Mounjaro covers the same question from another angle.

02 · Quick reference

Who to ask, and what to ask them

03 · If you are not yet on treatment

Thinking of starting Mounjaro this winter?

Many people ask about vaccines because they are about to start treatment. The Mounjaro pen starts with a 2.5mg pen at a standard price of £169.99 per month. Your first 2.5mg pen costs £129.99 with code FIRST40. Every later order is £25 off the standard price (code DOSE25). All six doses are in stock, and prices were checked 11 October 2026.

Mounjaro is a prescription-only medicine. You start with a free online consultation, and a GPhC-registered prescriber reviews it. You can mention your vaccination plans on the questionnaire, and the prescriber will see them with your other medicines. You can start your free consultation whenever you are ready, or read how to buy Mounjaro in the UK.

04 · Why we cannot give a vaccine rule

Where interactions and precautions are listed

The Mounjaro Summary of Product Characteristics and the patient information leaflet are the documents that list interactions and precautions for the medicine.¹¹³ Both are published on the electronic medicines compendium and are free to read. If you want to check for yourself, search for the Mounjaro KwikPen entry and read the sections on interactions and special warnings.

The vaccine has its own leaflet too. Between the two documents and a conversation with a clinician, you have a better answer than a forum thread or a summary written by a search engine.

A quick check with a professional who knows your history is quicker than it sounds, and it covers you in a way a general web answer cannot.

05 · What Mounjaro is

What Mounjaro is, in brief

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. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

That detail helps when you speak to a vaccinator. "I take a weekly tirzepatide injection, currently at 7.5mg, last injected on Sunday" is far more useful than "I'm on a weight loss jab". Clinicians record medicines by name and dose.

06 · How the medicine works

How Mounjaro works, and why it matters for appointments

Tirzepatide activates two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹ In practice, most people feel fuller sooner and less hungry between meals.

The leaflet and your prescriber are where its precautions are listed. One practical point for vaccination day: if you are eating less than usual around an appointment, mention it.

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4–5 weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹ It also means skipping one weekly dose does not remove the medicine from your body overnight, so any decision to skip should still be made with your prescriber, not on your own.

07 · Flu symptoms and Mounjaro

Flu-like symptoms: vaccine, illness or medicine?

If you feel rough after a vaccination, it is natural to wonder what caused it. The leaflet for the vaccine you were given is the right place to look, along with the NHS pages on flu vaccination.

It is also common to confuse illness, vaccine reactions and medicine side effects. Our separate article on flu-like symptoms from Mounjaro covers the symptom question directly. If something is new, worsening or worrying, contact a clinician. For anything urgent, call 111 or 999.

You can also report a suspected side effect of any medicine or vaccine through the MHRA Yellow Card scheme.¹⁹ Reports help regulators spot patterns. You do not need to be certain of the cause to report.

08 · Being ill with flu while on treatment

If you catch flu while on Mounjaro

If you already have flu, speak to your prescriber before your next injection.

Flu can also reduce appetite, which is why people often ask whether the two overlap; our article on whether flu suppresses appetite looks at that. When you are unwell and eating little, tell your prescriber so they can advise you on your actual situation.

Keep a note of your symptoms, your temperature if you have taken it, and when your last injection was. This makes a call or message to your prescriber much faster.

09 · Other procedures and appointments

Vaccines are not the only appointment to mention

The same habit applies to any treatment while on Mounjaro: tell the person treating you. That includes dentists, aesthetic clinics, surgeons and anyone who might give you a medicine or sedation. Our article on having Botox while on Mounjaro is one example, and our guide to life while on Mounjaro collects others.

If you use the oral contraceptive pill, discuss this with your prescriber. The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹ Doses of insulin or sulfonylureas may also need adjusting because of the risk of low blood sugar.¹

These are examples of why a full medicines list matters.

10 · NHS and private access

NHS and private routes

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 (initially BMI 40+ with four or more qualifying conditions).⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

Whichever route you use, flu vaccination is usually arranged separately through your GP surgery, a community pharmacy or an NHS vaccination service. Tell them about your Mounjaro whether it is supplied through the NHS or privately.

11 · Who prescribes and reviews

How EverydayMeds handles questions like this

EverydayMeds is a GPhC-registered UK online pharmacy (registration 9012878). Mounjaro is supplied through official LillyDirect supply, so you receive genuine KwikPens from Eli Lilly's UK distribution. Every order follows a free online consultation reviewed by a GPhC-registered prescriber, not a scoring script.

Ongoing monthly reviews are part of the service, along with dose titration, follow-up assessments and side-effect support. If you are planning a vaccination, a procedure or a holiday, raise it in your review. Support is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, through the account portal chat or by phone on 0333 207 0413.

Orders placed by 3pm are dispatched the same day, with free next-day tracked delivery in temperature-controlled packaging. If you are thinking about how to get the last shot of Mounjaro, or how to plan your supply around other commitments, our team can talk it through. For a wider view, see all weight loss treatments.

Mounjaro is a prescription-only medicine, used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice.

12 · 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