How long does semaglutide stay in your body?

The short answer: about a week for half of it to leave, and about five weeks for nearly all of it. Semaglutide, the medicine in Ozempic, Wegovy and Rybelsus, is built to last, which is why one shot covers seven days. Tirzepatide, in Mounjaro and Zepbound, is a little quicker at about five days. Knowing the shape of that curve explains most of what a week on these medications feels like, and it is the background to every question about a late shot, a missed one, or stopping.

A week for half, five weeks for all

The label puts it plainly: semaglutide has an elimination half-life of approximately one week, and it will be present in the circulation for about five weeks after the last dose.¹ A half-life is the time for half of what is in your blood to go. After one week, half is left; after two, a quarter; after five, about three percent, which is close enough to nothing that the label calls it gone.

The other end of the curve matters just as much. After a shot, the level climbs for one to three days before it peaks.¹ And because each weekly shot lands on top of what is left from the last, the level keeps building for the first month: steady state, the point where each new dose only replaces what was lost, arrives after four to five weeks of weekly injections.¹

Rybelsus, the tablet, is the same molecule and has the same half-life of about a week, reaches steady state after the same four to five weeks, and stays in the circulation for the same five weeks.³ The pill is taken daily because so little of each tablet is absorbed, not because it leaves faster.

Tirzepatide is different enough to say. Its half-life is about five days, it peaks anywhere from eight to seventy-two hours after the shot, and it reaches steady state after four weeks.⁴ Same shape, slightly shorter week.

What the curve feels like across a week

Lay the curve over your diary and the week explains itself. Day 1 the level is climbing. Day 2 it peaks, the stomach is at its slowest, and that is the queasy morning. Days 3 to 5 the level is high and steady, the appetite is quiet, eating is easy. Days 6 and 7 the level is at its lowest point of the week, about half of what it was at the peak, and for many people that is when the appetite creeps back and the thoughts about food get louder.

Two things soften that over time. Once you reach steady state, the day 7 low point is higher than it was in week one, because it sits on top of four weeks of doses. And once the dose has stepped up, every point of the curve is higher. The dip is still there; it is just less deep. People who log their weeks usually see the end-of-week feeling shrink over the first two or three months for exactly that reason.

A late shot

Life moves shot day sometimes. The labels allow it, with a floor on how close two doses may be. For Ozempic, the day of the weekly dose can be changed as long as there are at least two days, more than 48 hours, between the two doses.¹ Wegovy follows the same two-day rule.² For Mounjaro the gap has to be at least three days, 72 hours.⁴

What a late shot feels like is the curve stretched: the low point of the week comes and stays a little longer, so the loud day may become a loud day and a half. Nothing dangerous happens at day 8 or 9; you are still well inside the five weeks. But whether to move a dose, and to which day, is your prescriber’s call, and worth a message before you do it rather than after.

A missed shot

The rules differ by medication, and they are written on the label, not made up on the day.

• Ozempic: if a dose is missed, take it as soon as possible within five days of the missed dose. If more than five days have passed, skip it and take the next dose on the regular day.¹
• Wegovy: if the next scheduled dose is more than two days away, take the missed one as soon as possible. If the next dose is less than two days away, do not take the missed one; wait for the regular day.² If two or more doses in a row are missed, the label asks the prescriber to restart the dose step-up at a lower dose,² and the patient guide says to contact them.
• Mounjaro: take the missed dose within four days, 96 hours; after that, skip it and resume on the regular day.⁴
• Rybelsus: skip the missed tablet and take the next one the following day.³

Never take two doses to catch up. A missed week is not a disaster: at day 14 you still have about a quarter of the peak level from the last shot. What you will notice is the appetite coming back for a few days, and possibly a return of the day 2 nausea after the next shot, since the level climbs from lower.

Stopping, and what five weeks means

If you stop, nothing switches off on the day. The level halves each week, so the appetite returns gradually over a month or more, and most people describe the food noise coming back before the hunger does. The five weeks in the label are also why it asks anyone planning a pregnancy to stop at least two months beforehand, because of the long washout.¹ Whether and how to stop is a decision to make with your prescriber; the curve only tells you what to expect afterwards.

What to write down

Three things make every one of these conversations easier: the day and time of each shot, any shot that was late or missed, and how you felt on each day of the week. Three weeks of that and the curve stops being a diagram and becomes your own week, with its own quiet days and its own loud one.

Tilly keeps that journal for you, counts the days since the last shot, and shows where you are on the week. It never tells you what dose to take, when to take it, or whether to move it. That is the label’s job first and your prescriber’s always.