Mounjaro Starting Dose: What to Expect When You Begin

Both Mounjaro and Wegovy follow a step-up titration approach, beginning at a lower dose and increasing over time under prescriber guidance. Understanding the starting strengths can help you feel oriented when you first begin — but how long you stay at each stage and when (or whether) your dose changes is entirely your prescriber's call, based on how you are responding.

Mounjaro starting dose

The starting dose of Mounjaro is 2.5 mg once weekly. This is a pre-filled pen and is injected subcutaneously (under the skin) once a week. The 2.5 mg dose is considered an introductory strength — its purpose is to help your body adapt to the medicine before any potential dose adjustment is considered. Commonly referenced strengths for Mounjaro include 2.5, 5, 7.5, 10, 12.5, and 15 mg, though not everyone progresses through every stage.

Wegovy starting dose

The starting dose of Wegovy (semaglutide) is 0.25 mg once weekly. Like Mounjaro, Wegovy uses a gradual titration schedule: the 0.25 mg strength is an introductory dose intended to support tolerability at the outset. Commonly referenced strengths include 0.25, 0.5, 1, 1.7, and 2.4 mg. Again, how and when any progression occurs is determined by your prescriber. For more detail on the Wegovy titration pathway, see how Wegovy doses are structured or explore semaglutide dosing for weight loss.

Why start low?

Starting at a low dose is standard practice with GLP-1 and dual GIP/GLP-1 receptor agonist medicines. These medicines act on appetite-regulating pathways and slow gastric emptying, effects that can cause gastrointestinal side effects — such as nausea, indigestion, or changes in bowel habits — particularly in the early weeks. A gradual introduction helps many people tolerate the medicine more comfortably, though individual experience varies. If you are just beginning your journey, what to expect on your first dose of Mounjaro covers the early experience in more detail.

According to the electronic Medicines Compendium (eMC), both medicines are prescription-only and must be used under appropriate medical supervision. Always refer to the patient information leaflet supplied with your medicine for the full prescribing details relevant to you.

Keeping accurate records of your doses from day one can be genuinely useful — particularly when you have a follow-up appointment with your prescriber and want to show a clear picture of your journey so far.

GLP Trackr's dose logging feature lets you record each injection as you go: the dose strength, the date, and the time. That means if you are ever unsure whether you took your weekly injection, or want to confirm exactly when your last dose was, the information is right there. The app also sends dose reminders so your weekly schedule stays on track from the very first pen.

As you move through your treatment, having a documented log of every dose — including which strength you were on at each point — gives you something concrete to bring to your prescriber, rather than trying to recall it from memory. GLP Trackr's doctor report feature can help you summarise that data in a format useful for appointments. For a broader look at how Mounjaro doses are typically structured over time, the Mounjaro dosing guide covers the full picture.

Any decision about your dose — including when to begin, whether to stay at the starting strength, or when to adjust — should always be made with your prescriber. GLP Trackr helps you record your journey; it is not a substitute for their guidance. If you experience symptoms that concern you, contact your healthcare professional promptly.

Start logging your doses from your very first injection — GLP Trackr is free to try for 7 days on the App Store and Google Play.