We Tested the GLP-1 Tracker Apps — Here's What Each One Quietly Can't Do

The best GLP-1 tracker app depends on your biggest challenge. Shotsy is the most-downloaded and the best free injection tracker. MeAgain is the most complete all-in-one. Glapp is the best free medication-level visualiser. But most apps only log weight and let you type in body fat — they don't prove whether you're losing fat or muscle, and they treat protein as one macro under a calorie total rather than a floor to hit. The full tested comparison is below.

This article is for information only and is not medical advice — talk to your prescriber.

How we tested (and what "best" means for a GLP-1 tracker)

We used each app the way someone on a weekly injection actually would: logging real doses, recording side effects across a dose cycle, entering meals, and checking what happened to progress tracking over several weeks. We didn't grade on screenshots from a marketing page. We graded on whether the app helped with the five things that genuinely matter once you're on a GLP-1:

1. Dose and titration — logging the shot, remembering the next one, and handling the step-up ladder.
2. Injection-site rotation — knowing where the last few shots went so you don't overuse a spot.
3. Side effects — recording symptoms and tying them to the dose, not a flat list floating in a vacuum.
4. Protein and nutrition — because appetite crashes and protein is the macro at risk.
5. Non-scale progress — whether the weight coming off is fat or muscle.

One ground rule shaped every score: a tracker is a companion, not a treatment. None of these apps change what a medication does. They help you stay consistent, spot patterns, and bring better notes to your clinician. Any decision about your dose, your side effects, or your diet belongs with your prescriber or a registered dietitian — the apps that scored well are the ones that make it easy to take that conversation to them.

The comparison table: what each app can and can't track

Here's the matrix. Bold cells are the honest gaps — the thing the app doesn't do.

*Feature sets and free-tier limits change fast in this category — Shotsy shipped body-composition input fields and oral-pill tracking within a single cycle. *

Shotsy

Shotsy is the most-downloaded GLP-1 companion for a reason: it's polished, the free tier is generous, and the injection-logging flow is fast. Version 3.0 added oral-pill tracking and a "Maintenance Mode," and in 2026 it added body-fat and lean-mass fields. Those fields matter — but they're empty boxes you fill from an external scale or DEXA. Shotsy can associate a side effect with a dose, which puts it ahead of the plain symptom lists.

What it can't do: measure body composition for you, enforce a protein floor, or run a 3D scan. If you want those, you're looking for a Shotsy alternative for body composition.

MeAgain

MeAgain positions itself as the all-in-one, and it's close. You get an estimated medication-level graph, progress photos, a friendly AI companion, and broad logging. For a lot of people this is the most complete single app.

What it can't do: derive body-fat from a scan — the body-comp numbers are manual inputs — and it logs protein as one macro under a calorie total rather than a floor you're told to hit.

Glapp

Glapp is the best free way to see your medication curve. It's a web-first pharmacokinetic visualiser that plots an estimated level and compares it against clinical-study patterns, with decent side-effect patterning on top.

What it can't do: anything body-composition related, no scan, and being web-first makes on-the-go logging clunkier than a native app.

GLPeak, Pep, MyTherapy and Cronometer

• GLPeak covers dose and side effects competently but doesn't touch body composition or a protein floor.
• Pep is a lightweight injection tracker — fine if a reminder is all you want, thin on symptom-to-dose intelligence.
• MyTherapy is a general medication-reminder app, not GLP-1-shaped; it'll nag you to take the shot but doesn't understand the weekly cycle, injection sites, or macros.
• Cronometer is the deepest nutrition tracker here — excellent fiber and micronutrient data — but it isn't dose-aware and has no floor logic. It'll tell you how much protein you ate; it won't tell you it wasn't enough.

Tiro

Full disclosure: Tiro is our app, and it's in this table on the same terms as everyone else. Where it's strongest is the two gaps nobody else fills — it derives body-fat percentage and measurements from a phone 3D body scan, and it makes a personalised protein floor the headline number instead of burying protein under a calorie budget. Its dose model is a real Bateman curve with a titration ladder, and the injection-site heatmap remembers your last several sites and flags overuse.

Who is it not for? If all you want is a bare dose reminder, a lighter app like Pep or Shotsy's free tier does that fine, and you don't need the scan. Tiro earns its place when fat-versus-muscle and protein actually keep you up at night. See how Tiro works.

