Shotsy Is a Great Shot Logger. It Just Can't Tell You If You're Losing Muscle.

This article is for information only and is not medical advice — talk to your prescriber before changing your medication, diet, or exercise. Disclosure: Tiro is our app, and this review reflects hands-on testing of Shotsy alongside several other GLP-1 trackers.

Shotsy is one of the best free GLP-1 shot trackers you can install right now: polished dose logging, a medication half-life curve, a clean daily weight graph, a 4.8-star rating, and 100k+ downloads. Its limitation is structural, not a bug. Shotsy charts the weight you lose but not whether that weight is fat or muscle. Body-composition sub-analyses of GLP-1 trials attribute a meaningful share of the weight lost, in some studies roughly a quarter to a third, to lean tissue. So if muscle matters to you, pair or replace Shotsy with a tracker that measures body composition and protein.

What is Shotsy, and who is it for?

Shotsy is a weekly-injection logger built for people on GLP-1 medications: semaglutide (Ozempic, Wegovy, Rybelsus), tirzepatide (Mounjaro, Zepbound), and, as of its more recent "Maintenance Mode" updates, oral GLP-1 pills too. You log each shot, get a next-dose reminder, rotate injection sites, and watch your weight trend over time.

It is genuinely good at what it sets out to do. If you searched "shotsy app" to find out what it is before installing, here's the short version: it's a focused, free-first tracker for the medication side of a GLP-1 journey. It is not a coaching program, a food scanner, or a body scanner. Knowing that boundary is the whole point of this review, because the gap it leaves open is exactly the one that matters most if you care about the quality of your weight loss, not just the number on the scale.

What Shotsy does well (the honest part)

Credit where it's due. Shotsy earns its ratings.

The free core tier covers the essentials most people actually need: dose logging, dose reminders, side-effect notes, a weight trend, and basic nutrition logging. The interface is clean and fast, which matters for something you'll open every week for months. Its signature premium feature is the medication-level curve, an estimate of how much drug remains in your system between injections, which helps people visualize why they feel different on day two versus day six.

The third-party validation is real: a 4.8-star App Store rating across a large review base and 100k+ downloads is not something you fake. For someone who just wants a reliable shot log and a weight chart, Shotsy is a legitimately strong pick, and this review isn't a hit piece. The critique that follows is about completeness, not competence.

Pricing: is Shotsy free, and what does premium cost?

Shotsy is free to download, and the core logging features stay free. Premium is reported by third parties at about $49.99/year (raised from an earlier $29.99), with a monthly option around $9.99, unlocking extras like the medication-level curve and Apple Health integration. Treat those numbers as third-party-reported rather than a fixed guarantee, subscription pricing changes, so confirm the live price in the App Store or Google Play before you subscribe.

The one thing Shotsy can't tell you: fat vs. muscle

Here's the wedge, stated plainly: a weight graph cannot tell you whether the pounds you're dropping are fat or muscle. That's not a Shotsy failing specifically, it's a limitation of any tool that only tracks bodyweight. But it's the question that determines whether your results are the kind you want to keep.

This isn't hypothetical. Body-composition sub-analyses of the major semaglutide trials, including work tied to the STEP 1 program (the trial published in the New England Journal of Medicine, 2021) and related studies, found that a substantial share of the weight lost was lean mass rather than fat. Reported across these body-composition sub-studies, the lean-mass share lands in the range of roughly a quarter to a third, and some analyses put it higher.

Two things keep this honest. First, losing some lean mass is normal in any significant weight loss, GLP-1 or not, because your body sheds supporting tissue as it shrinks. Second, later work suggests the lean-mass decline is often front-loaded and can stabilize, and functional measures don't always drop in step with the scan numbers. So the takeaway isn't "GLP-1s destroy your muscle." It's more useful than that: muscle loss is a real, measurable variable, and Shotsy's weight graph is blind to it by design. You can't manage what you can't see.

Prove it's fat, not muscle. Watch your body-fat percentage and measurements over time with a phone 3D body scan + body-fat % in Tiro, not just the scale.

Why muscle loss is trackable, and what a tracker should measure

The good news is that the two biggest levers for protecting lean mass are both trackable, and they're not medical interventions, they're daily habits your prescriber will likely already endorse.

Lever one: protein. During active weight loss, research and dietetic guidance point toward roughly 1.2 to 1.6 g of protein per kg of body weight per day, well above the general baseline of about 0.75 to 0.8 g/kg. Spreading it across meals, in the ballpark of 20 to 40 g per meal, supports muscle-protein synthesis. The International Society of Sports Nutrition (ISSN) position stand on protein and general clinical guidance both support elevated protein during weight loss. Ask your prescriber or a registered dietitian for your personal number.

Lever two: resistance training. Lifting or bodyweight work signals your body to hold onto muscle while you're in a calorie deficit. A tracker can't do your workouts, but it can help you protect the fuel that makes them count.

So what should a complete GLP-1 tracker actually measure? Three layers:

1. Protein against a personalized floor, not a calorie budget that quietly collapses when your appetite crashes on a higher dose.
2. Body composition — body-fat percentage, measurements, a 3D scan, and progress photos, so you can see fat-vs-muscle instead of guessing.
3. Dose-timed side effects, because if nausea wrecks your appetite on shot day, you'll miss your protein floor exactly when muscle is most at risk. Nausea is the most common GI side effect on GLP-1s and typically eases once you settle on a stable dose; titration is the main tolerability lever, per the FDA prescribing information for these drugs. Any change to your dose is a conversation for your prescriber, not an app.

Shotsy tracks none of these three the way they need to be tracked.

