• Confidential assessment
  • Reviewed by our doctors
  • Same-day collection

Product features

  • Genuine EU-licensed medication

  • Can help you lose weight alongside a healthy, balanced diet

  • Use once a week

What is Mounjaro (Tirzepatide)?

Mounjaro contains tirzepatide, the first medicine to activate both the GIP and GLP-1 receptors. It was authorised in the EU in 2022, got approved in the UK in November 23, and can now be prescribed for weight loss in Ireland.

See your other weight loss options.

Who is eligible for Mounjaro?

You may be suitable if you:

  • have a BMI of 30 or above
  • have a BMI of 27 or above and at least one weight-related problem (this could be high blood pressure, heart disease or sleep apnoea).

You should not use it if you:

  • are allergic to any ingredients,
  • have severe digestive problems or a history of pancreatitis, have untreated diabetic eye disease,
  • take certain diabetes medicines (speak to your doctor about any you’re taking)
  • are pregnant, breastfeeding or under 18 years.

How does Mounjaro work for weight loss?

Mounjaro is a tirzepatide injection that turns on the GIP and GLP-1 switches in your gut, so you feel fuller sooner, stay satisfied longer, and burn blood sugar more efficiently. It helps to:

  • Reduce your appetite so you may want to eat less,
  • Slow your stomach emptying so you stay feeling fuller for longer
  • Trigger insulin release only when needed, helping you control sugar spikes that happen after a meal.

What receptors does Mounjaro affect?

Most weight-loss pens act on GLP-1 alone. Mounjaro is a dual GIP + GLP-1 agonist, and trials show this dual action can lead to greater average weight loss than GLP-1-only medicines.

How effective is Mounjaro for weight loss?

How to use Mounjaro injections for weight loss

Pick your ‘Mounjaro day’, take the pen out of the fridge 30 minutes beforehand, and inject your stomach area, thigh or upper arm.

Key points

  • You can use your mounjaro pen any time of day.
  • Vary the exact area you inject on different days to avoid skin irritation.
  • Store unused pens at 2–8 °C.
  • Once started, a pen can be used for 21 days if kept below 30 °C.
  • Put used Mounjaro pens in a sharps bin and return them to your pharmacy.

Mounjaro dosage and schedule

Week Dose Purpose

1-4

2.5mg

Starter dose to limit side effects

5-8

5mg

Standard maintenance

9-12

7.5mg

Next titration

13-16

10mg

Next step if your doctor thinks your body is responding well

17-20

12.5mg

Next titration

21+

15mg

Maximum dose

Your doctor may keep you at a lower step for longer if Mounjaro is causing you any side effects.

What to do if you miss a dose

  • Less than 4 days late? Inject as soon as you remember, then return to your usual schedule.
  • More than 4 days late? Skip the missed dose and inject on your next scheduled day.
  • Never inject two doses within three days.

Do you have to take Mounjaro forever?

Lost weight can return if you stop Mounjaro medication suddenly. Once they’ve met their goals, many people move to a maintenance dose or continue with lifestyle changes alone.

We’ll review your progress every 3–6 months and plan the next steps together.

Mounjaro side effects

As with all medications, there is a chance you may experience some side effects when taking Mounjaro®. These side effects often get better over time as your body gets used to treatment or you may only get them while your dose is being increased.

Common

(affecting up to 1 in 10 people, usually settling after a few weeks)

Uncommon or rare

(affecting up to 1 in 100 - or 1 in 1000 if rare - people, contact a doctor if severe)

Nausea, diarrhoea, constipation, indigestion, tummy pain, reduced appetite, vomiting, injection-site reactions, dizziness, hair loss

Gallstones, pancreatitis (severe abdominal or back pain), injection-site pain, serious allergy, changed sense of taste, change in skin sensation

Most Mounjaro weight loss side effects appear during the first few weeks of treatment or when you step up to a higher dose. Gastro-intestinal symptoms (nausea, diarrhoea, stomach pain, vomiting) are more common and sometimes stronger after each dose increase. This is why your doctor may keep you on each step for at least four weeks, so your body can adjust. In clinical trials, these effects usually eased as people settled on a stable dose.

