Mounjaro FAQs

Mounjaro is the brand name for tirzepatide, a prescription-only injectable medication that is licensed in the UK for the treatment of adults with type 2 diabetes. It may also be prescribed off-licence as part of a structured weight management plan for eligible patients. Mounjaro is a once-weekly injectable that mimics the action of hormones involved in blood sugar and appetite regulation.

This treatment is only available on prescription following a consultation with a qualified healthcare professional. It is not suitable for everyone, and eligibility will depend on individual health circumstances.

Tirzepatide is the active ingredient in Mounjaro and was developed by Eli Lilly. Clinical trials have shown it can lead to substantial weight loss.

Although originally developed to treat type 2 diabetes, Tirzepatide is now licensed by the MHRA for weight management in the UK. If you are familiar with Ozempic or

Wegovy, it works in a similar way—by helping you feel fuller for longer, reducing cravings, and lowering your calorie intake.

Its effectiveness is due to its dual mechanism: acting on both GLP-1 and GIP receptors to increase insulin, reduce glucagon, slow digestion, and suppress appetite. In phase 3 clinical trials (e.g., SURPASS), weight loss ranged between 11% and 17% over 52 weeks—greater than seen with other treatments.

However, individual results may vary.

Switching between licensed medications such as semaglutide (Wegovy) and tirzepatide (Mounjaro) must be clinically justified. Your prescriber will assess factors such as your current progress, previous dose, medical history, and treatment goals. Any decision to switch must be based on a comprehensive review of your individual case and the current clinical evidence.

We do not recommend making any changes to your medication without medical advice.

Wegovy contains semaglutide, which mimics one hormone (GLP-1), while Mounjaro (tirzepatide) mimics two hormones—GLP-1 and GIP. These hormones affect appetite, satiety, and insulin secretion. However, both medications are prescription-only and are not interchangeable without clinical review.

Your prescriber will help you understand the differences and determine which option may be more appropriate for your needs, based on your health history, response to previous treatments, and treatment goals.

There is currently no confirmed waiting period between stopping Wegovy and starting Mounjaro. Wegovy has a long half-life, so it may take a few weeks to clear from your system, depending on your dosage. Once this timeframe is established, we will inform you during your consultation.

You may notice some symptoms after stopping Wegovy—such as increased appetite, weight gain, mood changes, or digestive issues. To help prevent this, it may be advisable to taper your dose gradually before stopping. Continue to follow a healthy lifestyle with a reduced-calorie diet and regular activity during this time.

Tirzepatide (Mounjaro) activates receptors for two hormones (GLP-1 and GIP) involved in appetite control and glucose metabolism. These hormones help regulate blood sugar, slow digestion, and increase feelings of fullness. In clinical trials, this dual action has been shown to support blood sugar control in patients with type 2 diabetes and, in some cases, to reduce body weight when used alongside lifestyle changes.

Tirzepatide is administered as a once-weekly subcutaneous injection and should only be used under clinical supervision.

As with all prescription medications, side effects are possible. Common side effects reported with tirzepatide include:

• Nausea
• Diarrhoea or constipation
• Vomiting
• Reduced appetite
• Fatigue

More serious but less common side effects may include pancreatitis, gallbladder issues, or allergic reactions. Your prescriber will discuss the full list of known side effects with you before starting treatment, and will advise you on what to do if you experience any symptoms.

Tirzepatide is licensed in the UK for treating type 2 diabetes. It may also be prescribed off-licence as part of a weight management programme in certain cases. Your eligibility depends on factors such as:

• BMI
• Past treatment history
• Medical conditions and medications
• Risk factors or contraindications

A full consultation is required before prescribing. Treatment must be part of a structured programme that includes lifestyle advice, behavioural support, and regular clinical reviews.

In studies, average weight loss on Mounjaro was around 10% after 6 months, compared to 6% with Ozempic. After 12 months, participants lost up to 15% of their body weight, compared to 8% on Ozempic.

One-year data shows that 42.3% of people taking Mounjaro lost at least 15% of their body weight, compared with 19.3% on Semaglutide.

UK Slimming Club makes it simple to begin a medical weight loss programme that works. With our online consultation form, you can get started quickly and safely. Our experienced medical team will assess your suitability and provide tailored support to help you achieve your weight loss goals and maintain long-term success.

Weight loss varies by individual, but many people notice a difference within the first few weeks. Sustainable weight loss takes time, and consistency with your treatment plan and lifestyle changes is key.

There are six different doses available, ranging from the starting dose of 2.5mg to the maximum dose of 15mg.

You must always start at the lowest dose of 2.5mg which you will inject once a week for a month (4 weeks) this will allow your body to adjust to the medication and help reduce the risk of potential side effects.

After this dose, if necessary, you might move on to the next dose which is 5mg, and gradually increase your dose by 2.5mg every 4 weeks. The maximum dose is 15mg. It is important to remember NOT to titrate to the next dose if the current dose you are taking is managing your hunger and cravings. Gradually increasing your dose (titration) helps your body adjust to the medication and reduces the risk of potential side effects.

