Mounjaro 2.5mg Pen — Starting Dose

Yes. Mounjaro 2.5mg is in stock at Voy with free next-day delivery. Once you complete your online assessment and a UK-registered prescriber approves your treatment, your pen is dispatched in discreet packaging.

If you're not losing weight on 2.5mg, you're not alone. The 2.5mg starting dose is designed to help your body adjust to tirzepatide, not to drive significant weight loss. Most weight loss happens once you move up to higher doses, where the dual GLP-1 and GIP action becomes more pronounced.

In clinical studies, people lost around 4% of their starting weight by week 4 on 2.5mg. Some people see less, some see more, and some see no change at all in the first month. This is normal.

After 4 weeks, you'll usually move up to 5mg, where weight loss typically picks up.

Tirzepatide (the active ingredient in Mounjaro) has an elimination half-life of around 5 days, meaning it takes about 5 days for half the drug to leave your body. After about 3 weeks, more than 90% of the medicine is cleared, with only small traces remaining by 4 weeks. Tirzepatide is usually considered fully cleared within 4 to 5 weeks of the last dose.

Most people stay on Mounjaro 2.5mg for 4 weeks. If you tolerate it well, your dose will then increase to 5mg. Some people stay on 2.5mg longer, for example if side effects need more time to settle, or if appetite control and steady weight loss are already good at this dose.

After 5mg, the dose continues moving up gradually following the standard titration schedule. Skipping doses or jumping to a higher strength too quickly can increase the risk of side effects. The aim is to find your stable dose: the one with minimal side effects and the best results.

Mounjaro 2.5mg is the starting dose, taken for 4 weeks to help your body adjust to tirzepatide. 5mg is the next dose up in the titration schedule, where most people start to see noticeable weight loss.

In clinical trials, people lost around 4% of their starting weight by week 4 on 2.5mg. By week 8, after moving up to 5mg, they lost around 6%. As the dose increases, the dual GLP-1 and GIP action becomes more pronounced and weight loss typically accelerates.

Both doses are taken once weekly. Side effects can return or new ones appear at the higher dose, but they usually settle within 1 to 2 weeks.

If you've missed one dose and it's been less than 4 days, take it as soon as possible, then continue with your usual weekly schedule.

If more than 4 days have passed, skip the missed dose and take your next dose on your usual day. Don't take two doses close together to make up for a missed one, as this can increase the risk of side effects.

If you've missed more than one dose, call our clinical hotline on 020 3912 9885 or message your clinical team in the Voy app. Your dose may need to be adjusted before you restart, depending on how long it's been since your last injection.

Yes. Store unopened Mounjaro pens in the fridge between 2°C and 8°C. Don't freeze them.

Once you've used a pen for the first time, you can keep it at room temperature (up to 30°C) for up to 30 days, or back in the fridge if you prefer. After 30 days, the pen must be discarded, even if there are doses left.

Each Mounjaro pen contains 4 weekly doses, so if you use it as planned each week, you'll finish it within the 30-day window.

Each Mounjaro 2.5mg KwikPen contains four doses, one for each weekly injection. Inject Mounjaro once a week into your stomach, thigh, or upper arm. You can take it any time of day, with or without food. Rotate your injection site each week to reduce skin irritation.

See our step-by-step injection guide for the full process.

The Mounjaro KwikPen clicks as you turn the dial, but you don't need to count them. A full 2.5mg dose is 60 clicks. After priming the pen, turn the dial until '1' shows in the dose window. That's your full 2.5mg dose loaded and ready.

The Mounjaro 2.5mg pen contains four doses, one for each weekly injection, so it lasts four weeks.

If you're ever unsure your pen is dosing correctly, call our clinical team on 020 3912 9885 or message us in the Voy app. See our step-by-step injection guide for the full process.

Yes. Mounjaro and Zepbound contain the same active ingredient (tirzepatide) and are made by the same company (Eli Lilly). They work in the same way and come in the same dose strengths.

The difference is regional branding and licensing. In the US, Mounjaro is licensed for type 2 diabetes only, and Zepbound is the brand used for weight management. In the UK, Mounjaro covers both, so you'll only ever see Mounjaro here, even when using it for weight loss.

Mounjaro is licensed for adults with a BMI of 30 or above (obesity), or a BMI of 27 to 30 (overweight) with at least one weight-related health condition such as high blood pressure, high cholesterol, sleep apnoea, type 2 diabetes, or pre-diabetes.

At Voy, our clinical team may also prescribe Mounjaro from BMI 25 where the benefits outweigh the risks. This is an off-label use, reviewed on a case-by-case basis by a UK-registered prescriber.

Mounjaro isn't suitable for everyone. It's not prescribed during pregnancy, breastfeeding, or to people with certain medical conditions, including a history of pancreatitis, thyroid cancer, severe digestive conditions, or active cancer treatment, among others.

Your eligibility is checked through our online assessment, which asks about your full medical history, current medications, and any conditions that could affect treatment. Be open during your assessment so your clinician can give you the safest treatment.

Most side effects on Mounjaro are mild and settle on their own. There are two reactions worth knowing about, just so you know what to look out for.

Pancreatitis (inflammation of the pancreas). This affects up to 1 in 100 people. The main sign is severe, lasting pain in your stomach area that may spread to your back, with or without nausea or vomiting. If you notice this, stop taking Mounjaro and contact a doctor straight away. Read more on Mounjaro and pancreatitis.

Severe allergic reaction. This affects up to 1 in 1,000 people. Signs include breathing problems, swelling of your lips, tongue, or throat, difficulty swallowing, or a fast heartbeat. If this happens, get medical help right away.

If you're not sure whether something you're feeling is normal, message your clinical team in the Voy app or call our hotline on 020 3912 9885.

Hair loss has been reported by people taking Mounjaro, affecting around 5% of patients in clinical trials compared to 1% on placebo. But Mounjaro isn't believed to cause hair loss directly. It's more likely a knock-on effect of rapid weight loss, which can temporarily push more hairs into the shedding phase of the growth cycle.

This type of hair loss is usually temporary. Most people see hair regrow on its own once weight loss stabilises. Eating a balanced diet with enough protein, iron, and B vitamins can help support hair health during treatment.

Yes. Mounjaro 2.5mg is one of the possible starting points when switching from Wegovy, depending on which Wegovy dose you were on, how long it's been since your last Wegovy injection, and how well you've tolerated it.

Wegovy and Mounjaro contain different active ingredients (semaglutide and tirzepatide), so switching is done under clinical guidance. If you're already a Voy customer, you can start the switch in the Voy app by answering a short switching questionnaire. If you're switching from another provider, complete our online assessment so we can review your treatment history and recommend the right Mounjaro starting dose for you.

No. Mounjaro is a once-weekly injection. Take one 2.5mg dose per week and follow the standard titration schedule. Doubling up doesn't speed up weight loss, and it can significantly increase the risk of side effects like nausea, vomiting, and stomach discomfort.

If you're unsure about your dose or schedule, call our clinical hotline on 020 3912 9885 or message your clinical team in the Voy app.