Peptide Stack Tracker: One Weekly Grid for Every Compound
A peptide stack tracker shows several compounds, each with its own schedule and vial, in one view. PepTrac for iPhone lays protocols side by side on a weekly grid, gives each compound its own vial and level curve, and never combines curves into one number. It records what you enter and does not check interactions or suggest combinations.
What is a peptide stack?
A peptide stack means more than one compound tracked in the same period. It is a scheduling word, not a medical term, and this page makes no suggestion about which compounds belong together. Be careful with the idea of safe combinations. The Zepbound prescribing information says that coadministration with other tirzepatide-containing products or with any GLP-1 receptor agonist is not recommended.[1] For BPC-157 and TB-500 the FDA says it has identified no, or only limited, safety information for BPC-157's proposed routes, and no human exposure data for the TB-500 fragment.[3] A tracker cannot fill those gaps. What it can do is show, in one place, everything you have logged, so you and your prescriber can see what was taken, when, and from which vial. PepTrac does not check interactions and does not recommend any combination. Treat the app as a record, and ask a clinician or pharmacist about the compounds themselves.
Why is a stack harder to track than one compound?
Each added compound adds its own frequency, its own vial, and its own unit math. One compound might be injected daily, another on weekdays only, another every other day, another twice a week, and another once a week. Every vial has a different size and a different water volume, so the same 0.1 mL draw can mean a different amount of each compound. A single pill-style reminder cannot hold all that. Memory fails first at the edges: which vial did Tuesday's dose come from, how many days of supply are left, and did the weekly one already happen. A stack tracker solves this by giving each compound its own record and then rolling them into a shared view for today. PepTrac supports daily, weekdays, every other day, twice a week, and weekly frequencies, and it keeps a separate vial for each compound with its own fill percentage and days left.
How does a weekly grid help with several compounds?
A weekly grid puts one row on the screen for each compound and one column for each day, so a glance shows what is scheduled and what is already logged. Today's column is your checklist. In PepTrac the grid sits on the Track tab, below the vial cards, and it shows what you have logged. You can move between weeks, and you can arrange the compounds in the order you prefer. The table below reproduces the layout of the Track tab screenshot used on the PepTrac home page, which shows four compounds. It is a layout example only and does not suggest taking these compounds together. The value of the grid is practical. A weekly compound and a daily one stop competing for attention, and a gap in any row is visible without opening anything. Reminders can be set for each compound separately.
| Compound | Frequency | Days marked in the week | Vial status shown |
|---|---|---|---|
| Retatrutide | Weekly | Thursday | 10 mg vial, 60% left, 14 days |
| BPC-157 | Daily | All seven days | 5 mg vial, 65% left, 12 days |
| Semaglutide | Weekly | Monday | Own vial card with fill and days left |
| Tesamorelin | Weekdays | Monday to Friday | Own vial card with fill and days left |
Can level estimates be added together?
No, and PepTrac never does it. Each curve is in that compound's own relative units, scaled so that a single dose peaks at its logged amount in milligrams. A sum of two such curves has no meaning, because the compounds differ in potency, half-life, and what the numbers represent. Two real outputs show the mismatch. For an example 0.25 mg semaglutide entry, the estimate on day 7 is 0.164, with a range of 0.138 to 0.184. For an example 2.5 mg tirzepatide entry, it is 1.14 on day 7, range 0.89 to 1.34. The two numbers cannot be compared or added, since they are on different scales. These amounts are arithmetic examples, not dose recommendations. The shaded band is a sensitivity range, not a statistical confidence interval, and the curves are estimates, not lab results. PepTrac therefore charts each compound separately over 7, 30, or 90 days.
How do you keep several vials straight?
Keep one vial record per compound and let the app do the counting. In PepTrac each compound has a vial that drains as you log doses, with the percentage left and the number of days it will last. You can also record sealed reserve vials, and the app counts those in the supply. Each vial carries a reconstituted date that you enter. The FDA advises discarding a multi-dose vial within 28 days after first use, even if medication remains, because contamination risk rises after that time.[2] PepTrac does not count down that period or flag a vial, so the days left it shows can run past 28 for a vial that still holds many doses. Your product's own label, or your pharmacist, decides how long a particular vial may be kept. Write the date on the vial as well, and recheck it before each draw.
How do you avoid reusing one injection site across compounds?
One site history should span every dose, whatever the compound. PepTrac records the injection site for each dose you log, and Home marks the last site on a body map across every compound with your three most recent doses, so a site used for one compound this morning shows up when you log another. PepTrac shows where you have injected, but it does not recommend the next site or say how often to rotate, and it is not medical advice. Questions about technique, site choice, or reactions belong with your clinician or pharmacist. The dose history also names the site beside each entry. A shared history helps most when two compounds are injected on the same day, because without one it is easy to repeat a site without noticing. For a deeper look at site choice, see the guide to injection sites.
Frequently asked questions
How many compounds can I track in PepTrac?
Several. Each compound has its own schedule, vial, and level curve, and the weekly grid shows them side by side. This site does not state a fixed maximum, so check the app if you plan to track many.
Does PepTrac check for interactions?
No. PepTrac records what you enter and does not check interactions, warn about combinations, or suggest a stack. Ask a clinician or pharmacist about any combination.
Can each compound have its own reminder?
Yes. Reminders are set per compound, so a weekly dose and a daily dose can each prompt you at the time that fits. The Home tab also shows a countdown to your next dose.
Can I reorder my compounds?
Yes. You can arrange the compounds in the order you prefer, so the vial cards and the weekly grid list the ones you use most first.
Does the AI chat see my whole stack?
PepTrac AI chat reads the data you have logged in the app, such as doses, protocols, and weight. It can log a dose only after you confirm it. It does not replace a clinician.
Sources
- DailyMed, National Library of Medicine (Eli Lilly). Zepbound (tirzepatide) injection prescribing information. Accessed October 3, 2026.
- U.S. Food and Drug Administration. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Accessed October 3, 2026.
- U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Accessed October 3, 2026.
Written and maintained by the team that builds PepTrac. Every calculator on this site runs the same tested math as the app. Read how we research, cite, and update pages in our editorial policy.
