Mounjaro vs Ozempic for Type 2 Diabetes — Labels and SURPASS-2

You have had type 2 diabetes for a few years, metformin is no longer quite enough, and your doctor has put two names on the table. A neighbor swears by Ozempic; a cousin just started Mounjaro. You would like to understand what actually differs before your next appointment — not to pick for yourself, but to ask better questions.

What is each one approved for?

Both are weekly injections used alongside diet and exercise to improve blood sugar in type 2 diabetes. After that, the labels diverge.

Ozempic's label lists two further uses in adults with type 2 diabetes: lowering the risk of major heart events in people with established heart disease, and lowering the risk of kidney decline, kidney failure and heart-related death in people with chronic kidney disease. Mounjaro's label lists blood sugar control only, but for children 10 and older as well as adults.

If heart or kidney disease is part of your history, that difference is worth raising directly with your prescriber.

How do they work differently?

Ozempic is semaglutide, which acts on the GLP-1 receptor. Mounjaro is tirzepatide, which acts on both the GIP and GLP-1 receptors. Both slow how quickly the stomach empties, which is one reason their labels warn that the absorption of other tablets may be affected.

What did SURPASS-2 show?

SURPASS-2 is the head-to-head trial most people mean when they compare these two. It enrolled 1,879 adults with type 2 diabetes already on metformin, and randomized them to Mounjaro 5, 10 or 15 mg or Ozempic 1 mg for 40 weeks. It was open-label and funded by Lilly.

Result at 40 weeks	Ozempic 1 mg	Mounjaro 5 mg	Mounjaro 10 mg	Mounjaro 15 mg
Average HbA1c change	−1.86	−2.01	−2.24	−2.30
Weight difference vs Ozempic	—	−1.9 kg	−3.6 kg	−5.5 kg

Two things to keep in mind. These are averages, and individual responses varied widely. And the trial used Ozempic's 1 mg dose; the label now allows up to 2 mg, which SURPASS-2 did not test.

How do the dose schedules compare?

Both start low and climb in 4-week steps to limit stomach side effects.

• Mounjaro: 2.5 mg for 4 weeks, then 5 mg; further 2.5 mg steps if more glucose control is needed, at least 4 weeks apart, up to 15 mg in adults.
• Ozempic: 0.25 mg for 4 weeks, then 0.5 mg; then 1 mg and 2 mg if more glucose control is needed, each after at least 4 weeks on the previous dose.

Mounjaro's label says its 2.5 mg starting dose is for beginning treatment, not for glucose control. Ozempic's lists 0.5 mg as its lowest maintenance dose, with 1 mg as the maintenance dose for people with chronic kidney disease. Your prescriber decides when, and whether, to step up.

Are the pens and routines different?

A little. Ozempic comes in multi-dose pens and, on the current label, single-dose prefilled syringes. Mounjaro comes in single-dose pens and vials, multi-dose vials and a four-dose KwikPen.

Both labels list the abdomen, thigh and upper arm, though Mounjaro's says the back of the upper arm should be injected by someone else. Ozempic allows a missed dose within 5 days; Mounjaro within 4. Moving your shot day needs at least 2 days between doses on Ozempic and at least 3 on Mounjaro.

How do side effects compare?

In SURPASS-2, nausea affected 17% to 22% on Mounjaro and 18% on Ozempic; diarrhea 13% to 16% and 12%; vomiting 6% to 10% and 8%. Most cases were mild to moderate. Both labels share similar warnings, including pancreatitis, gallbladder problems, low blood sugar with insulin or sulfonylureas, diabetic retinopathy complications and a boxed warning about thyroid tumors seen in rodents.

What we'd track

On either medicine, these are the notes we would keep for diabetes appointments.

1. Every shot, dose and time. The missed-dose window depends on which medicine you use.
2. Side effects against dose steps. To see whether stomach symptoms settle after each increase.
3. Low glucose episodes. Especially if you also take insulin or a sulfonylurea.
4. Meals and protein. Appetite can drop on both; a photo log keeps it honest.
5. Weight trend. Useful context for your diabetes team, without daily fuss.

Holt logs shots, sites, side effects, meals and weight on your iPhone, syncs with Apple Health and builds a doctor-visit report. It is free to download, with an optional subscription.

Bring a clearer log to your next diabetes visit