Best free GLP-1 tracker apps — what each free tier actually unlocks

"Free" means very different things across these apps, and the paywalls hide in inconsistent places. Here's the honest map of what a glp-1 tracker app free tier tends to unlock:

• Shotsy has the most generous free tier for the basics — logging shots, reminders, and a running history without hitting a wall early. It's the default free pick for a glp-1 injection tracker app.
• Glapp is free and web-based; the medication-level curve is the draw, and you don't pay to see it.
• MeAgain, GLPeak and Pep are freemium — expect the deeper features (extended history, some analytics, AI features) behind a subscription.
• MyTherapy and Cronometer are broadly free, but neither is built for the GLP-1 weekly cycle.
• Tiro's free tier keeps the protein floor open, because a floor you can only see after paying isn't much of a floor.

The trap to watch for is dose history or injection-site rotation being paywalled after a short window — a best app to track weight loss injections should let you see your own past shots for free.

Best free Ozempic tracker for iPhone

If you're on iPhone and want a free ozempic tracker app free iphone option, the two things to check are Apple Health sync and where your data lives. Shotsy syncs with Apple Health and covers the free basics well. For privacy, look for apps that keep sensitive logs on-device rather than shipping everything to a server — an app that stores your dose diary locally and only syncs what you opt into is the safer default. As always, check the current app description for what the free tier includes before you rely on it.

Best semaglutide & tirzepatide tracker app (built around your weekly cycle)

Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) are once-weekly injections, and the whole point of a good semaglutide tracker app is that it's shaped around that weekly rhythm rather than a daily pill reminder.

Semaglutide has a long half-life — roughly a week — which is what makes once-weekly dosing possible, per the FDA prescribing information for Wegovy and Ozempic. Plasma levels rise after the shot and then taper across the week rather than spiking and crashing daily. Practically, that means the days right after your injection can feel different from the days before your next one, and timing your protein, hydration, and symptom logging to that cycle gives you a far clearer read than logging in a vacuum.

A tirzepatide tracker app needs the same weekly framing plus a titration ladder, because both semaglutide and tirzepatide are stepped up gradually. An app that models an estimated medication level — rather than drawing a decorative curve — lets you line up how you feel against roughly where you are in the cycle. Tiro computes an individual curve and a titration schedule; Glapp shows a generic version for free. Either beats a flat reminder.

Set dose + titration reminders that match your weekly cycle in Tiro if you want the schedule to track your actual ladder. None of this is dosing advice — how and when you step up is your prescriber's call.

Best GLP-1 side-effect tracker app

Nausea is the most common gastrointestinal side effect of GLP-1 medications, and it typically eases once you've settled on a stable dose, according to the FDA prescribing information for these drugs. Titration — starting low and stepping up slowly — is the main tolerability lever clinicians use, which is exactly why a glp-1 side effect tracker app is more useful when it understands your dose timeline.

A flat symptom list tells you that you felt sick. A good tracker tells you that you felt sick two days after a dose step-up, which is a pattern you can actually take to a clinician. That's the difference between Pep's basic logging and an app that pins symptoms to the dose curve. Layer in general mitigation nudges — hydration and fiber for constipation, smaller protein-forward meals for nausea — and the log becomes something you act on.

Two hard rules here. First, these mitigation ideas are general and educational, not a treatment plan. Second, "is this normal?" is a question for your prescriber, not an app — especially for severe or persistent symptoms. Use the log to bring better information to that conversation. In Tiro you can log a side effect and get mitigation tips, with the reminder to escalate anything worrying to your clinician.

Best Mounjaro tracker app (UK)

Mounjaro (tirzepatide) is the dominant weight-loss brand in the UK, so a mounjaro tracker app uk is really a tirzepatide-cycle tracker with a titration ladder that matches the UK step-up schedule. Zepbound, the other tirzepatide brand, is US-only — UK readers will only see Mounjaro.

Whether you're prescribed through the NHS or a private clinic — Voy, Numan, CheqUp, SimplePharmacy and similar services are common private routes — the app requirements are the same: log the weekly shot, follow the dose ladder, rotate injection sites, and record side effects against the cycle. What differs is cost and follow-up cadence, and a tracker that keeps a clean dose-and-symptom history is genuinely useful when you have a clinic review or a dose-change decision coming up. For UK clinical framing on GLP-1s and eligibility, the NHS and NICE are the authoritative sources; your prescriber or pharmacist is who decides your ladder. Dose reminders & titration ladder tracking works the same on Mounjaro as on any tirzepatide plan.

The gap almost no tracker fills: is it fat or muscle?

This is the part every self-graded app skips. When you lose weight fast — which is common on a GLP-1 — not all of it is fat. Body-composition sub-analyses of GLP-1 and caloric-restriction trials suggest that, in some studies, roughly a quarter to a third of the weight lost can be lean mass, though the exact share varies by study, population, and how much resistance training and protein were in the picture. (Treat that as a hedged range from body-composition sub-analyses, not a fixed figure.) Muscle is metabolically valuable, so protecting it matters.

