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For your GLP-1 journeyMade for iPhone ↗

A little clarity. Every day.

Your progress.
Beyond
the scale.

Meet your GLP-1 companion for body scans, fat and muscle estimates, protein and pen days.

Download on the App Store (opens the App Store)Free pen tracking · Body & food scans with Plus
Currently listed as Tiro on the App Store
GLP-1

Less guesswork.
More living.

A companion for the whole you.
And everything between pen days.

01 / Know what’s changing PLUS

There’s more
to losing weight
than weight.

Your weight is one number.
Fat and muscle tell different stories.

If preserving muscle matters to you, follow estimated changes in fat and muscle as your scan history grows.

See how your body adds context ↗
Your scan estimatesFat & muscleTwo estimates. A fuller perspective.
Fat or muscle: two scans nine weeks apart, with the change split into fat and muscle and a trend line for each.
YOUR FAT & MUSCLE TRENDS
Authentic app screen · example data

Estimates need sufficient scan history: at least 21 days between valid scans and 2.5 kg of weight change for the loss split. Small muscle changes may be shown as steady.

A new perspective PLUS

See what
the scale can’t.

A fitted 3D view.
Your measurements, over time.

Scan your body and follow your measurement history. Estimates add context to the number on your scale.

Explore your measurements ↗
ChestWaistHips
01 / Your body, in perspective02 / Follow the measurements03 / Your measurements, in view

From a scan
to your story.

Body scan: a 3D body model with measurements for shoulders, chest, upper arm, forearm, waist, hips, thigh and calf.
YOUR SCAN, IN PENSDAY
Authentic app screen · example data

Every body has a story

More than
one measurement.

Eight supported measurements, from shoulders to calves. Availability depends on the scan and the information you provide.

  • 01Shoulders
  • 02Chest
  • 03Upper arm
  • 04Forearm
  • 05Waist
  • 06Hips
  • 07Thigh
  • 08Calf

Your body scan stays on your phone. Body-scan processing happens on device. Food recognition uses remote processing.

A scan gives you estimates, not a clinical measurement. Follow your history and discuss your progress with your clinician.

Download on the App Store (opens the App Store)
Explore your Body overview
Pensday Body overview with weight, progress, Log weight and New scan.
Body scan: a 3D body model with measurements for shoulders, chest, upper arm, forearm, waist, hips, thigh and calf.
YOUR SCAN, IN PENSDAY
Authentic app screen · example data

02 / Your dose story Free

Make sense of
the week between.

Pensday lines up your weigh‑ins and side effects against your estimated medication level, week by week.

  1. 01The dose

    See what each dose did

    Your weight line, colored by dose: see how fast each step of the ladder moved your trend. Daily scale swings are mostly water, so Pensday reads your smoothed trend.

    Weight report: a weight trend line colored by dose (2.5, 5 and 7.5 mg) toward a goal line, and a list of what each dose did.
    Your weight reportInside Pensday · example app data

  2. 02The days between

    Dose vs. side effects

    Your estimated medication level, with the week’s side effects in lanes under it: nausea, heartburn, fatigue, food noise and more. Take them to your clinician.

    Patterns are estimated from what you log, not medical advice.

    Your patterns: an estimated medication-level curve for the week and side-effect lanes for nausea, heartburn, constipation, diarrhea and fatigue under it.
    Your weekly patternsInside Pensday · example app data

  3. 03The next pen

    Where the next pen goes

    Every pen is logged with its site, and Pensday recommends a fresh spot for the next one, so rotation takes care of itself.

    Injection sites: nine shots placed over two months, and the recommended next site, the right arm, a fresh spot never used.
    Your injection-site historyInside Pensday · example app data

Every pen. Every pattern.
All in one place.

Find your pen day

03 / Built around your pen day

What’s your
pen day?

Shot day, jab day, injection day.
On a weekly GLP-1, one day anchors your week. Make it yours.

A woman reaches for her pen by the door, with a shot-day reminder on her phone.
A little nudge.
Then on with your day.

Pick your pen day

A little routine. A little reassurance.

Your day.

Pick a day to see your week.

Set it once in Pensday and a reminder comes on your pen day, every week.

Get your pen-day reminder (opens the App Store)

Free in Pensday · for iPhone

See your estimated week

Estimated medication level (relative)

Your week appears here
Estimated medication level, drawn faintly until you pick a pen day.

Semaglutide peaks 1 to 3 days after a dose; tirzepatide 8 to 72 hours.

Estimated relative level that illustrates published half-lives. It is not a measurement or medical advice.

See your first weeks in the dosage plotter
See your reminder in Pensday

Every pen, logged.
Your next one, in view.Example screens from the app.

Shots tab with logged pens, dose countdown, streak and injection sites.
Your pens
Dose and Schedule: a weekly reminder at 8:30 AM on the chosen weekday, and the next dose in 18 hours.
Your reminder

04 / Everyday nourishment

Keep protein
in the picture.

Snap a meal and Pensday logs it, protein included.

A little more context for your everyday routine. Scan, search or use your voice to log food.

  1. 01
    Scan your meal

    Start with a photo.

  2. 02
    Review the estimates

    Check what goes into your log.