The Shotsy alternative that closes the gap: Tiro

Tiro is a GLP-1 companion and tracker built around the body-composition question Shotsy leaves open. To be clear about what it is and isn't: Tiro is a tracker, not a treatment. It doesn't change your clinical outcome, and it won't "prevent muscle loss." What it does is make protein and body composition visible, so you and your prescriber can watch the trend. Here's how each gap maps to a shipped feature.

• Protein-floor hero. Instead of a calorie target, Tiro sets a daily protein floor from your body weight and shows a running per-meal bar so you know, at a glance, whether you've hit it. Track your protein floor meal by meal, especially on the days appetite is low.
• 3D body scan + body-fat % + measurements + progress photos. This is the non-scale evidence layer. A phone 3D body scan + body-fat % trend lets you watch composition move, not just total weight, which is the only honest way to answer "is this fat or muscle?"
• Dose-timed symptom log with mitigation tips. Log a side effect against your actual dose day and titration step, and get an "is this normal?" read plus practical hydration and fiber nudges. Log this side effect and get mitigation tips rather than staring at an undifferentiated list.
• Real PK/titration math, injection-site rotation, and next-dose reminders. Tiro keeps the shot-logging strengths you'd expect, plus a proper pharmacokinetic curve and an injection-site rotation heatmap. Set titration + next-dose reminders so the medication side stays as tidy as it is in Shotsy.

Keep Shotsy for the shot log if you love it, add Tiro for the body-composition layer. See how Tiro works.

Other Shotsy alternatives, briefly

To keep this fair: Shotsy isn't your only option. MeAgain bundles food, side effects, and progress, and its strength-benchmark proxy is the closest any mainstream app gets to composition, but a strength benchmark still isn't a body-fat measurement. Regimen leans into symptom-and-outcome correlation. DoneDose and Pep cover dose logging and reminders competently. None of them measures body-fat percentage. If body composition is your priority, that's the line that separates them.

Shotsy vs. Tiro: side-by-side

Scored on capability, not marketing. Shotsy wins on maturity and install base; Tiro wins on the body-composition and protein layers.

If all you need is a clean weight graph and a reliable shot log, Shotsy is excellent and free. If you want to see whether your loss is fat or muscle, that's a different tool.

UK note: Mounjaro-first

For UK readers, the dominant weight-loss brand is Mounjaro (tirzepatide), available both through the NHS under specific eligibility criteria and via private clinics such as Voy, Numan, and CheqUp. Zepbound isn't sold in the UK. The titration ladder and side-effect picture are broadly the same, and NICE guidance and the NHS are your reference points for eligibility and safety. Whichever brand you're on, the fat-vs-muscle question is identical, and so is the case for tracking protein and body composition. Always follow your prescriber's or GP's guidance on dosing.

The verdict

Shotsy is a genuinely good, genuinely free GLP-1 shot logger. If a clean weight graph and a solid dose log are all you need, keep it, there's no shame in a tool that does one job well.

But a weight graph can't answer the question that decides whether your results last: is this fat, or is it muscle? If protecting lean mass matters to you, you need a body-composition and protein-floor layer that Shotsy simply doesn't have. That's the gap Tiro was built to close, as a tracker that helps you and your prescriber watch the trend, never as a treatment that promises an outcome. And as always: talk to your prescriber before changing your medication, diet, or exercise.

FAQ

Is the Shotsy app free? Yes. Core dose, side-effect, weight, and nutrition logging are free. A premium tier (reported at about $49.99/year, or roughly $9.99/month) unlocks extras like the medication-level curve and Apple Health sync. Verify current pricing in-app before subscribing.

How much does Shotsy cost? Shotsy is free to download and use. Premium is reported by third parties at about $49.99/year (up from $29.99), with a monthly option around $9.99. Treat these as third-party-reported figures and confirm the live price in the App Store or Google Play.

Does Shotsy track muscle loss or body fat? No. Shotsy charts total body weight, which can't separate fat from lean mass. To see body composition you need body-fat percentage, tape measurements, a 3D body scan, or a clinical scan such as DEXA.

What's the best Shotsy alternative for body composition? Tiro adds a protein floor, a phone 3D body scan, and a body-fat-percentage trend, so you can watch composition rather than just the scale. MeAgain and Regimen add symptom correlation and strength benchmarks. Choose based on whether you want body-composition evidence or charts alone.

How much protein should I eat on a GLP-1 to protect muscle? Research points to roughly 1.2 to 1.6 g/kg/day during active weight loss, above the general baseline of about 0.8 g/kg, alongside resistance training. Ask your prescriber or dietitian for your personal target; a tracker helps you hit a daily floor.

Is Shotsy or MeAgain better? Shotsy is the more mature, chart-heavy free shot logger. MeAgain bundles food, side effects, progress, and a strength-benchmark proxy. Neither measures body-fat percentage, so pick based on the feature you'll actually use.

Sources

• New England Journal of Medicine (2021) — STEP 1 trial of semaglutide for weight management, and its body-composition sub-analysis.
• SUSTAIN 8 and related semaglutide body-composition analyses (peer-reviewed).
• FDA prescribing information for Wegovy (semaglutide) and Zepbound (tirzepatide) — side-effect profile and titration.
• International Society of Sports Nutrition (ISSN) position stand on protein and exercise.
• NICE guidance and the NHS — UK eligibility and safety context for Mounjaro (tirzepatide).
• Apple App Store listing for Shotsy (rating, downloads); third-party pricing reports (GLP3 Planner, Regimen).

Related reading: best GLP-1 tracker apps compared · how much protein to protect muscle on a GLP-1 · GLP-1 side-effect tracker (dose-timed)

This article is for information only and is not medical advice — talk to your prescriber before changing your medication, diet, or exercise.