Mounjaro comes in six dose strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Everyone starts at the lowest dose and works up gradually, with the maximum approved dose capped at 15 mg per week. The step-by-step increase follows a specific schedule designed to give your body time to adjust.
The Six Available Doses
Each dose comes as a pre-filled pen containing 0.6 mL of solution, and you inject it once a week under the skin. The full lineup:
- 2.5 mg (starting dose)
- 5 mg
- 7.5 mg
- 10 mg
- 12.5 mg
- 15 mg (maximum dose)
Not everyone ends up on the highest dose. Your prescriber will work with you to find the strength that gives you adequate results with tolerable side effects, and that becomes your maintenance dose.
How the Dose Increases Work
You start at 2.5 mg once weekly for four weeks. This initial dose isn’t really a treatment dose. It’s there to let your body get used to the medication and reduce the intensity of side effects when you move up.
After those first four weeks, you increase to 5 mg. From there, each further increase goes up by 2.5 mg and requires at least four weeks on the current dose before stepping up. So if you were titrating all the way to the maximum, the timeline would look roughly like this:
- Weeks 1 through 4: 2.5 mg
- Weeks 5 through 8: 5 mg
- Weeks 9 through 12: 7.5 mg
- Weeks 13 through 16: 10 mg
- Weeks 17 through 20: 12.5 mg
- Week 21 onward: 15 mg
That’s about five months to reach the top dose. In practice, many people stay longer at certain steps, and some never go beyond 10 mg because it’s working well enough. The 2.5 mg increments at four-week intervals were specifically chosen during clinical development to improve tolerability.
What Higher Doses Deliver
Higher doses generally produce more weight loss and better blood sugar control, but the gains aren’t unlimited. In the SURMOUNT-2 trial, which studied people with obesity and type 2 diabetes, participants on 10 mg lost an average of 12.9 kg (about 28 pounds), while those on 15 mg lost 14.8 kg (about 33 pounds), compared to just 3.2 kg in the placebo group. About 79% of those on 10 mg and 83% on 15 mg achieved at least 5% body weight reduction. At the more ambitious threshold of 15% weight loss, 40% of the 10 mg group and 48% of the 15 mg group reached it.
For blood sugar, higher doses also brought greater reductions in HbA1c, the marker that reflects average blood sugar over the previous two to three months. The pattern is consistent: more medication generally means more effect, but the jump between 10 mg and 15 mg is smaller than the jump from lower doses, so the benefit of pushing to the maximum varies from person to person.
Side Effects During Dose Increases
Digestive side effects are the most common issue, and they tend to flare at two predictable moments: when you first start the medication and each time you step up to a higher dose. Nausea, diarrhea, constipation, and heartburn are the usual culprits. For most people, these symptoms settle within about a month at each new dose level, then may briefly return when you increase again.
If a particular dose is hard to tolerate, your prescriber may keep you at the lower dose for longer than four weeks to give your body more time to adjust. Some people find that they can manage side effects with dietary changes alone. Eating smaller meals throughout the day, avoiding greasy or high-fat foods, stopping when you feel full, and eating slowly all help with nausea. For diarrhea, leaner proteins, blander foods like rice and broth, and cutting back on caffeine and alcohol can make a difference. Constipation responds well to increasing water intake (aiming for roughly 91 to 125 ounces daily), daily exercise, and adding more fiber through fruits, vegetables, and whole grains.
Heartburn can be managed by avoiding spicy and fried foods, staying upright for at least two hours after eating, and sleeping with your head slightly elevated. If side effects persist despite these adjustments, a dose reduction is a reasonable option.
If You Miss a Dose
Take the missed dose as soon as you remember, as long as it’s within four days (96 hours) of when you were supposed to take it. If more than four days have passed, skip it entirely and take your next dose on the regular scheduled day. The key rule: never take two doses within three days of each other.
Where and How to Inject
Mounjaro is injected under the skin in one of three areas: the abdomen (at least two inches away from the belly button), the front of the thigh (avoiding the inner thigh), or the back of the upper arm. The upper arm typically requires someone else to administer the injection since it’s hard to reach on your own. Rotate between these sites each week to avoid irritation, bruising, or swelling at any single spot. Keeping a simple log of where you injected each time helps you stay on rotation.
Storing Your Pens
Unused pens belong in the refrigerator, stored between 2°C and 8°C (about 36°F to 46°F), protected from light, and never frozen. Once you start using a pen, it can stay at room temperature (up to 30°C or 86°F) for up to 30 days. After 30 days from first use, discard the pen even if medication remains inside.