Mounjaro comes in six doses: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Each dose is a single-use prefilled pen injected once per week. Everyone starts at the lowest dose and works up gradually, a process called titration that helps your body adjust and reduces side effects.
All Six Available Doses
Every Mounjaro pen delivers its dose in 0.5 mL of liquid, regardless of the strength. The six options are:
- 2.5 mg (starting dose)
- 5 mg (first maintenance dose)
- 7.5 mg
- 10 mg
- 12.5 mg
- 15 mg (maximum dose)
The pens are also available as single-dose vials for those who prefer a syringe. The color of each pen differs by strength, making it easy to confirm you’re using the right one.
How the Dose Increases Over Time
You start at 2.5 mg once weekly for the first four weeks. This isn’t really a treatment dose. It’s designed to let your body get used to the medication and minimize nausea and other gut-related side effects. After four weeks, your prescriber bumps you up to 5 mg, which is the first dose considered therapeutic.
From there, increases happen in steps of 2.5 mg at a time, with a minimum of four weeks at each level before moving up. Not everyone needs to reach 15 mg. Your prescriber will assess how well your blood sugar is responding (and, if relevant, how much weight you’re losing) at each step. Some people get good results at 5 mg or 10 mg and stay there. Others need the full 15 mg to hit their goals. The schedule might look something like this: 2.5 mg for four weeks, then 5 mg for at least four weeks, then 7.5 mg, then 10 mg, and so on.
The intermediate doses of 7.5 mg and 12.5 mg exist specifically to make the climb more gradual. Jumping straight from 5 mg to 10 mg, for instance, would double the dose at once. The 7.5 mg step in between gives your digestive system time to catch up.
Why Side Effects Spike During Dose Changes
The most common side effects of Mounjaro are nausea, vomiting, and diarrhea, and they’re closely tied to dose increases. In clinical studies, most of these gastrointestinal events happened during the weeks right after a dose went up, then tapered off as the body adjusted. People taking Mounjaro experienced these side effects at higher rates than those on placebo, and GI symptoms were the main reason some participants stopped treatment.
If side effects are rough after a dose increase, your prescriber may keep you at your current dose for longer than four weeks before trying the next step up. Eating smaller meals, avoiding high-fat foods, and staying hydrated can also help during the adjustment period. The goal is to find the lowest effective dose, not to rush to the maximum.
What Mounjaro Is Approved For
Mounjaro (tirzepatide) is FDA-approved to improve blood sugar control in adults and children aged 10 and older with type 2 diabetes, alongside diet and exercise. It works by activating two gut hormone receptors, GIP and GLP-1, which stimulate insulin release when blood sugar is high, slow digestion, and reduce appetite. The same active ingredient is sold under the brand name Zepbound when prescribed specifically for weight management, though the doses are identical.
What to Do If You Miss a Dose
Mounjaro is taken once a week, on the same day each week. If you miss your scheduled day, take the injection as soon as you remember, as long as it’s within four days of the missed dose. If more than four days have passed, skip it entirely and take your next dose on the regularly scheduled day. Never take two doses in the same week to make up for a missed one.
How to Store the Pens
Unused pens should be kept in the refrigerator between 36°F and 46°F (2°C to 8°C). If you need to carry a pen with you or don’t have fridge access, an unused pen can sit at room temperature (up to 86°F or 30°C) for up to 30 days. After 30 days outside the fridge, throw it away even if it still contains medication. Never freeze a Mounjaro pen. If one accidentally freezes, discard it.