What dose of Mounjaro will I need? (Dose Escalation Chart)

This depends on how recently you stopped taking tirzepatide and your response to previous treatment. Mounjaro is typically started at a lower dose and gradually increased to reduce the risk of side effects. If you are restarting treatment, your prescriber will assess whether it is appropriate to begin at a higher dose, based on your previous tolerance and current clinical needs. Prescribing evidence will need to be provided.

Self-adjusting your dose is not recommended and can be unsafe. Always follow your prescriber’s advice.

• Mounjaro is considered safe for long-term use.
• The benefits of sustained treatment often outweigh the risks, particularly when overseen by a qualified healthcare professional.
• Clinical trials also revealed a reduced risk of adverse cardiovascular events, including heart attacks or strokes.
• The Virtual Slimming Clinic will conduct a thorough assessment to ensure that long-term use is appropriate for your specific medical condition.
• It is crucial to remain vigilant for any side effects and report them to us.
• This allows for timely adjustments to your treatment plan, ensuring that you continue to benefit from the medication.

If treatment with tirzepatide is stopped, the appetite-suppressing and blood sugar-regulating effects will gradually wear off. This may lead to a return of previous symptoms such as increased appetite, weight gain, or elevated blood sugar, depending on the reason it was prescribed.

Long-term success with any weight management programme also relies on maintaining lifestyle changes. If you’re considering stopping treatment, speak to your prescriber first to discuss a maintenance plan and any available alternatives.

Mounjaro should NOT be taken with other weight-loss drugs, such as Saxenda or Wegovy. This will increase the risk of unwanted side effects.

KEEP OUT OF REACH OF CHILDREN OR VUNERABLE ADULTS

Storing your Mounjaro correctly will ensure it remains effective and safe so that you can get the most from your medication.

How should I store my Mounjaro pen? Follow these guidelines to store Mounjaro properly:

• Keep Mounjaro in its original packaging, in order to protect it from light, moisture, and other external factors.
• Store Mounjaro in the refrigerator between 36°F (2°C) and 46°F (8°C) – However, Mounjaro can be stored at room temperature (but below 30 degrees) for 6 weeks whilst in use, without having any effect on the efficacy of the drug (see side of box to clarify).
• Avoid freezing Mounjaro, as extreme temperatures can render it ineffective.
• Protect from light, as Tirzepatide is sensitive to light exposure, so it’s essential to keep Mounjaro in its packaging and store it away from direct sunlight or brightly lit areas.
• Do not leave the needle attached after each injection, as this could be dangerous and poses a risk of infection.

Each Mounjaro pen will last until its expiration date, but once used for the first time, it will last 6 weeks. Always check the medication through the glass window on the pen before use, to make sure it’s not cloudy or coloured.

How long does a Mounjaro pen last?

Each Mounjaro pen contains enough medication for four doses, and as Mounjaro is injected once weekly, one pen will last 4 weeks

What should I do if I have missed a dose of Mounjaro?

It is important that you take your Mounjaro each week, in order to maintain a consistent level of medication in your system.

• If you miss a dose of Mounjaro, inject the next dose as soon possbile as long as it is within 4 days (96) hours after the missed dose.
• If you miss a dose of Mounjaro and the next scheduled dose is less than 2 days away (48 hours), do not administer the dose. Take your next dose on the regularly scheduled day.
• If you miss doses of Mounjaro for more than 2 weeks, take your next dose on the regularly scheduled day or call your health care provider to talk about how to restart your treatment.

Important: Do not double up on your dose to make up for the missed dose!

It is advisable to stop or limit alcohol consumption while using Mounjaro.

Alcoholic beverages can be high in calories and counterproductive to weight-loss efforts.

Eating a Balanced Diet with Mounjaro

Making sure you are getting all the nutrients your body needs for optimal functioning while taking Mounjaro can be achieved by eating a balanced diet. It may also reduce the risk of undesirable side effects while supporting the drug’s effects on blood sugar regulation and weight loss.

What should I eat while taking Mounjaro? A balanced diet typically includes eating a variety of foods from all the major food groups. These include:

• Fruits and vegetables.
• Whole grains.
• Lean proteins.
• Healthy fats or dairy.

Mounjaro can be taken at any time of day, with or without food. The choice is entirely yours.

The important thing to remember is that you inject Mounjaro on the same day each week.

You will inject Mounjaro once a week.

If you want to change the day of the week you take your dose, make sure there are at least 3 days (72 hours) between doses.

Mounjaro (Tirzepatide) is a once-weekly injection.

You will start your weight loss journey on the lowest dose; follow the dosing schedule until you reach a dose that is suited to you. You will not need to move up to the highest dose if your appetite is reduced by a lower dose.

You should always make sure that you pick a date and time that works best for. Make sure that you take your dose of Mounjaro on the same day each week as this allows the medication levels to remain steady in your body and work effectively.