What to Do If You Miss a GLP-1 Dose

This should be a simple question and it is not, because the four common products give four different answers — and two of them contain the same molecule.

The windows

Confirm these against the prescribing information for the product in your hand, because formulations and labels change and yours is the one that governs.

Ozempic and Wegovy are the same molecule with very different missed-dose windows — 5 days against 48 hours. That is not a mistake in the labelling; it reflects how each product was studied and licensed. It is also the single most common source of confusion I see, particularly in people who moved from one to the other.

The rule that matters more than the window

Never take two doses close together to catch up.

The instinct is to make up the missed dose. Do not. These drugs accumulate — a weekly injection lands on top of what remains of the last one, and the level climbs across several cycles before reaching steady state, which is why the standard titration interval is four weeks. Stacking two doses inside a couple of days produces a peak concentration the schedule was designed to avoid, and the result is usually a genuinely unpleasant few days of nausea and vomiting. The pharmacology behind this is in how long these drugs stay in your system.

If you are outside the window, skip it. One missed weekly dose is a minor event.

The longer gap, and the mistake people make

This is the part that gets people hurt.

If you have been off the drug for a few weeks — a holiday, a supply problem, an insurance gap, a hospital admission — do not simply resume at the dose you were on. Tolerance to the gastrointestinal effects fades, and it fades faster than most people expect. Restarting a 2.4 mg or 15 mg dose after a month off can produce the side effects of a first injection, at a dose four or five steps up the ladder.

Labelling for Wegovy advises considering reinitiation at a lower dose if two or more consecutive weekly doses are missed. Practically, my rule of thumb:

• 1 missed dose: resume as normal.
• 2–3 missed doses: speak to your prescriber; many people resume one step down.
• More than about 4 weeks off: expect to re-titrate, often from a low dose, and plan for it rather than being surprised.

Supply interruptions are common enough that this is worth knowing in advance. If you can see a gap coming, ask your prescriber what the restart plan is before it happens.

Changing your injection day

Entirely normal, and there is a constraint: a minimum interval between injections, commonly at least 48 hours for semaglutide products and at least 72 hours for tirzepatide.

So you shift gradually. Moving from Sunday to Thursday is a three-day move you can make in one step for semaglutide; moving Sunday to Monday is a one-day move you make by going the long way round — Sunday, then the following Monday, an eight-day gap, which is fine.

Good reasons to move your day: getting the difficult 24–48 hours after an injection onto a day you are not working, or away from a weekend you care about. Most people can identify their pattern within two dose cycles, which is one of the more useful things a log gives you.

What to do about the week itself

A missed dose usually means appetite returns partway through the week. That is a normal consequence, not a failure, and it is worth handling deliberately: keep protein at target even when hunger comes back, because the temptation is to treat the returning appetite as an event rather than as a Tuesday. The numbers are in muscle is the whole game.

Do not compensate by eating less than usual afterwards. And do not read one hungry week as evidence that the drug has stopped working — a single missed dose in a 52-week treatment is noise.

For what a dose change actually feels like from the inside, the first dose increase covers the week I was least prepared for.

If the missed doses are not your choice — a pharmacy with none in stock, a formulary change, an insurance gap — the restart arithmetic is the same but the planning is different: what to do in a GLP-1 shortage.

If you keep missing doses

Missing doses repeatedly is worth treating as information rather than as a discipline problem. The usual causes are practical: the injection day lands badly, the pen lives somewhere you do not look, the reminder is on a phone you silence, or the side effects in the day after are bad enough that some part of you is avoiding it.

All four have solutions, and the last one has a specific one — a slower titration, which is a prescriber conversation and the most effective intervention available for tolerability. Nobody should be quietly skipping doses to avoid a bad day when the dose schedule itself is adjustable.