What is Mounjaro? Effects, use, side effects and approved indications

Mounjaro acts on two receptors, GIP and GLP-1. It is used for type 2 diabetes when diet and exercise alone have not provided sufficient benefit. Do not replace insulin with it on your own. Japanese prescribing information §§4, 5, 8 and 18

Effects on blood glucose and stomach emptying

Stimulating GIP and GLP-1 receptors promotes insulin secretion in response to blood glucose. In studies of non-Japanese patients with type 2 diabetes, fasting and post-meal glucose declined more than with placebo, and changes were also observed in secretion of glucagon, a hormone that raises blood glucose. Simply describing the medicine as “burning fat” does not explain its action. Prescribing information §§18.1 and 18.2.2–18.2.4

Delayed emptying of stomach contents has also been reported. This effect is greatest after the first dose and diminishes with repeated administration. These are pharmacological effects observed in research; they do not directly predict any individual’s appetite or weight change. Studies of glucose control must also be distinguished from assessments of efficacy and safety for cosmetic or weight-loss purposes. Prescribing information §18.2.6

Weight-loss use is off-label

Japan’s Ministry of Health, Labour and Welfare warns that efficacy and safety have not been established for cosmetic or slimming use of Mounjaro. Even when consulting a doctor, it is important to understand the off-label status and possible harm, as well as hoped-for changes. No individual can be guaranteed a particular loss in kilograms or a timeline. Ministry warning

Check not only weight, but also whether you can eat and drink and whether side effects persist. For the approved treatment of type 2 diabetes, the prescribing information calls for regular blood and urine glucose checks and consideration of a treatment change if the effect is insufficient after 3–4 months. This is not a promise that cosmetic use will cause weight loss after 3–4 months.

If changes are limited or nausea or other symptoms are troublesome, tell your doctor about your use and health rather than increasing the dose yourself. Dose increases depend on side effects and excessive weight loss as well as treatment effects. Prescribing information §§7.3, 7.4, 8.2 and 8.9

Considering diet and exercise

Diet and exercise are fundamental to type 2 diabetes treatment. Conversely, very low food intake, intense exercise and excessive alcohol consumption are associated with a risk of low blood glucose. Do not keep skipping meals simply because your appetite has decreased; discuss difficulty eating during your consultation. Prescribing information §§5 and 9.1.3

Weight after stopping

SURMOUNT-4 enrolled adults with obesity or overweight with a weight-related complication. Following a lead-in period with dose escalation to 10mg or 15mg, participants switched to placebo regained weight. This shows that weight loss is not necessarily maintained once achieved. It does not directly describe outcomes with our clinic’s doses or any individual’s course after stopping. Discuss future weight management with your doctor whether continuing or stopping. Authors’ abstract of the original SURMOUNT-4 publication

For the approved treatment of type 2 diabetes, dosing starts at 2.5mg once weekly and increases to 5mg after 4 weeks. Further increases depend on treatment effects and health. This is not a uniform dosing regimen for cosmetic use. Follow your prescription and do not change the amount or interval on your own.

Before self-injection, receive instructions from your healthcare provider on using and disposing of the device, and confirm the steps. Prescribing information §§6, 7 and 8.14

Injection sites and checks before use

The medicine is injected under the skin of the abdomen, thigh or upper arm. Rotate the injection location even within the same body area. Before use, check for device damage, discoloured solution or floating particles. If anything is abnormal, do not use it without checking with a healthcare professional or pharmacist. Follow the product instructions and the training provided by your healthcare provider for detailed handling. Prescribing information §§8.14 and 14

If you miss an injection

The prescribing information states that if at least 72 hours remain before the next scheduled dose, administer the missed dose when remembered. If fewer than 72 hours remain, skip that dose and administer the next dose on its scheduled day. Changing the weekly day also requires at least 72 hours since the previous injection. If you are unsure whether you injected a dose or are uncertain about timing, check with your healthcare provider before taking another injection. Prescribing information §7.2

There are conditions in which the medicine must not be used, including type 1 diabetes and diabetic ketoacidosis. Tell your doctor about previous drug allergies, pancreatitis, serious gastrointestinal disease, intestinal obstruction, abdominal surgery and diabetic retinopathy. If surgery or anaesthesia is planned, also tell the treating doctor that you are using this medicine.

Diabetes medicines such as insulin affect the risk of low blood glucose. Oral contraceptives and warfarin also need to be reviewed. Report all medicines you use, including non-prescription products. Prescribing information §§2, 9 and 10

Pregnancy and breastfeeding

Do not administer the medicine to people who are pregnant or may be pregnant. If pregnancy is possible, discuss contraception during treatment and for 1 month after the last dose with your doctor. Effects on oral contraceptives also require attention. During breastfeeding, a decision must take account of the benefits of treatment and breastfeeding. Prescribing information §§9.4–9.6 and 10

Mounjaro is a prescription medicine. An online consultation is different from ordinary online shopping completed by placing an order: a doctor reviews your medical history, medicines and treatment purpose before deciding whether to prescribe. Prescribing information: regulatory classification

Our clinic offers online consultations, but booking does not guarantee a prescription. See the Mounjaro online consultation page for booking, questionnaire, consultation and delivery information.

When comparing costs, distinguish the price for one injection from four, the strength, and shipping charges. At your consultation, also check whether self-injection training is available, where to seek advice if your health changes during use, and how to store the medicine after delivery.

1. Confirm that cosmetic or weight-loss use is off-label.
2. Do not change the injection dose, interval or other medicines on your own.
3. Tell your doctor about possible pregnancy, your medical history and current medicines.
4. Stop use and promptly seek medical attention for symptoms described above, such as persistent severe abdominal pain.
5. Follow storage conditions and confirm self-injection and device disposal procedures.