GLP-1 App Tracker: What to Track and Which App Fits (October 2026)

01 · The core answer

Which GLP-1 tracker app should you use?

Choose the app you will open every week. Look for dose and date logging, a reminder for injection day, a place to note side effects, and a weight chart. Everything else is a bonus.

If you are a customer, GLPTrackr is our free companion app for tracking a GLP-1 journey, and it runs on both iOS and Android. If you are comparing options, our guides to GLP-1 tracker apps and the Mounjaro tracker app go into more detail on features.

02 · What to do next

Do you need an app at all?

No, an app is a convenience rather than part of the treatment. If you prefer paper, a printable weight loss tracker does the same job.

If you are not yet on treatment, the Mounjaro pen page explains how a free online consultation works, with a prescriber review before anything is supplied.

03 · What to track

What to track on a GLP-1 medicine

Track the basics consistently. Mounjaro is a once-weekly injection, so the most useful entries are the date, the dose strength and the injection site.¹ Dose strengths run from 2.5mg up to 15mg, and the dose moves up after at least 4 weeks on each dose, depending on how you respond, so a record shows when you last changed.

Add side effects as short notes. Nausea, reflux or constipation noted with the day and what you ate gives your prescriber something concrete at a review. Weight is worth logging at the same time each week, not daily, because day-to-day swings are mostly fluid.

Your in-use pen can stay out of the fridge at a temperature not above 30°C for up to 30 days after first use, so a note of the date you started each pen is also handy. Keep pens in the fridge at 2–8°C and never freeze them.¹³

04 · Food tracking

Should you track food on a GLP-1?

Tracking food is optional, but it can help you see whether you are getting enough protein while appetite is low. Treatment is licensed alongside a reduced-calorie diet, so the aim is a sustainable deficit, not a perfect food list.¹¹

No food is banned. Prioritise protein at each meal, vegetables and fibre, and regular fluids. Many people feel worse after very fatty, fried or very sugary food, and large portions sit heavily because the stomach empties more slowly, so smaller, slower meals work better.¹³

If logging makes you anxious or obsessive, stop. A simple habit, such as a protein source at every meal, gives most of the benefit without counting anything.

05 · Protein and fluids

Protein, muscle and fluids: the useful things to log

Protein and fluids are the two things most worth checking in a tracker. Some of any rapid weight loss comes from lean tissue, and protecting muscle protects your metabolism, strength and appearance. The two levers are adequate protein at every meal and resistance exercise on two or more days a week.¹¹

Drinking enough matters more than usual because reduced appetite means less fluid from food. Vomiting or diarrhoea can dehydrate you quickly. If you cannot keep fluids down, contact your clinical team — dehydration needs medical help straight away.¹³

06 · Free options

Free GLP-1 trackers and Android

Free is the norm for this kind of app, and GLPTrackr is free on both iOS and Android. Always check what data an app collects before you enter health details, and read its privacy policy.

For more on the choices, see our guides to a free GLP-1 tracker, a free GLP-1 app and Mounjaro tracker app downloads. If an app promises dramatic weight-loss results or sells supplements as a substitute for treatment, treat it with caution. Supplements sold as natural GLP-1 boosters are not equivalents and are not substitutes for prescribed treatment.¹³

07 · Limits of apps

What an app cannot do

An app records your results but cannot predict them. In the SURMOUNT-1 trial, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone. These are trial averages: individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² Your own chart may look different from any average, and that is normal.

An app also cannot judge whether a symptom is serious. Tell your prescriber about any new or lasting symptom, and you can report suspected side effects through the Yellow Card scheme.¹⁹ If you stop treatment, the medicine takes roughly four to five weeks to clear, and nothing needs doing while it does.¹

08 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