As for Mounjaro long term side effects, a very rare one is pancreatitis (potentially affecting fewer than 1 in 1,000 people). The risk doesn’t seem to grow over time, but you should seek urgent help if you get sudden, severe stomach or back pain.

Read the MHRA Mounjaro Patient Information Leaflet and the EMA Summary of Product Characteristics for Tirzepatide for full side effects and warnings.

Managing side effects

If you’re experiencing side effects from Mounjaro or other GLP-1 medications, it can help to:

Answers to frequently asked questions

  • Is Mounjaro available in Ireland?

    Yes. You can get Mounjaro on prescription but not currently from the HSE.

  • Can you get Mounjaro over the counter?

    No. You can only get Moumjaro in pharmacy or online with a prescription. If you’re going to buy mounjaro online, remember to use a regulated service like ours.

  • What diet should I follow on Mounjaro?

    For Mounjaro to be effective you should eat a low calorie, low fat healthy diet combined with regular exercise. You should limit the calories you eat which come from fat to under 30% of your diet and spread your daily intake of fat, carbohydrate and protein across three main meals.

  • How do I store and dispose of a Mounjaro pen?

    Once in use, store a pen in the fridge (2 °C – 8 °C). Do not freeze a pen and do not use a pen if it has been frozen. Your pen can be stored outside of a fridge after you have used it for the first time but it cannot be warmer than 30 ºC. It can be stored for up to 30 days this way then must be discarded. Drop used pens in a sharps bin and return to your pharmacy or council collection point.

  • Can I drink alcohol on Mounjaro?

    Moderate alcohol doesn’t interact directly with Mounjaro, but it adds calories and can lower your blood sugar. Try to stay within safe drinking limits.

  • Does Mounjaro interact with other medicines?

    Certain drugs can interact with Mounjaro and cause a reaction, so please give our doctors a full list of our medicines you’re taking so they can prescribe safely. Also let them know if you start taking another medication alongside Mounjaro.

    Mounjaro (tirzepatide) slows stomach emptying, so some oral drugs are absorbed more slowly. This can affect medicines that need more precise blood sugar levels such as insulin, sulfonylureas, warfarin, digoxin or oral contraceptive pills. So your doctor may:

    • Lower insulin or sulfonylurea doses to prevent low blood sugar.
    • Ask you to take certain tablets at least one hour before your weekly injection (or several hours after).
    • Suggest extra blood tests or monitoring to check drug levels.

    If you’re a woman taking oral contraceptives you may be advised to use a barrier method for four weeks after starting Mounjaro or after each dose increase.

  • Alternative treatments?

    Other prescription options for weight loss include Xenical (orlistat). Alli is half the strength of Xenical and available over the counter from pharmacies.

    There are a variety of weight loss treatments available on the market, including supplementary dietary pills and surgical options. However, the HSE advises that a healthy diet and regular exercise are the most effective way to lose weight and improve your health in the long-term.

    Compare your options on our weight-loss page.

  • Our weight loss clinic

    If you're having trouble losing weight and think Mounjaro weight loss medication might be right for you, you can request them through our online service. Here's how it works:

    1. You answer some questions about your health.

    2. A doctor checks your answers and approves the treatment, if it's suitable for you.

    3. We'll send your prescription to a local pharmacy. You can pick up your treatment and pay for it the same day.

  • References

How our service works

Online consultation

Step 1

Select a medication and complete a short questionnaire.

Our doctors approve your treatment

Step 2

A doctor will assess your answers and, if suitable, provide a prescription.

In-pharmacy collection

Step 3

Choose collection from your pharmacy with payment in store, or delivery via Healthwave where available. Healthwave orders must be paid for before dispatch.