Best Peptide Tracker Apps for Dosing and Cycles (2026)

The best peptide tracker app is the one that keeps three things in sync: the reconstitution math, the vial inventory, and the dose log. When those drift apart, your records stop matching reality. By that test, our pick is Stackr, because it is a calculator and a tracker in one app, and it is free to download.

This is an educational, record-keeping comparison, not medical advice. Peptides are research compounds not approved for human consumption, and nothing here is dosing guidance. The point is simply which tool keeps the numbers clean.

Our pick: Stackr

Most apps marketed as peptide trackers are calendar reminders with a themed icon. Stackr is built around the math, so the number you calculate is the number you log. Concretely:

• Calculator and log in one. It runs the same reconstitution and mg-to-units math as the free reconstitution calculator, so a draw is logged at the exact units you measured.
• Vial-level inventory. It knows total mg, what you have drawn, and what is left, deducts each logged dose automatically, and warns you before a vial runs out.
• One-tap dose logging with automatic timestamps, injection-site rotation, and notes per dose.
• Per-peptide level charts from half-life modeling, so you see your week at a glance, not just the next reminder.
• 100+ compounds including GLP-1s like semaglutide and tirzepatide, plus growth-hormone peptides and healing peptides.
• Free to download (with an optional free trial of the premium features). Get the app here.

What makes a peptide tracker worth using

Whatever you pick, hold it to the same four-part standard. A real tracker ties these together so they stay consistent with each other.

• Vial inventory that tracks total peptide, amount drawn, and amount left.
• Concentration math linking mg, bacteriostatic water, and syringe units. Reconstitute a 10 mg vial with 2 mL and each unit on a U-100 syringe is 0.05 mg.
• A timestamped dose log that reflects what was recorded, not what was planned.
• Schedule-aware reminders that understand on and off weeks, not a generic daily ping.

Why not a spreadsheet or notes app

Concentration is where homemade tracking breaks. The same mg figure means a different number of units depending on how much water went in. A 5 mg vial in 1 mL is 5 mg/mL, so 0.25 mg is 5 units. The same 5 mg in 2 mL is 2.5 mg/mL, so 0.25 mg is 10 units. Notes and spreadsheets do not decrement a vial or re-run that math, so they drift the moment a vial changes. If you only need the math, the mg to units converter and the per-compound pages under peptides cover it on the web, free.

A short buying checklist

1. Can it store a vial with total mg, water volume, and amount left?
2. Does it convert mg to syringe units at that vial's concentration automatically?
3. Is logging a dose one or two taps, with an editable timestamp?
4. Do reminders understand cycles, not just daily repeats?
5. Can you see a chart of recorded doses over time?

Any tracker that passes all five keeps your records clean. Stackr was built to pass all five in one place. Decisions about whether, what, or how much to use are not the app's job. Those belong with a licensed clinician. See the disclaimer for the full framing.