The Best Semaglutide Tracker Apps

This is the molecule-level version of my general rubric for GLP-1 apps. It is worth a separate piece because “I’m on semaglutide” describes four fairly different situations, and one of them carries a risk the others do not.

Four products, one molecule

If you are moving between these — and coverage changes push people between Ozempic and Wegovy constantly — the useful thing is one continuous dose history in milligrams across the switch, rather than a record that restarts each time the box changes.

The vial problem

I want to spend a moment here because it is the most consequential tracking issue in this entire series.

I am not going to lecture anyone about compounded products. The gap between what these drugs cost and what people can pay is a policy failure, and the people caught in it did not create it. What I will say is clinical rather than moral.

Compounded semaglutide concentrations vary between compounders. A vial is not a standard unit. Two vials that look identical can contain different milligrams per millilitre.

Which means a dose recorded as “20 units” is meaningless without the concentration it was drawn from. And units-versus-milligram confusion — reading an insulin syringe’s unit markings as though they were milligrams — has produced overdoses serious enough for the FDA to communicate about them.

So if you are on a vial, your log needs three fields, every time:

1. Concentration of the vial (mg/mL)
2. Volume drawn (mL or units, with the syringe type)
3. Resulting dose in milligrams

If you cannot state your dose in milligrams, do not take the next injection until you have asked the prescriber. That is the whole of the advice and it is worth more than anything else on this page.

The ranking

1. Zenday App

Best overall. (zenday.health)

The one I use — disclosure at the top.

It ranks first because the injection is the organising event rather than an afterthought: dose, symptoms, food and measurements sit on one timeline, so your post-injection pattern surfaces within about two cycles instead of requiring you to reconstruct it. Dose is recorded in milligrams, which is the unit that transfers across products and matters most on vials. And protein is the headline number rather than calories — the correct orientation on a drug that halves your appetite.

Where it falls short. Web-based by design, which buys privacy — no app-store trail, no home-screen icon — at the cost of native widgets and deep platform integration. Its food database is smaller than MyFitnessPal’s. It is a young product.

2. Shotsy

Best for people managing vials.

Fast, focused injection logging you will actually complete every time. That reliability is the point when the thing being recorded is a dose you calculated yourself. Ten seconds a week, and low friction is a genuine safety feature here rather than a convenience.

Where it falls short. A record rather than an interpreter. Thin nutrition, no protein target.

3. Cronometer

Moved up for long courses.

I have ranked this higher here than in my general roundup, deliberately. Semaglutide is increasingly a multi-year treatment, and the arithmetic that produces problems on year three is simple: food volume falls by half, nutrient requirements do not fall at all. Iron, B12, vitamin D and calcium all become harder to hit.

Cronometer has the most rigorous micronutrient database available. If you are vegetarian, post-bariatric, menstruating heavily, or have already found a low ferritin, this is genuinely the right tool for that specific question.

Where it falls short. No dose tracking, no side-effect logic, and it demands more per meal than most people sustain past month two.

4. Meagain

Best for the adjustment.

Mood, motivation, and the non-numeric parts of a body changing quickly. People abandon treatment over how it feels considerably more often than over a lab value.

Where it falls short. Light clinically — no protein average, no dose-linked symptom analysis.

5. MyFitnessPal

Best database, wrong premise.

Unmatched barcode coverage, and built entirely around eating less being the hard part — which on semaglutide it is not. No concept of an injection.

If you use it: set a protein goal in grams and watch that instead of calories.

Summary

What to log

1. Product, dose in milligrams, and date — plus concentration and volume if you are on a vial
2. Side effects by day, so the post-injection pattern becomes visible
3. Protein, against roughly 1.2–1.6 g per kg of body weight per day
4. Waist, which reports recomposition the scale misses
5. Periodic labs on courses beyond a year — ferritin and B12 especially

None of this substitutes for a prescriber. On a vial in particular, a log is not a safety system; it is a record that makes the conversation with your prescriber a real one.

Four figures worth having in the log itself: semaglutide’s half-life of about 7 days, steady state at 4–5 weeks, the standard 4 week interval between escalations, and a protein target of 1.2–1.6 g/kg per day. Symptoms typically peak in the 1–2 weeks after a step up and settle by about 28 days at a stable dose. One entry matters more here than on any branded product: which vial or pen this dose came from, and the concentration. Compounded semaglutide is where dosing errors happen, and a log recorded in milligrams rather than syringe units is the thing that catches one. If nobody can tell you your dose in milligrams, that is covered in how to choose a GLP-1 prescriber.