Switching From Ozempic to Mounjaro: Doses and Conversion Chart

You can switch from Ozempic to Mounjaro, or from any semaglutide product to any tirzepatide product, but there is no FDA-approved conversion chart and no dose of one that is officially "equal" to a dose of the other. Mounjaro's label gives a single instruction for everyone: start at 2.5 mg once a week and increase in 2.5 mg steps no sooner than every four weeks. In practice, prescribers take one of two routes. Some restart every patient at 2.5 mg. Others, for people already tolerating a full semaglutide dose, begin at 5 mg. The first Mounjaro injection is normally given seven days after the last Ozempic injection, in place of it.

This guide explains what the labels say, what the published guidance suggests, how the same logic applies to Wegovy and Zepbound, and what to settle with your prescriber before changing. Do not switch on your own or use leftover pens from someone else; the starting dose is a medical decision.

Why there is no official Ozempic to Mounjaro conversion chart

Semaglutide and tirzepatide are different molecules. Semaglutide acts on the GLP-1 receptor. Tirzepatide acts on GLP-1 and GIP receptors. Their milligram scales are unrelated: Ozempic runs from 0.25 mg to 2 mg, Mounjaro from 2.5 mg to 15 mg, and neither number tells you anything about the other.

The trials that compared them (SURPASS-2 in type 2 diabetes, SURMOUNT-5 in obesity) started every participant from scratch on the assigned drug. They did not test moving people from one to the other. As a result, neither manufacturer's label contains a conversion table, and anything presented online as an "Ozempic to Mounjaro conversion chart" is someone's estimate.

What the labels do say:

• Mounjaro and Zepbound: the recommended starting dose is 2.5 mg weekly for four weeks, described as a dose for initiation rather than treatment. Increase to 5 mg, then by 2.5 mg at intervals of at least four weeks. There is no separate rule for people coming from another drug.
• Zepbound, Wegovy and Foundayo: do not use together with another GLP-1 receptor agonist. A switch means stopping one and starting the other, never overlapping.

A published comparison chart, and its limits

The closest thing to a reference is a 2023 special report in the American Diabetes Association journal Clinical Diabetes, written by pharmacists to help clinicians manage shortages. It offers "suggested comparative doses" for treating type 2 diabetes, based on how much each dose lowers blood sugar in separate trials. For semaglutide and tirzepatide it lines up as follows.

Weekly semaglutide (Ozempic)	Suggested comparable weekly tirzepatide (Mounjaro)	Note from the report
0.25 mg	None listed	Starter dose
0.5 mg	2.5 mg	Tirzepatide 2.5 mg is a starter dose; its placement reflects the authors' clinical judgment
1 mg	None listed (falls between 2.5 and 5 mg)
2 mg	5 mg	Based on indirect comparison of trials
No equivalent	7.5, 10, 12.5, 15 mg	Glucose lowering beyond any Ozempic dose

Read it with three cautions the authors themselves give or imply. First, it is about blood sugar in type 2 diabetes, not weight loss, and it predates Wegovy's 7.2 mg dose. Second, they describe an equivalent-dose chart as "a starting guide" and tell clinicians to weigh current glucose control, how long the patient has been off the medication, and how the first drug was tolerated. Third, tolerating one drug does not guarantee tolerating the other; tirzepatide's second mechanism is new to your body.

One conclusion is safe to draw: nobody goes straight from Ozempic to Mounjaro 10 mg or 15 mg. Even the most generous reading of the chart tops out at 5 mg for a first tirzepatide dose.

How prescribers usually handle the switch

Approach	What happens	Often chosen when
Restart low	Begin tirzepatide 2.5 mg for four weeks, then 5 mg, then step up as needed	You were on a low semaglutide dose, had stomach side effects, have had a gap in treatment, or your prescriber follows the label strictly
Start at 5 mg	Begin tirzepatide 5 mg, review at four weeks, then step up as needed	You have been stable on Ozempic 1 mg or 2 mg (or Wegovy 1.7 or 2.4 mg) with no significant side effects and no missed doses

The first approach costs a few weeks at a dose that may control blood sugar or appetite less than what you were on. The second avoids that dip but carries a somewhat higher chance of nausea. Either way, the climb above 5 mg follows the label: 2.5 mg at a time, at least four weeks on each step, to a maximum of 15 mg.

Timing

The published guidance is simple for two weekly drugs: begin the new product seven days after the last dose of the old one. In other words, on the day your next Ozempic shot would be due, take Mounjaro instead. No washout period is needed, and you should not wait longer hoping to "clear" the first drug; a long gap just means lost control and a rougher restart.

