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Peptiday

GLP-1 tracker for iPhone

Never wonder if you took this week's shot.

Peptiday tracks tirzepatide, semaglutide and other GLP-1 medicines. Log your shot from the reminder, rotate sites without thinking, and compare your weight and sleep before and after each step.

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$79.99 once, or 7 days free on yearly for new subscribers. No account.

Tirzepatide

Mondays · 9:00 AM

  1. 9Mon
  2. 10Tue
  3. 11Wed
  4. 12Thu
  5. 13Fri
  6. 14Sat
  7. 15Sun
9:04AM
Tirzepatide · 5 mgLeft thigh · logged MondayLogged

Next dose: Monday, Nov 16, from your own schedule. Example records.

Estimated tirzepatide level at about 70 percent of the steady peak, marked as a model estimate
An estimated level from your logged doses, labeled as an estimate.
Sleep before and after October 22: 6 hours 46 minutes against 7 hours 10 minutes, observed, not proof of cause
Sleep before and after a protocol change, with everything else that changed.

Weekly reminders that stay quiet

Log, snooze or skip from the notification. The lock screen says “Dose due” and nothing more, unless you choose otherwise.

Site history

Every site you use, listed by when you last used it. Rotating between belly, thigh and arm takes no memory.

Your full history

Every shot, skip and amount change, kept on your iPhone. Export your doses as a CSV for your next appointment.

Progress

See what changed after each step.

When your prescriber changes your dose, Peptiday lines up your Apple Health weight, sleep, HRV and resting heart rate from before and after. You see both windows, how many days had data, and what else changed at the same time.

It shows what changed, never why. That part is a conversation with your clinician.

Before

206.7 lb

6 of 14 days

After

203.4 lb

6 of 14 days

−3.3 lbClear difference

EXAMPLE · Sample data

Estimated levels

Why a weekly shot builds up.

Tirzepatide has a label half-life of about 5 days and Semaglutide about 7 days. Each shot adds to what's left of the last one. Peptiday draws that from your own log, labeled as an estimate.

Illustration relative to the modeled peak. The half-life comes from the label and absorption is assumed. It isn't a blood measurement, so don't use it to choose amounts or timing.

Questions

Does it work with Ozempic, Wegovy, Mounjaro and Zepbound?

Yes. Search by brand or ingredient: typing Zepbound finds tirzepatide, and Wegovy finds semaglutide. You can also add any preparation yourself, including compounded ones, and enter exactly what your label says.

Will Peptiday tell me when to increase my dose?

No. Peptiday records the schedule your prescriber gave you. It never suggests a dose or tells you when to change one. When your prescriber changes it, you update the amount and Peptiday keeps the history.

Can I see how my weight changed after a dose change?

Yes. Peptiday compares your Apple Health data from before and after each change and shows how many days had data. You see every day, every measure you watch and what else changed in the same window. It shows what changed, never why.

Is there a free version?

No free plan. Lifetime is one payment of $79.99 with no renewals, and yearly starts with 7 days free for new subscribers. Every plan unlocks everything.