Mounjaro and Nasal Congestion (October 2026)

01 · Core answer

Is your blocked nose caused by Mounjaro?

Nasal congestion is not listed as a side effect in the UK Mounjaro patient leaflet.¹³ Tell your prescriber about any new or lasting symptom, and you can report suspected side effects through the MHRA Yellow Card scheme.

Two things are worth separating. First, a symptom that begins while you are on a medicine is not necessarily caused by it. Second, a symptom that is not listed can still be worth reporting, because that is how regulators learn about new signals.

02 · Your decision

What to do if you have a stuffy nose on Mounjaro

Start by noting when it began, whether it comes and goes, and whether you have other symptoms such as sneezing, itchy eyes, a sore throat or a temperature. This helps a pharmacist or prescriber separate a cold or allergy from something that needs a closer look.

Do not stop your injections or change your dose because of a blocked nose alone. If you are worried, speak to the prescribing team or your pharmacist first. If you order through us, our team provides side-effect support and ongoing reviews, so you can raise it at your next check-in or contact support sooner.

Before reaching for a nasal spray, decongestant or antihistamine, ask a pharmacist whether it suits you. Tell them you use Mounjaro and any other medicines you take.

03 · Safety

When a blocked nose needs prompt attention

Get medical help straight away if congestion comes with difficulty breathing, swelling of the face, lips or tongue, a rash that spreads quickly, or if you feel generally very unwell. These are not signs to wait out or manage at home. Call 111 or 999 as appropriate.

See a GP or pharmacist if the stuffiness lasts a long time, keeps returning, disturbs your sleep, or comes with facial pain, a fever or discoloured discharge. Persistent one-sided blockage or nosebleeds also deserve a proper look. None of this is specific to Mounjaro, but you should mention the medicine so that whoever assesses you has the full picture.

If you have any suspected side effect, including one not in the leaflet, you can report it through the Yellow Card scheme.¹⁹ You can report it yourself, and your report helps build the safety picture for everyone.

Related guides: Mounjaro nasal spray and Glp 1 nasal ring how to use and Mounjaro post nasal drip and Mounjaro photosensitivity and Mounjaro rhabdomyolysis.

04 · How Mounjaro works

How Mounjaro works, and why that matters here

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

Tirzepatide is the first treatment of its kind to activate 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. In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

Notice what is in that description: appetite, stomach emptying and insulin response. The nose does not feature.

Most side effects are digestive: the most common, affecting more than 1 in 10 people, are nausea, diarrhoea, vomiting, constipation and abdominal discomfort. We encourage everyone to read it before starting and again if a new symptom appears. If a symptom is on the list, the leaflet explains what to do.

Why does this matter for a stuffy nose? If you assume it is nothing, you might ignore a symptom that deserves attention. The sensible middle path is to treat the symptom on its own terms, check it against the leaflet, and raise it with a professional if it persists or worries you.

05 · Other causes to consider

Other causes of a blocked nose to consider

A blocked nose has many everyday causes, and most are unrelated to any medicine. The most common are viral colds, seasonal or year-round allergies, irritation from dust, smoke or strong smells, and dry air from central heating. Sinus inflammation can also leave you feeling congested and pressured around the face.

Timing is the trap. Many people start Mounjaro in autumn, winter or spring, when colds and pollen are widespread. A stuffy nose that appears a few weeks into treatment may simply have arrived at the same time. Asking yourself what else changed is a better test than assuming the newest thing in your routine is responsible.

You may also be asking whether excess weight itself plays a part. A GP or pharmacist can look at your history and tell you whether it is relevant to you. If you snore, wake unrefreshed or have broken sleep, mention that too, as it helps a clinician see the whole picture.

Some everyday habits can make congestion feel worse, such as sleeping in a very dry room or being around irritants. Keeping a short symptom diary helps. Write down when the stuffiness is worst, whether it follows your weekly injection day, and what else was happening. If there is a clear pattern linked to the injection day, share that diary with your prescriber. It is the kind of detail that makes a report to the Yellow Card scheme genuinely useful.

Medicines you take for other reasons can sometimes affect the nose, and so can overuse of some over-the-counter nasal products. A pharmacist is well placed to check this. Bring a list of everything you take, including anything bought without a prescription.