Semaglutide lingers. Its half-life is about one week, and Ozempic's label notes it remains in circulation for about five weeks after the last dose. For the first month on tirzepatide you have some of both in your system, which is one reason prescribers start low.

A typical timeline

Here is an illustration for an adult with type 2 diabetes moving from Ozempic 1 mg, using the more cautious approach. Your own plan may differ.

1. Week 0: last Ozempic 1 mg injection on your usual day.
2. Week 1: first Mounjaro injection, 2.5 mg, same day of the week. Continue for four weekly doses. Check blood sugar as advised; readings may run a little higher for a few weeks.
3. Week 5: increase to 5 mg. Stay at least four weeks.
4. Week 9 onward: if A1C or weight goals are not met and you are tolerating the drug, increase to 7.5 mg, and later to 10, 12.5 or 15 mg, each for at least four weeks. Many people stay at 5 or 10 mg.
5. About three months in: recheck A1C and review weight, side effects and cost with your prescriber.

What to expect after switching

Results

No randomized trial has measured outcomes after a semaglutide-to-tirzepatide switch. A modeling study published in 2024 by Eli Lilly researchers used trial data to simulate it: people on semaglutide 0.5 to 2 mg were predicted to have A1C reductions of about 1.2 to 1.8 points and weight loss of 3.6 to 6.9 kg at 26 weeks, improving to about 2.0 to 2.5 points and 6.5 to 12.1 kg by week 66 after switching to tirzepatide 5, 10 or 15 mg. It is a simulation from the manufacturer, so treat it as a plausible direction, not a promise. The head-to-head trials do support the general expectation: at full doses, tirzepatide lowered A1C and weight more than semaglutide on average.

Side effects

Expect the familiar ones to flare for a while: nausea, diarrhea, constipation, reduced appetite, sometimes vomiting, mostly in the first weeks and after each increase. Practical measures clinicians recommend include smaller meals, eating slowly, stopping when full, limiting high-fat and very sweet foods, and drinking enough fluid. If a dose is hard to tolerate, staying on it longer before the next increase, or stepping back down, is a standard adjustment.

Call your prescriber for vomiting or diarrhea that lasts more than a day or two, signs of dehydration such as dizziness or very dark urine, or any change in vision. Get emergency care for severe abdominal pain that does not go away, with or without vomiting, or for swelling of the face, lips or throat or trouble breathing.

Things that are different with tirzepatide

• Birth control pills. Mounjaro and Zepbound labels advise switching to a non-oral contraceptive or adding a barrier method for four weeks after starting and for four weeks after each dose increase. This did not apply on injectable semaglutide, so it is easy to overlook.
• The device. Ozempic is a multi-dose dial pen. Mounjaro usually comes as four single-dose auto-injectors. Ask for a demonstration.
• Missed-dose window. Four days for tirzepatide, compared with five for Ozempic.
• Insulin and sulfonylureas. If you take either, your prescriber may lower the dose when you switch, because better glucose control raises the risk of low blood sugar.

Switching from Wegovy to Zepbound

The weight-management pair works the same way, because Zepbound has the same tirzepatide doses as Mounjaro. Zepbound's label starts everyone at 2.5 mg for four weeks. There is no official Wegovy-to-Zepbound dosage chart.

You are taking	Common first Zepbound dose	Then
Wegovy 0.25 or 0.5 mg	2.5 mg	5 mg after four weeks
Wegovy 1 mg	2.5 mg	5 mg after four weeks
Wegovy 1.7 or 2.4 mg, well tolerated	2.5 mg or 5 mg, at the prescriber's discretion	Increase by 2.5 mg at least four weeks apart toward 10 or 15 mg if needed
Wegovy HD 7.2 mg	Individual decision; no published guidance yet

This table describes common practice, not a labeled or validated conversion. People who switch from a full Wegovy dose to Zepbound 2.5 mg sometimes notice appetite returning for a few weeks until the dose rises. That is expected and temporary; it is not a sign the new drug is failing. More on how the two compare is in Wegovy vs Zepbound.

Switching the other way: tirzepatide to semaglutide

People move from Mounjaro to Ozempic or from Zepbound to Wegovy mostly because of insurance changes, cost or supply. The same principles apply in reverse, with some differences.

