Mounjaro Stock Issues: What to Know If Your Pen Is Unavailable

Mounjaro (tirzepatide) is a prescription-only, once-weekly injectable medicine that acts on both GLP-1 and GIP receptors. Since its availability for weight management expanded, demand has at times outpaced supply, leading to periodic shortages at pharmacies in several countries.

Why shortages happen

Stock issues can arise for a number of reasons: manufacturing capacity constraints, rapid growth in the number of people being prescribed the medicine, logistics and distribution factors, and the time required to scale production of a relatively new treatment. These factors are generally outside any individual's control.

Which dose strengths are typically affected

Shortages do not always affect every dose strength equally. Certain strengths — often those most commonly used during titration — can run low while others remain available. Your prescriber or pharmacist is best placed to tell you what is currently accessible and what that means for your treatment plan. Never adjust your dose yourself in response to a shortage — that is a decision that belongs with your prescriber.

What to do if your pen is out of stock

• Contact your prescriber or doctor promptly and explain the situation — they may be aware of the shortage and have guidance ready.
• Try more than one registered pharmacy, as stock levels can vary by location.
• Do not source the medicine from unregistered or unverified suppliers. Prescription medicines should only be obtained through legitimate, regulated channels.
• Keep a record of when the shortage started, which strengths were unavailable, and any doses you missed — this information is useful when you speak to your prescriber.

For context on how shortages are monitored in the UK, the MHRA publishes information on medicine supply through official MHRA guidance. If you are outside the UK, check your national medicines regulator for equivalent updates.

For broader information about Mounjaro and how to manage your prescription, see our Mounjaro guide. You may also find it useful to read about Mounjaro stock availability and the latest Mounjaro stock updates.

A supply gap is stressful, but keeping a clear record of your journey during that period can make a real difference when your treatment resumes.

How GLP Trackr helps during a shortage

The most immediately useful feature when Mounjaro is unavailable is dose logging. GLP Trackr lets you record every injection — date, dose strength, and site — so you have a precise history of exactly when your last dose was taken and how long any gap has lasted. That record becomes genuinely valuable at your next prescriber appointment, where decisions about resuming or adjusting your schedule will be made.

Beyond dose logging, the app's side-effect and wellbeing tracking lets you log how you feel day to day during a break from the medicine — noting any changes in appetite, energy, or mood. This gives both you and your prescriber a clearer picture of your experience rather than a vague recollection.

If you have been managing your weight and nutrition while on Mounjaro, the food and weight logging features mean you can continue tracking those habits regardless of whether a dose has been taken, keeping consistency in the parts of your journey you can control.

For more on navigating common challenges with your prescription, take a look at our page on common Mounjaro concerns.

A note on safety: any decision about what to do when a dose is missed or delayed — including whether to take a late injection or wait until the next scheduled date — should be made with your prescriber or doctor, not independently. GLP Trackr helps you record what has happened so that conversation is informed and productive; it is not a substitute for professional guidance.

Keep your journey documented even when supply is patchy. Download GLP Trackr on the App Store or Google Play and start a free 7-day trial — your dose history, wellbeing notes, and weight data will all be there when your next pen arrives.