If your symptoms look like hay fever, such as sneezing, itchy eyes and a runny nose at predictable times of year, that is usually a clue that the cause is environmental. If they look like a cold, they typically pass without treatment. If they are neither, or they last, get advice rather than guessing.

06 · Antihistamines and Sudafed

Antihistamines, Sudafed and other remedies

Many people ask whether they can take an antihistamine or Sudafed on Mounjaro.

First, tell the pharmacist you are using Mounjaro, a prescription medicine, and name any other medicines or health conditions you have. Decongestants and antihistamines vary in their ingredients, and the right choice depends on your own circumstances, such as blood pressure, heart conditions or other treatments.

Second, read the leaflet that comes with the remedy. Over-the-counter products carry their own warnings, and a pharmacist can interpret them in the context of your health. If you are unsure, ask before you buy rather than after.

Third, remember that many nasal symptoms improve without any medicine. Gentle approaches, such as keeping a comfortable room environment and avoiding known triggers, are low risk.

If you have type 2 diabetes and take insulin or a sulfonylurea alongside Mounjaro, doses of those medicines may need adjusting because of the risk of low blood sugar. That is a separate matter from nasal congestion, but it is a reminder that your prescriber should always know what you take.

Do not double up on products with similar ingredients, and do not use a remedy for longer than its packaging allows. If you reach for treatments repeatedly because the stuffiness will not go away, that is itself a reason to speak to a GP rather than keep self-treating.

Lastly, never skip or change your Mounjaro injection to make room for another medicine. If you think there might be a conflict, contact the prescribing team first. Our support team is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk or by phone on 0333 207 0413.

07 · Reporting and reading the leaflet

Reporting a symptom and reading the leaflet

The SmPC and the patient information leaflet are the two reference documents for what is and is not an established side effect.¹¹³ The SmPC is written for healthcare professionals and the leaflet for patients. Both list the recognised effects, ordered by how common they are. Nasal congestion does not appear among them.

That does not mean your experience is invalid. People notice things, and regulators rely on reports to spot patterns that trials may have missed. The Yellow Card scheme, run by the MHRA, lets you or a healthcare professional report a suspected side effect.¹⁹ You do not need proof that the medicine caused the problem. A suspicion is enough.

When you report, it helps to include the dose you were on, when the symptom started in relation to your injections, any other medicines or illnesses at the time, and whether the symptom improved or persisted. Keep the pen batch details if you can.

A single report, or a collection of posts online, cannot show that a medicine causes a symptom. Only careful review of many cases can do that, which is what the regulator does.

Read your leaflet in full when you receive your first pen, and again when you move to a higher strength. Doses are stepped up in stages, and some people notice more effects around those steps. If you are unsure whether something you are experiencing needs attention, the leaflet and your prescriber are the right first stops.

08 · Stopping and clearance

Stopping, skipping and how long Mounjaro stays in your system

If you wonder whether stopping Mounjaro would clear a blocked nose, think about timing first. 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 That means that if you stopped, any effect from the medicine would not disappear overnight.

The right step is to speak to your prescriber, who knows your dose, your progress and your health. Do not take an extra dose to catch up. If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time; if more than 4 days have passed, skip it and take the next one on your normal day.

If you are thinking of stopping because of a symptom, talk it through first. A prescriber can help you decide whether the symptom is likely to be related, whether to adjust the plan, and how to keep going safely with your goals.

If you are on a repeat order with us, we re-check suitability each time, and there is no auto-shipping. That gives you a natural point to mention new symptoms before the next pen is dispensed. Ongoing monthly reviews are part of the aftercare, so you are not left to work it out alone.

If your congestion is mild and you feel otherwise well, it is reasonable to carry on while you monitor it, as long as you have raised it with a professional if it persists. If it is severe, or you have any of the warning signs, get medical help straight away and decide about your injection afterwards, on advice.

09 · What to expect from treatment

What to expect from treatment overall

People often ask how much weight they can lose in a set period. In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.²

These are trial averages — individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² Trial averages do not predict your own result.

If you feel something is off, such as congestion or any other new symptom, raise it at your reviews with the prescribing team. Tell the prescriber what you have noticed, and ask whether it makes sense to hold at a dose for longer, or whether it is simply unrelated.

Honest expectations matter more than reassurance. Mounjaro is an effective licensed treatment for many people, but it is not right for everyone, and a symptom you find hard to live with is a fair reason to reassess.

10 · 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