  3. 03
    See your day

    Keep meals and protein together.

From a meal to your day

A meal, logged.
A little more context.

Protein, calories, water and fiber. Keep the everyday in view, with your meals and their protein in one place.

Download Pensday on the App Store (opens the App Store)

AI food scanning is a Plus feature. Food recognition uses remote processing. Review the estimates before relying on your log.

See your daily intake in Pensday
Pensday Food tab: calorie bars, protein, calories, water and fiber.
Your daily intake · example app data
Meals and their protein, with Scan, Search and Voice logging controls.
Meals & proteinInside Pensday · example app data

Free and Plus

Start free.
Go further with Plus.

Everything you need to track a pen is free. Plus adds AI food scanning and the 3D body scan.

Choose your plan in the app. US prices. *Annual trial for eligible subscribers. See the App Store for local prices and subscription terms.

05 / Your routine

Your medicine.
Your routine.

Works with every GLP-1. Twelve medicines by name: pens, vials and pills, compounded included. Pick yours once, and every pen you log carries its name and dose.

  • Ozempicpen
  • Wegovypen
  • Wegovy pillpill
  • Mounjaropen
  • Zepboundpen or vial
  • Rybelsuspill
  • Trulicitypen
  • Saxendapen
  • Victozapen
  • Compounded semaglutidevial
  • Compounded tirzepatidevial
  • Retatrutidelog only
Log a shot: medication Mounjaro, dose chips from 2.5 to 15 mg with 7.5 mg selected, injection site Right Arm, and a how-you-felt slider.
Your medicine.
Logged in seconds.

Pensday is not affiliated with Novo Nordisk or Eli Lilly. Ozempic, Wegovy, Rybelsus, Saxenda and Victoza are trademarks of Novo Nordisk A/S. Mounjaro, Zepbound and Trulicity are trademarks of Eli Lilly and Company.

The people behind Pensday

A little more
peace of mind.

Who makes Pensday? Lightzone Solutions LTD. Our medical reviewer is Farnia Bahari, PharmD, and our editorial policy is public.

  • Medical reviewer

    Farnia Bahari

    PharmD

    An article she has reviewed names her at the top, with the date.

    About our reviewer

  • Editorial policy

    Clear sources. Careful words.

    How we source, update and correct our guides, and how medical review works.

    Read the editorial policy

  • The company

    Lightzone Solutions LTD

    The company behind Pensday, currently listed as Tiro on the App Store.

    About Lightzone

Better conversations, together.For clinics: Pensday helps patients share their patterns with their clinician.

Pensday for clinics

A few things you might wonder

Good
questions.

A clearer picture,
before you begin.

Why Pensday?

The name is the day you take your pen. Pick it once and the app plans the week around it: the reminder, the level, the patterns.

Is this the app that used to be Tiro?

Yes. Pensday is the new name for Tiro: the same app and App Store listing. The listing is still named Tiro while the rebrand rolls out.

What does Pensday track?

Every dose and injection site, your estimated medication level, side effects and weight, with a reminder on your pen day. Pensday Plus adds AI food scanning and the 3D body scan.

Which medicines does it work with?

Twelve, each by name: Ozempic, Wegovy (pen and pill), Mounjaro, Zepbound, Rybelsus, Trulicity, Saxenda, Victoza, compounded semaglutide, compounded tirzepatide, and retatrutide (log only).

What is free, and what does Plus cost?

Dose tracking, reminders, the estimated medication level, injection-site rotation, symptoms and weight are free. Pensday Plus adds AI food scanning and the 3D body scan for $59.99/year or $19.99/month (US). The annual plan includes a 7-day trial for eligible subscribers; the monthly plan has no trial. See the App Store for local prices and terms.

Are my body-scan photos private?

Yes. Normal body-scan processing happens on your phone. Optional research submissions require consent. Food recognition uses remote processing.

Does Pensday give medical advice?

No. Pensday is a tracking app. Your medication level and patterns are estimated from what you log, not measured: share them with your clinician, and talk to your prescriber about your dose.

Which devices does it run on?

iPhone. Download Pensday on the App Store.

A little planning goes a long way

Tools for the
week between.

Free calculators that run in your browser. Explore an estimated level.

All tools

  • 01 / YOUR WEEK

    GLP-1 Plotter

    You see your level now from your own shots, when it dips, and what a longer gap does.

    Open the tool
    YOUR ESTIMATED LEVEL

    The estimated medication level over six weekly pens of semaglutide 1 mg.

Pensday for iPhone

Your body.
Your protein.
Your pen day.

Follow your body changes. Keep protein in view. Log every pen, remember your next dose and see how your week unfolds.

Download on the App Store (opens the App Store)

Free to start

Body scanning and AI food scanning are included with Plus. Listed as Tiro on the App Store.

Pensday Body: fat and muscle estimates and their trends over time.
Your body changes, in viewFat & muscle estimates · example app data
See your journey and week in Pensday
Your Journey: day 64 and a 9-week streak over a September calendar of logged days, and the first week at 7.5 mg.
Your journeyInside Pensday · example app data
Dose and Symptoms: the estimated medication level after the last dose, with the peak marked, and symptom lanes for the week under it.
Your dose and symptomsEstimated levels · example app data