The tirzepatide titration schedule

Tirzepatide is sold as Mounjaro for type 2 diabetes and Zepbound for weight and obstructive sleep apnoea. It is the same molecule, and the dose ladder is the same on both labels. The reason for the ladder is the gut. Starting at a full dose causes far more nausea, vomiting and diarrhoea, and climbing in steps lets the body adapt. The labels say so directly: the escalation is there "to reduce the risk of gastrointestinal adverse reactions".

The ladder

In full, at the fastest pace the label allows:

The wording that matters is "after at least 4 weeks on the current dose". Four weeks is the minimum, not the schedule. Prescribers often hold longer at a step if side effects are still settling or the current dose is working. The Zepbound label adds: "If patients do not tolerate a maintenance dosage, consider a lower maintenance dosage." The titration glossary entry explains the general idea, and the side effects by week page explains why four weeks.

Maintenance doses by label

• Zepbound, weight reduction and long-term maintenance: 5, 10 or 15 mg once weekly.
• Zepbound, obstructive sleep apnoea: 10 or 15 mg once weekly.
• Mounjaro, type 2 diabetes in adults: step up "if additional glycemic control is needed", to a maximum of 15 mg.
• Mounjaro, type 2 diabetes in children 10 and older: maximum 10 mg.

The odd-numbered steps, 7.5 and 12.5 mg, are rungs on the ladder. On the Zepbound label they are not listed as maintenance doses for weight. The prescriber sets the dose.

What each maintenance dose did in SURMOUNT-1

SURMOUNT-1 randomised 2,539 adults without diabetes to 5, 10 or 15 mg or placebo for 72 weeks, including a 20-week climb that followed exactly this ladder. The Zepbound label reports the results:

And the common side effects, pooled from SURMOUNT-1 and SURMOUNT-2 on the label:

Two things stand out. The step from 5 to 10 mg added 4.5 points of weight loss on average; the step from 10 to 15 mg added 1.4. And the label notes that most people who stopped for side effects did so in the first few months, during the climb. The SURMOUNT page has the full trial results.

Formats: pens, vials and the KwikPen

Both labels list four presentations, each in all six strengths, 2.5 to 15 mg:

• Single-dose pen. One autoinjector per weekly dose, 0.5 mL.
• Single-dose vial. One vial per weekly dose, 0.5 mL, drawn up with a syringe.
• Multi-dose vial. Four doses per vial, 0.6 mL each, 2.4 mL in total.
• KwikPen. A single-patient-use pen holding four doses, 2.4 mL in total. The label says never to share a KwikPen between people, even with a new needle, and that it is not recommended for self-injection by people with impaired vision.

For vials, the labels say to use a syringe that can measure a 0.5 or 0.6 mL dose, such as a 1 mL syringe, and a new syringe and needle for every injection. Because each strength is a separate product, moving up a step means a new prescription for the new strength.

Storage, from the labels: refrigerate at 2 to 8°C. A single-dose pen or vial can be kept unrefrigerated, up to 30°C, for a total of 21 days. An opened multi-dose vial or KwikPen must be thrown away after 30 days at room temperature, 30 days after first use, or after four weekly doses, whichever comes first, even if medicine is left. The storage page covers the general rules. Compounded tirzepatide follows the pharmacy's own instructions, not the label; see tirzepatide reconstitution.

Missed doses and changing your day

The rule is the same on both labels:

• If you miss a dose, take it as soon as possible within 4 days (96 hours).
• If more than 4 days have passed, skip it and take the next dose on your usual day.
• You can change your injection day, as long as the two doses are at least 3 days (72 hours) apart.

Missing more than one dose is a different situation: tirzepatide's half-life is about five days, so after two or three missed weeks the drug level is much lower and restarting at the old dose can bring back the side effects of the first weeks. That is a question for the prescriber, who may restart lower. The missed dose page has more.

Other label points that bear on the climb

• Oral contraceptives. Tirzepatide slows the stomach and may reduce absorption of the pill. The Zepbound label advises switching to a non-oral method, or adding a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase.
• Do not combine. The labels advise against taking tirzepatide with any other tirzepatide product or any GLP-1 receptor agonist.
• Injection. Once weekly, any time of day, with or without food, into the abdomen or thigh, or the back of the upper arm if someone else injects. Rotate sites each week.

Comparing ladders

Semaglutide climbs over 16 weeks to 2.4 mg on Wegovy; tirzepatide over 20 weeks to 15 mg on Zepbound at the fastest pace. The brand comparison sets the ladders side by side, and the maintenance dose page covers choosing where to stop. For trial context, see the master table and semaglutide vs tirzepatide.

The ladder is easiest to follow written down: the date of each step, the dose, how the first week felt, and your weight at week four. Peptide AI builds the titration schedule from your prescription, reminds you of the weekly dose, counts doses left in a multi-dose vial or KwikPen, and puts side effects and weight on the same timeline, all on the free tier. See the Mounjaro tracker, the Zepbound tracker or the free GLP-1 tracker.