There are two kinds of GLP-1 app. The first is a logbook: it records the shot you already took, the weight you already lost, and the nausea you already felt. The second is a planner: it tells you what the week ahead is likely to look like so you can arrange your meals, workouts, and social calendar around it.
Almost every app in this category is the first kind. That's the gap this comparison is about — because the hardest part of being on semaglutide or tirzepatide isn't remembering what happened. It's not knowing what's coming.
How we compared them
Four criteria, chosen because each one changes a decision you actually make:
- Forecasting — does it tell you how the days ahead are likely to feel, or only chart the past?
- Muscle retention — does it actively coach protein and resistance training, or leave lean mass to chance?
- Shot logistics — reminders, injection site rotation, titration history.
- Privacy — where does your health data live, and who can read it?
Notes reflect what each app publicly described as of this writing; features and pricing move quickly in this category, so check the App Store listing before you commit.
Shotsy — the established all-rounder
Shotsy is the most widely used app in the category, and it earns that. Dose logging, smart scheduling, side-effect tracking, and estimated medication-level charts are all there, across semaglutide, tirzepatide, liraglutide, and dulaglutide. If you want the safest, most battle-tested pick, it's a reasonable default.
The gap: it is fundamentally a tracker. It records thoroughly, but it won't coach you toward keeping muscle, and its medication-level chart is a chart rather than a plan for the week. Shotsy
Regimen — generous free tier
Regimen covers the basics well: weekly shot reminders, injection site rotation, weight trends, and side-effect logging — and notably makes the medication-level curve available free.
The gap: seeing the curve is not the same as being told what to do with it. A line on a chart still leaves you to work out that Thursday is the day to skip the big dinner. Regimen
Myo — body composition focus
Myo leans into the fat-versus-lean-mass question, with DEXA/InBody scan import, muscle alerts, and protein targets. If you already scan your body composition regularly, that integration is genuinely useful.
The gap: it's built around measurements many people never take. If you don't have DEXA access, a lot of the value is out of reach.
LeanShot — protein-first
LeanShot pairs shot tracking with a daily protein goal and a muscle-preservation score — the closest competitor to the muscle half of what we do, and a solid choice if protein is your single priority.
The gap: no forecasting. Protein targets don't adapt to the fact that hitting 110g is trivial on a trough day and brutal on a peak day.
Phaze and MeAgain — adjacent picks
Phaze covers protein and hydration alongside weight tracking. MeAgain focuses on tracking plus medication access for US users. Both are competent logbooks; neither is trying to predict your week.
Feelforecast — the week ahead, plus your muscle
We built Feelforecast because we kept seeing the same two unanswered questions: how will I feel tomorrow? and is the weight I'm losing the right kind?
- A 7-day feel-forecast — your medication's estimated concentration curve turned into a day-by-day outlook: smooth days, tougher days, and your best training window.
- A muscle-retention coach — a daily protein target sized to your goal weight, three short weekly resistance sessions, and a weekly retention score.
- Shot logistics that remember for you — reminders, an 8-zone site rotation map, and a titration timeline.
- Private by architecture — no servers and no accounts. Your data stays on your device and in your private iCloud.
The honest trade-off: we're new. Shotsy has years of reviews and a much larger community. If social proof matters more to you than forecasting, start there.
What a GLP-1 tracker app should actually do
Whichever you choose, hold it to this checklist:
- Tell you something about tomorrow, not just yesterday.
- Take a position on muscle — protein targets and resistance training.
- Handle site rotation so you aren't reusing sore spots.
- Track titration without you keeping a separate note.
- Keep your health data off other people's servers.
- Never suggest a dose change — that's your prescriber's job.
The bottom line
If you want a mature logbook, Shotsy is the safe pick. If you want the medication curve for free, Regimen is generous. If you want to know which day this week will be your toughest and to be actively coached on keeping your muscle while the weight comes off, that combination is what we built Feelforecast to do.
Frequently asked
What is the best GLP-1 tracker app?+
It depends what you need. For all-round logging with a large user base, Shotsy is the most established. For a free medication-level curve, Regimen is generous. If you want the week ahead forecast plus active muscle-retention coaching in one app, that's the gap Feelforecast was built for. Most people should pick based on whether they want to record the past or plan the week ahead.
Are GLP-1 tracker apps free?+
Most are freemium: basic shot logging and reminders are free, and features like medication-level charts, insights, or coaching sit behind a subscription. Free tiers are genuinely usable in several apps, so it's worth trying before you pay.
Do I need a tracker app if my clinic already tracks my doses?+
Clinics track adherence and outcomes at appointment intervals. A tracker helps between appointments — remembering your injection site rotation, spotting which days you tend to feel worst, and keeping protein high enough to protect muscle. It supplements care; it never replaces your prescriber.
Medical disclaimer. This article is general education based on published pharmacology and manufacturer labeling — it is not medical advice, and it never recommends starting, stopping, or changing a dose. Individual responses to GLP-1 medications vary widely. Talk to your prescriber about your own treatment. See our Terms and Privacy Policy, or get in touch.