What is Mounjaro?

Mounjaro (tirzepatide) is a prescription-only injectable medication developed by Eli Lilly. This medication is used for weight loss and weight maintenance in adults. Mounjaro is a GLP-1 and GIP receptor agonist, offering dual-action appetite suppression and improved metabolic control.

Mounjaro is available in pre-filled pens in the following strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.

How does Mounjaro work for weight loss?

Mounjaro works by mimicking two hormones, GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). These hormones help regulate blood sugar and promote a feeling of fullness. By slowing gastric emptying and reducing appetite, Mounjaro helps patients consume fewer calories, which can lead to sustainable weight loss over time.

How effective is Mounjaro for weight loss?

Clinical trials have demonstrated Mounjaro to be an effective medication for weight loss. In the one study, participants lost up to 22.5% of their body weight over 72 weeks when using tirzepatide at the highest dose, alongside lifestyle changes.

Reference: Jastreboff et al., 2022. Tirzepatide Once Weekly for the Treatment of Obesity. 

Who may Mounjaro be suitable for?

Mounjaro may be suitable for adults who:

• Have a BMI of 30kg/m2 or higher, or
• Have a BMI of 27kg/m2 or higher with weight-related conditions, such as type 2 diabetes, high blood pressure, high cholesterol or sleep apnoea.
• Have not achieved adequate weight loss through diet and exercise alone.

Who may Mounjaro not be suitable for?

While Mounjaro (tirzepatide) is effective for many people seeking weight loss, it is not suitable for everyone. There are specific contraindications, cautions, and potential drug interactions that must be considered before approving treatment.

For further information about who should not use Mounjaro, you can refer to the patient information leaflet.

Mounjaro dosage guide

Mounjaro doses are titrated over a period of time in a dosage regime. The doses will be gradually increased so that your body can adjust to the medication and you can manage potential side effect symptoms.

The standard dosing schedule for Mounjaro is as follows:

• Weeks 1–4: 2.5 mg dose weekly
• Weeks 5–8: 5 mg dose weekly
• Weeks 9+: weekly dose may increase to 7.5 mg, 10 mg, 12.5 mg, or 15 mg weekly based on tolerability and clinical response. Dose adjustments are made under supervision depending on tolerability and weight loss progress.

How do I use Mounjaro?

Mounjaro is administered as a once-weekly subcutaneous injection, typically in the thigh, abdomen, or upper arm. The injection is delivered via a pre-filled pen and should be taken on the same day each week, with or without food.

Switch injection sites weekly and divide the chosen area into four sections which will be your injection sites. Inject at least one finger width away from the last injection. If injecting in the abdomen, inject at least 5cm away from the navel.

Each Mounjaro pen has 4 fixed doses, one injection dose of 0.6ml taken weekly. A new needle should be used every time when injecting and after 4 doses have been injected the pen should be disposed of.

You can view the Mounjaro instruction manual here. You can view more information on how to use Mounjaro, including a demonstration video here.

What happens if I miss a dose of Mounjaro?

If you miss a dose:

• If less than 4 days have passed since the missed dose, take it as soon as you remember.
• If more than 4 days have passed, skip the missed dose and continue with your next scheduled injection.
• Do not take two doses within the same week.

What if I cannot tolerate a higher dose of Mounjaro?

If you experience side effects at a higher dose, you may be recommended to:

• Remain at a lower dose for a longer period of time
• Reduce the dose of medication temporarily
• Discontinue treatment if side effects persist

Can Mounjaro be used long-term?

Yes, Mounjaro can be used long-term if tolerated and effective. Many patients benefit from extended use to maintain weight loss and improve health. Regular reviews are required to assess safety and effectiveness.

To be eligible to continue Mounjaro patients long-term, patients would need to achieve a weight loss of at least 5% of their starting body weight after 6 months of regular treatment.

How will I receive my Mounjaro delivery?

You will receive your Mounjaro pen in a parcel insulated with Woolcool packing to maintain a suitable temperature during delivery.

In addition to the pre-filled pen you will receive:

• A sharps bin with your first order
• Needles (one to use for every time you inject)
• Swabs to clean your skin before injecting
• A patient information and instruction leaflet

What if the ice packs have melted in my delivery parcel?

Mounjaro will be delivered in Woolcool packaging, which keeps medications within a safe temperature range during transit. Your parcel will contain ice packs to maintain the cold-chain. If the ice packs are melted when your item is delivered, please do not be alarmed as this is expected and does not affect the integrity of the product provided it is received within the correct time frame.

How do I store Mounjaro?

• Store in a refrigerator (2°C to 8°C)
• Do not freeze
• Once opened, Mounjaro pens can be kept at room temperature (up to 30°C) for up to 21 days
• Always keep out of reach of children.

How do I dispose of Mounjaro pens?

Used pens should be placed in the provided sharps bin. Once the sharps bin is full, contact your local pharmacy or GP surgery who can dispose of the sharps bin.