Stopping a GLP-1, and what the year after looks like

People stop for good reasons: cost, supply, pregnancy plans, side effects, reaching a goal, or a prescriber's call. The evidence on what follows is clearer than for almost any other question on these pages, and it is not comfortable. Knowing it in advance is the point.

What the trials found

Semaglutide. In the STEP 1 extension, people who had lost an average of 17 percent of body weight over 68 weeks on semaglutide regained about two thirds of it in the year after the trial ended. Blood pressure, lipids and HbA1c drifted back toward where they started.

Tirzepatide. In SURMOUNT-4, everyone took tirzepatide for 36 weeks and lost about 21 percent. Half were then switched to placebo for a year. That half regained roughly 14 percentage points of it. The half that stayed on lost a further 5 percent.

Neither trial had a structured plan for the people who stopped. They stopped, and the drug stopped. That is the gap you can do something about.

How long the drug takes to leave

Semaglutide's half-life is about a week, so it takes roughly five weeks to clear. Tirzepatide's is about five days, so a little under four weeks. Appetite usually returns on the same curve: not on day one, but noticeably by week two, and fully by the time the drug is gone. Our clearance page has the numbers for every drug.

Tapering, or not

The labels do not describe a taper, and the trials above stopped cold. Some prescribers step the dose down over a couple of months anyway, on the reasoning that a gradual return of appetite is easier to manage than a sudden one. There is not strong trial evidence either way yet. If your prescriber offers a taper, the log shows how each step down went, which is the only way to tell whether it is helping.

A plan for the months after

• Protein and resistance training, before you stop. The weight you want to keep off is fat. The weight you lost that you want back is muscle. Our muscle page covers what the trials show and what to do about it.
• Weigh weekly, not daily. A small regain in the first two months is expected as the gut refills and appetite returns. The number to watch is the three month trend.
• Keep the food log going. It is the one habit that most reliably survives the drug. Calories and protein, roughly, every day.
• Agree the restart rule in advance. Many people and prescribers agree a weight at which the drug goes back on. Deciding it while you are calm beats deciding it in month four.

Stopping for side effects

If you are stopping because of persistent vomiting, severe abdominal pain, or anything your prescriber flagged, the clearance timeline above is also the timeline for the side effect to fade. Most gut side effects ease within one to two weeks of the last dose, well before the drug has fully gone.

The log through a stop is the same log as before, with the dose line ending. In Peptide AI the weight, food and, on Premium, the wearable lines keep going, so the months after are as visible as the months on. Logging is free.