How Long Does Mounjaro Stay in Your System?

The half-life of Mounjaro is approximately 5 days.

This is the time it takes your body to remove 50% of the medicine from your bloodstream.

Because of this long half-life, Mounjaro only needs to be taken once weekly, and its effects build and fade gradually rather than suddenly.

Further reading: Mounjaro doses

• Most of the medicine is cleared within 25-30 days
• Only trace amounts remain after about 4 weeks
• Near-complete elimination occurs by 5-6 weeks

Even once blood levels are very low, some people may still notice side effects and reduced appetite for a short period.

How long Mounjaro remains in your body can vary slightly from person to person. Factors that can influence clearance include:

Your metabolism

People with a faster metabolism may clear the drug a little quicker, while a slower metabolism can extend how long it stays in the body.

Liver and kidney function

These organs help remove medicines from the bloodstream. Reduced liver or kidney function can slow elimination.

Age and body weight

Older adults and people with a lower body weight may take slightly longer to clear Mounjaro. Higher body weight can sometimes shorten clearance time.

Dose and duration of treatment

Higher doses or long-term use can lead to more drug accumulation, which may take longer to fully clear.

Other medicines or health conditions

Some medications or medical conditions can affect how quickly your body processes drugs in general.

After a Mounjaro injection, blood levels rise gradually and typically peak about 24–72 hours later, with most people reaching peak concentration at around 48 hours.

This slow rise is part of why it can be taken once weekly and why side effects such as nausea often feel worse a day or two after the injection rather than immediately.

Whether due to side effects, medical procedures, or personal health choices, some people may need to discontinue Mounjaro sooner than planned.

Here’s how to support your body during the process:

Certain situations require extra care when thinking about how long Mounjaro stays in your system.

Stopping Mounjaro

If you stop suddenly, the medicine will leave your body gradually based on its half-life. Appetite suppression may fade before the drug is fully cleared. How your body responds depends on how long you were taking it and at what dose.

Further reading: Stopping Mounjaro

Pregnancy and breastfeeding

Mounjaro is not recommended during pregnancy or breastfeeding. Because it remains in your system for several weeks, discuss timing with your healthcare provider before trying to conceive or resuming breastfeeding.

Planning surgery or medical procedures

Mounjaro can affect blood sugar and digestion. Your clinician may advise stopping it temporarily before surgery. Clearance time varies between individuals.

Other medications

Some medicines can interact with Mounjaro or affect how quickly it is cleared. Always review prescriptions, supplements, and over-the-counter medicines with your prescriber.

Health conditions

Kidney, liver, or gastrointestinal conditions can alter how long Mounjaro stays in your system and may affect how and when the medication should be stopped or adjusted.

Mounjaro has a half-life of about five days. A half-life is the time it takes for the amount of medicine in your body to reduce by half.

After each five-day period, the level halves again (50% → 25% → 12.5% → 6.25% → and so on). After around five to six half-lives, roughly 25-30 days, most of the drug has been cleared, with near-complete elimination taking about 5-6 weeks.

During this time, effects such as appetite suppression and mild side effects gradually fade. If you plan to stop treatment, have surgery, or are considering pregnancy, speak with your clinician for personalised advice on timing.