• Labeled starting doses. Ozempic and Wegovy both start at 0.25 mg for four weeks. Some prescribers start a person coming from tirzepatide at a higher step, such as 0.5 mg or 1 mg, to avoid a long period of under-treatment. That is a judgment call, not a label instruction.
• Expect a possible step down in effect. On average, semaglutide at standard doses lowers weight and A1C less than tirzepatide at 10 or 15 mg. Some people hold steady; others see appetite, weight or glucose drift up. Wegovy's 7.2 mg dose is an option for adults who have tolerated 2.4 mg for at least four weeks and need more weight reduction.
• Timing. First semaglutide dose seven days after the last tirzepatide dose.
• Kidney or heart reasons. If the move is to gain Ozempic's kidney indication or Wegovy's cardiovascular indication, the target dose matters: 1 mg for Ozempic in chronic kidney disease, 2.4 mg for Wegovy.

Same-ingredient switches are simpler

Switch	What the label or standard practice says
Mounjaro to Zepbound, or back	Same drug and strengths. Usually continue the same dose on the same day with a new prescription. See Mounjaro vs Zepbound.
Ozempic to Wegovy, or back	Same drug. No labeled conversion; prescribers commonly continue at the matching or nearest dose step. See Ozempic vs Wegovy.
Wegovy injection to Wegovy tablets	Labeled: a person on 2.4 mg weekly may start 25 mg tablets once daily, one week after the last injection.
Wegovy tablets to Wegovy injection	Labeled: start 2.4 mg weekly the day after the last 25 mg tablet; consider 1.7 mg if the tablets were poorly tolerated.
Ozempic injection to Ozempic tablets or Rybelsus	Labeled: a person on 0.5 mg weekly may start Ozempic tablets 4 mg or 9 mg (or Rybelsus 7 mg or 14 mg) one week after the last injection.
Rybelsus to Ozempic tablets	Labeled: after the first 30 days, 7 mg corresponds to 4 mg and 14 mg to 9 mg; start the day after the last dose of the other tablet.

The pill options, including Lilly's Foundayo, are compared in Foundayo vs the Wegovy pill.

Should you switch from semaglutide to tirzepatide?

Reasons that commonly justify a conversation:

• You have been on the highest dose you can tolerate for at least three months and your A1C or weight is still above the goal you and your prescriber set.
• Side effects on semaglutide have not settled despite slower dose increases.
• Your insurance changed its preferred drug.
• You have moderate to severe obstructive sleep apnea with obesity, which Zepbound is approved to treat.

Reasons to pause before switching:

• You are doing well. A drug that is working and tolerated is hard to improve on, and every switch means a new escalation period.
• You have type 2 diabetes with chronic kidney disease. Ozempic is the drug with a kidney indication.
• You have cardiovascular disease without diabetes. Wegovy has outcome evidence in that group; Zepbound does not.
• You have not yet tried the higher semaglutide dose available to you: Ozempic 2 mg, or Wegovy 7.2 mg for weight.
• The cash price is higher. As of October 14, 2026, Mounjaro pens are $499 a month through LillyDirect and Zepbound is $299 to $449 with on-time refills, versus $349 for most Ozempic and Wegovy doses. See GLP-1 cost without insurance.

Checklist before you switch

1. Confirm the new drug and brand match your diagnosis: Mounjaro for type 2 diabetes, Zepbound for weight management or sleep apnea.
2. Ask whether prior authorization is needed and how long it takes. Do not stop the old drug until the new one is approved and in hand.
3. Agree on the starting dose and the date of the first injection (seven days after your last one).
4. Ask for training on the new pen, vial or KwikPen.
5. Review other medicines: birth control pills, insulin, sulfonylureas, and anything that needs steady absorption, such as warfarin.
6. Know who to call about side effects and what would prompt a dose reduction.
7. Check which savings card or self-pay program applies; the old brand's card will not work.
8. Store or dispose of leftover pens properly. Do not give them to anyone else.
9. Schedule a follow-up at four to twelve weeks.

Mistakes to avoid

• Taking both drugs in the same week. This raises the risk of severe nausea, vomiting and dehydration.
• Matching milligrams. Ozempic 2 mg does not equal Mounjaro 2.5 mg, and jumping to a high tirzepatide dose because you were on a "high" semaglutide dose is unsafe.
• Splitting or combining pens to make an in-between dose. The manufacturers advise against it.
• Restarting at your old dose after a gap. After several missed weeks, both the Wegovy label and published guidance favor restarting lower.
• Buying from an unverified online seller to bridge a gap. Counterfeit pens have been reported, and compounded products are not FDA-approved. The same goes for non-prescription "GLP-1" products such as patches, which contain neither drug.

For the evidence behind the two drugs, see Ozempic vs Mounjaro and semaglutide vs tirzepatide.