Mounjaro is tirzepatide, injected weekly under the skin, and it is licensed in the United States for type 2 diabetes only. The identical molecule is sold as Zepbound for weight management. Same drug, same ladder, different label — and prescribing Mounjaro for weight is off-label use of a product whose sibling holds exactly that license.
Because the indication is diabetes, the question at each checkpoint is not how much weight has come off. It is what your blood sugar is doing.
The ladder
| Dose | Minimum time before moving on | What it is |
|---|---|---|
| 2.5 mg | 4 weeks | A run-up. It is not treating your diabetes; it is letting your stomach get used to the drug. |
| 5 mg | 4 weeks | The first dose doing real work. A good number of people never need to go past it. |
| 7.5 mg | 4 weeks | Only worth reaching for if your numbers are still above target. |
| 10 mg | 4 weeks | Where patients aged 10 to 17 stop. Younger patients stop here. |
| 12.5 mg | 4 weeks | Again, only if glycemic control is still short. |
| 15 mg | — | The adult ceiling. Nothing above it is authorized. |
Increases go up in 2.5 mg steps and never sooner than four weeks apart.
Climb, hold, or come down
At each four-week checkpoint the decision has more than two options, and “hold” is the one people forget exists.
| Where you are | What that argues for |
|---|---|
| Blood sugar still above target, side effects manageable | Move up a step. |
| Target met, fasting glucose where it should be, feeling fine | Stay. Climbing further buys you nothing and costs you tolerability. |
| Nausea, vomiting or diarrhea that is interfering with your day | Hold this dose another four weeks. Do not advance into it. |
| Severe symptoms, dehydration, or bad abdominal pain | Drop a level or stop, and speak to your prescriber. |
| Hypoglycemia keeps happening on insulin or a sulfonylurea | Do not step up. Bring the other drug down first, then look again. |
The usual A1C target is below 7%, but that figure is a default rather than a law — a younger person at low risk of hypos may be aimed lower, and an older person with other things going on may sensibly be aimed higher. Ask what yours is.
Practical points
- Same day weekly, any hour, food irrelevant. Abdomen, thigh or upper arm, moving the site each week and staying off bruised or tender skin.
- Four weeks is a floor, not a schedule. Eight or twelve weeks at a dose is perfectly reasonable if your numbers are acceptable or your gut still objects.
- Storage catches people out: unused pens live in the fridge, and once out they last 21 days at room temperature — noticeably shorter than Ozempic's 56 or Wegovy's 28. Do not assume the pens behave alike.
- Prior authorization for Mounjaro usually turns on a documented A1C and a previous metformin trial. Requests framed around weight alone are commonly refused, because weight is Zepbound's license and not this one's.
A missed dose
- Within four days (96 hours): get it in when you are able, then return to your normal weekly day.
- Beyond four days: skip it, and take the next one when it was already due.
- Moving your injection day is fine so long as 72 hours separate the two doses.
- Two or more missed in a row is something to put to your prescriber rather than decide alone — going back a step may be safer than resuming where you left off.
Never take two doses to catch up.
Reasons to stop and call
- Severe abdominal pain that persists, especially boring through to the back. Pancreatitis. Stop the drug and get seen.
- Right-sided pain under the ribs, fever, yellowing, pale stools. Gallstones showed up more often on tirzepatide than on placebo.
- Severe hypoglycemia — confusion, collapse, a seizure — where insulin or a sulfonylurea is also in play. The label warns about this combination specifically, and the usual fix is reducing the other drug.
- A day of not keeping fluids down, dizziness standing up, dark or scanty urine. Kidney injury follows dehydration.
- A neck lump, a hoarse voice, trouble swallowing. The boxed warning covers thyroid C-cell tumors; medullary thyroid carcinoma in your family or MEN 2 rules the drug out completely.
- Sight changing, since blood sugar improving fast can briefly worsen diabetic retinopathy.
- Hives, a swollen face or throat, breathing difficulty. Emergency care.
Outside this page's scope
This is the dosing skeleton for type 2 diabetes and nothing else. Ketoacidosis (which can present oddly on incretin therapy), the full workup for suspected pancreatitis, pregnancy, fasting before surgery, the multidose KwikPen instructions, and use after bariatric surgery all need more than a reference card. So does Mounjaro for weight loss, which belongs under Zepbound's license rather than this one.
Where to go next
- The Mounjaro page — how it works, the SURPASS results, pricing.
- Titration planner — your ladder week by week.
- Missed-dose guide — the windows differ by drug, and this works through each.
- Ozempic against Mounjaro — the head-to-head for type 2 diabetes.