The scale can't tell you the difference, and neither can an app that only stores a weight number. Even the apps that added body-fat fields in 2026 just give you an empty box to type a number you measured somewhere else. That's not measurement — it's transcription.

Two things actually address the muscle question. First, deriving body composition rather than typing it: a phone 3D body scan and progress photos can estimate body-fat percentage and track measurements over time, so you see the fat-versus-muscle trend without a DEXA or a smart scale. Second, a protein floor instead of a calorie ceiling. When appetite crashes, the risk isn't overeating — it's under-eating protein. Guidance for preserving muscle during weight loss converges around 1.2 to 1.6 grams of protein per kilogram of body weight per day (versus roughly 0.8 g/kg for a sedentary baseline), with about 20 to 40 grams per meal to support muscle-protein synthesis — a range reflected in the ISSN position stand on protein and in dietetic guidance from bodies like the British Dietetic Association. A calorie budget is the wrong tool for this problem; a floor you're told to hit is the right one.

This is the information-gain core, so keep it in perspective: it's educational. Confirm your own protein target with a registered dietitian, especially if you have kidney concerns or other conditions.

Prove it's fat, not muscle — track your body-fat % with a 3D body scan and your daily protein floor in Tiro. More on the reasoning in how much protein to protect muscle on GLP-1 and tracking GLP-1 progress beyond the scale.

Which GLP-1 tracker should you pick?

Pick by your biggest challenge, not by whichever app shouts loudest:

• You just want the dose habit to stick → Shotsy. Free, polished, fast.
• You want one app that does a bit of everything → MeAgain.
• You want to see your medication curve for free → Glapp.
• You're worried about muscle loss and want a protein floor plus fat-vs-muscle proof → an app built around body scanning and a protein floor, like Tiro.

Not everyone should pick the same app, and that's the honest answer. The neutrality is the point.

FAQ

What is the best free GLP-1 tracker app? Shotsy has the most-used free tier for basic injection logging and reminders, and Glapp is a strong free medication-curve option. Free tiers differ a lot on what they paywall — check whether dose history, injection-site rotation, and protein tracking are included before you commit. Tiro keeps its protein floor in the free tier.

Is there an app to track Ozempic or Wegovy injections and side effects? Yes — most GLP-1 companion apps log injections and side effects. The differentiator is whether a side effect is tied to your dose day and weekly cycle, which makes patterns visible. Any "is this normal?" question still belongs with your prescriber.

Does any GLP-1 app tell you if you're losing muscle instead of fat? Most only let you type in a body-fat number from an external device. Tiro estimates body-fat percentage and measurements from a phone 3D body scan plus progress photos, so you can watch the fat-versus-muscle trend without a DEXA or smart scale. Body-composition sub-analyses suggest a meaningful share of weight lost can be lean mass, which is why protein intake matters.

How much protein should I eat on a GLP-1? Guidance for protecting muscle during weight loss converges around 1.2 to 1.6 grams per kilogram of body weight per day (versus roughly 0.8 g/kg sedentary), with about 20 to 40 grams per meal. This is educational, not a prescription — confirm your target with your prescriber or a registered dietitian.

What's the best Mounjaro tracker app in the UK? Any app with a proper titration ladder and weekly-cycle modelling works for Mounjaro (tirzepatide), the dominant UK weight-loss brand. NHS or private-clinic users (Voy, Numan, CheqUp and similar) should look for dose-ladder and injection-site tracking rather than a plain reminder.

Is Shotsy or MeAgain better — and what are the alternatives? Shotsy is best for a free, dose-focused habit; MeAgain is the most complete all-in-one. Both share the same gap — they log weight and let you type in body fat, but they don't measure body composition for you or enforce a protein floor. If that gap matters, look at an alternative built around body scanning and protein.

Sources

• FDA prescribing information for Wegovy and Ozempic (semaglutide) — dosing, weekly administration, half-life, and common side effects.
• FDA prescribing information for Mounjaro and Zepbound (tirzepatide) — dosing and titration schedule.
• ISSN (International Society of Sports Nutrition) position stand on protein and exercise — protein intake ranges and per-meal distribution for muscle-protein synthesis.
• British Dietetic Association (BDA) — dietetic guidance on protein and weight management (UK).
• NICE and the NHS — UK clinical framing and eligibility guidance for GLP-1 medications.
• Body-composition sub-analyses of GLP-1 and caloric-restriction weight-loss trials (e.g., STEP and SURMOUNT programme reports and related peer-reviewed analyses) — lean-mass share of weight lost.

This article is for information only and is not medical advice. Talk to your prescriber or a registered dietitian before changing your diet or medication. Tiro is a tracking companion, not a treatment, and does not change clinical outcomes.