Medication reference

Mounjaro: FDA-sourced dosing, safety, and storage facts

A cited educational summary of the FDA-approved Mounjaro label, including dosing, safety, missed-dose, and storage information.

Dosley showing Mounjaro pen details

Mounjaro is the brand name for tirzepatide, a once-weekly injectable medicine prescribed alongside diet and exercise to improve blood sugar in adults and pediatric patients aged 10 years and older with type 2 diabetes. This page summarises the publicly available FDA-approved label as educational reference material. It does not give medical advice. If anything here differs from what your clinician has told you, follow your clinician.

At a glance

Active ingredient
Tirzepatide 1
Drug class
GIP and GLP-1 receptor agonist 1
Manufacturer
Eli Lilly and Company 2
FDA approval
May 2022 (NDA 215866) 3
Indication
Adjunct to diet and exercise for type 2 diabetes in adults and pediatric patients aged 10 years and older 1
Schedule
Once weekly, subcutaneous injection 1
Starting dose
2.5 mg once weekly 1
Maximum adult dose
15 mg once weekly 1
Missed-dose window
Within 4 days (96 hours) of the scheduled day 1
Storage
Refrigerated at 2–8°C; see the label for in-use room-temperature limits per pen format 1

Important safety information

Boxed warning

Tirzepatide causes thyroid C-cell tumors in rats. It is unknown whether Mounjaro causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans. Mounjaro is contraindicated in patients with a personal or family history of MTC and in patients with Multiple Endocrine Neoplasia syndrome type 2. 1

Contraindications

  • Personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). 1
  • Known serious hypersensitivity to tirzepatide or any of the excipients in Mounjaro. 1

Common side effects

  • Nausea ≈18% at 15 mg vs 4% placebo 1
  • Diarrhea ≈17% at 15 mg vs 9% placebo 1
  • Decreased appetite ≈11% at 15 mg vs 1% placebo 1
  • Vomiting ≈9% at 15 mg vs 2% placebo 1
  • Constipation ≈7% at 15 mg vs 1% placebo 1

Discuss benefits and risks with your healthcare provider before starting or continuing this medication.

Dosing and titration

Your prescriber decides every step on the schedule below. The summary here is for orientation while you log treatments - it is not a recommendation.

Treatment begins at 2.5 mg once weekly. After four weeks the prescriber may increase to 5 mg, then continue increasing in 2.5 mg increments after at least four weeks on the current dose, up to a maximum of 15 mg once weekly in adults. 1

The 2.5 mg starting amount is intended to help the body adjust before any glucose-lowering target is set. It is not the maintenance amount for most adults. 1

When you record a treatment in Dosley, you can attach the amount, the day, and any notes about how you tolerated it. The app does not change your schedule - it only records what your prescriber has set.

Injection sites and storage

Mounjaro is given by subcutaneous injection in the abdomen, thigh, or upper arm. Rotating sites between treatments is recommended in the prescribing information. 1

Pens should be kept refrigerated between 2°C and 8°C until first use. The room-temperature in-use period varies between the single-dose pen, multi-dose KwikPen, and vial formats - follow the limit printed on your packaging or in the patient leaflet. 1

Site tagging is optional. Turn it on and the entry screen shows which sites you used in the last few weeks.

Mounjaro and Zepbound

Mounjaro and Zepbound contain the same active ingredient. They are different brand names with different FDA-approved indications.

Tirzepatide is sold as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management in adults who meet the indication criteria. Each brand has its own FDA-approved labeling, packaging, and patient leaflet. 1 3

Whether you have been prescribed one or the other is a question for your clinician. Dosley supports tracking either brand and treats them as separate treatments.

Missed dose

If a Mounjaro injection is missed, the FDA label allows it to be taken as soon as possible within 4 days (96 hours) of the scheduled day. After that window, skip the missed amount and resume on the next regular day. 1

Questions

About this medication and Dosley

How often is Mounjaro injected?

Mounjaro is a once-weekly subcutaneous injection. Your prescriber sets the day of the week and the amount; Dosley records what they have set so you can see your history. 1

What if I forget my Mounjaro on the scheduled day?

The FDA-approved label states a missed dose may be taken within 4 days (96 hours) of the scheduled day. Past that window, the label says to skip it and resume on the next regularly scheduled day. If you are unsure, contact your clinician. 1

What are the most common Mounjaro side effects?

In the FDA label's adverse-reaction tables, the most common side effects at the 15 mg dose were nausea (about 18%), diarrhea (about 17%), decreased appetite (about 11%), vomiting (about 9%), and constipation (about 7%). 1

Is Mounjaro the same molecule as Zepbound?

Yes. Both Mounjaro and Zepbound contain tirzepatide, but each has its own FDA approval and indication: Mounjaro is approved for type 2 diabetes and Zepbound is approved for chronic weight management. Speak to your clinician about which is appropriate for your situation. 3

Where is Mounjaro injected?

The label specifies subcutaneous injection in the abdomen, thigh, or upper arm, with site rotation. Dosley lets you tag the site for each entry so you can see at a glance where you have already injected. 1

How should Mounjaro be stored?

The FDA label says Mounjaro should be kept refrigerated between 2°C and 8°C until first use. The in-use room-temperature window depends on the pen format you have been dispensed - check the leaflet that came with your pen. 1

On Dosley

How Dosley supports a Mounjaro routine

The home screen shows the next scheduled day, so you stop counting weeks off the calendar. Logging takes about five seconds - the day, the amount you were prescribed, the site. Most weeks that is the whole interaction.

Side-effect notes live next to each entry: pick from a list or type your own, and rate the severity. At your next appointment the log shows which weeks the symptoms clustered in, instead of asking you to remember.

Weight is tracked in the same place. Manual entry is two taps; a chart shows the trend rather than the daily noise, so a single bad-scale day does not break your week. If you use Apple Health, weight syncs automatically.

Pen tracking here is really refill tracking. Dosley records which pen you opened and when, so you can see what is left in the box before the week you need to collect more. Storage windows are reminders, not rules - follow the leaflet that came with your medication.

Guest Mode keeps entries on the device, so you can track without an account. Sign in and entries sync to your Dosley account, so a new phone does not start you over. Dosley does not automatically send your log to a clinic or anyone else, and there is no clinic dashboard or advertising. You control sharing: the free JSON export can be shared, and Premium adds a formatted PDF.

Dosley guides

Educational guides for Mounjaro tracking

What to track during a GLP-1 routine

Which details to write down during a GLP-1 routine, from injection dates and body region to pen supply, symptoms, and questions for your next appointment.

Track your treatment with Dosley

Log an injection with the day, dose, and site. Track weight and side effects separately.

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References

  1. 1. FDA-approved Mounjaro (tirzepatide) prescribing information (DailyMed)
  2. 2. Mounjaro USPI (Eli Lilly and Company)
  3. 3. Drugs@FDA: Mounjaro (NDA 215866)

Last reviewed:

Mounjaro is a registered trademark of Eli Lilly and Company. Dosley is not affiliated with, endorsed by, or sponsored by Eli Lilly and Company.