Mounjaro is a groundbreaking medication for supporting weight loss. In this guide, we’ll answer some important questions about how Mounjaro works, including how long Mounjaro takes to work it takes to kick in, so you have everything you need to know in order to get started.
What is Mounjaro?
Mounjaro (also known as tirzepatide) is an injectable medication that aids weight loss by regulating blood glucose and balancing energy levels.
How does Mounjaro work?
Tirzepatide (Mounjaro) works by stimulating receptors for two hormones: glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). GLP-1 helps to regulate blood glucose levels, suppressing your appetite and slowing down the emptying of the stomach to keep hunger at bay. GIP enhances the effects of GLP-1 by regulating the energy balance in your brain and fat cells.
Does Mounjaro work for weight loss?
Mounjaro (tirzepatide) works slightly differently from other weight-loss injections like Wegovy.
While Wegovy works by activating a single hormone pathway called GLP-1, Mounjaro activates two hormone pathways — GLP-1 and GIP. These hormones help regulate appetite, feelings of fullness and how the body uses energy.
In clinical trials, people with obesity who used higher doses of Mounjaro, alongside diet and lifestyle changes, achieved significant weight loss over time. Some losing over 20% of their body weight after around 72 weeks of treatment. Studies suggest that, on average, weight loss with Mounjaro may be greater than with medicines that work on GLP-1 alone, although results vary from person to person.
How long does Mounjaro take to work?
Mounjaro starts to work immediately after your first injection and can start to reduce your appetite and food cravings within 7 days. Research has found that by week 24, patients taking the higher doses of Mounjaro (10 mg and 15 mg) can lose, on average, close to 15% of their starting body weight. Weight loss then continues to increase over time, the longer you take the medication.
How do I choose the right Mounjaro dose?
Mounjaro KwikPens come in doses of 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.
For people new to Mounjaro, treatment often starts at a lower dose to help the body adjust. If you’ve previously used another weight-loss medication, like Wegovy, your starting dose may be different.
When switching treatments, a clinician will decide the most appropriate dose based on your individual circumstances and a clinical assessment.
How do you get Mounjaro?
You can order Mounjaro with a prescription after being assessed as suitable by one of our regulated and qualified prescribing pharmacists.
Can I get Mounjaro on the NHS?
Mounjaro is only available on the NHS if you have type 2 diabetes. It’s not yet been approved for weight loss treatment on the NHS, although this is currently under review and it may become available as an NHS prescription for those who meet certain criteria.
Mounjaro dose schedule
Mounjaro is injected into the skin (subcutaneously) by the user. Each Mounjaro KwikPen contains 4 full doses. Each dose should be taken on the same day every week – at any time of day. We recommend planning a 15-minute window at a convenient time in your weekly routine and setting an alarm to remind yourself to take your dose.
If you want to change the day of your dose – for example, switching from Monday to Wednesday – make sure you leave at least 72 hours (3 days) between doses.
Take a look at our how-to video for step-by-step instructions on administering your first dose.
What should I do if I miss a dose?
If you forget to take your scheduled dose of Mounjaro, take it as soon as possible within 4 days of the missed dose. If more than 4 days have passed, skip the missed dose and take the next dose on your regularly scheduled day. Don’t take two doses of Mounjaro within three days of each other.
Where to inject Mounjaro
Mounjaro is injected into the skin of the front of the upper thigh, upper arm or abdomen. It’s been reported that discomfort is more commonly experienced when injecting into the thigh, so if you’re worried about the pain when injecting, start with your abdomen. If you don’t want to administer the dose yourself, someone else can inject into the back of your upper arm.
You can inject each dose into the same general area of the body, but you must change the injection site each time a dose is administered. Remember to always read the Patient Information Leaflet that comes with your medication.
Mounjaro disposal
Once all four doses have been used, dispose of your Mounjaro KwikPen in a sharps disposal container or take them to your local pharmacy. Do not dispose of your used pens in your household waste.
FAQs
Does Mounjaro need to be refrigerated?
Yes, but only before use. Once the first dose of your KwikPen has been administered, store the pen at room temperature, out of direct sunlight and away from heat sources, in its original packaging for a maximum of 30 days. If Mounjaro is stored above 30ºC or under 2ºC, it can become unsafe to use and must be discarded.
What class of drug is Mounjaro?
Mounjaro is a type of drug called a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. Mounjaro is the first medication in the GIP/GLP-1 receptor agonist drug class.
Is Mounjaro a hormone?
Mounjaro mimics both the GLP-1 and GIP hormones, but it’s not a hormone itself.
Is Tirzerpatide the same as Mounjaro?
Yes. Mounjaro is the brand name for the drug tirzerpatide.
Does Mounjaro build up in your body?
Weight loss medications do build up in your system, which is why you need to leave at least three days between doses and a minimum of four weeks when switching between medications (e.g. from Wegovy to Mounjaro).
Can you drink alcohol on Mounjaro?
Although alcohol doesn’t directly interact with the drug itself, it’s not recommended to drink alcohol while taking Mounjaro. This is because alcohol has the potential to heighten the risk of experiencing side effects and impacts factors like blood glucose levels.
Will I experience side effects?
If you’d like to know more about potential side effects, take a look at our side effects guide for up-to-date information.
References
https://www.medicines.org.uk/emc/files/pil.15481.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822791/
https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
