Missed doses: the catch-up windows, product by product

This page is medicine information rather than an advert. Semaglutide, tirzepatide, liraglutide and orforglipron are prescription only medicines in the UK ^[7], and whether any of them is suitable is a decision for a prescriber after an assessment.

Missed doses are common and the rules are not intuitive, largely because they differ between products that people assume behave alike. The windows below come from the UK Summaries of Product Characteristics, which are the licensed documents.

The one rule that applies to everything

Never double up. No UK SmPC for any of these products permits taking two doses to make up for a missed one. Where a catch-up window has been missed, the dose is skipped and the normal schedule resumes. The dose is not brought forward permanently either — you return to your usual day.

Weekly injections

Semaglutide (Wegovy), all strengths including 7.2mg. If a dose is missed, it should be administered as soon as possible and within five days after the missed dose. If more than five days have passed, the missed dose should be skipped, and the next dose administered on the regularly scheduled day ^[1].

Tirzepatide (Mounjaro). The window is shorter: as soon as possible within four days after the missed dose. If more than four days have passed, skip the missed dose ^[2].

Ozempic follows the same five-day rule as Wegovy.

Four days versus five is a small difference that matters if you are working from something you read about the other product. The two are not interchangeable in this respect, any more than they are in mounjaro vs wegovy more generally.

Changing your injection day

Both products allow the day of the week to be moved.

Wegovy: the day of weekly administration “can be changed, if necessary, as long as the time between doses is at least three days“, meaning more than 72 hours ^[1].

Mounjaro: also at least three days between doses ^[2].

The practical point is to move the day deliberately, in one planned step, rather than letting it drift by a day at a time. Drifting is how a Sunday dose becomes a Wednesday dose and then someone takes two in five days without noticing.

Daily injection

Liraglutide (Saxenda). If the dose is remembered within about 12 hours of the usual time, take it. If less than 12 hours remain before the next scheduled dose, skip it. Do not take an extra dose and do not increase the next dose to make up ^[3].

There is an additional rule here that does not apply to the weekly products: if more than three days of doses are missed, treatment should be re-initiated at 0.6mg and re-titrated. That is an explicit SmPC instruction rather than general practice, which makes it unusual. Saxenda liraglutide covers the titration schedule.

The oral tablet: no catch-up window

This is the clearest contrast in the whole subject, and the one most often got wrong.

Wegovy 25mg tablets (oral semaglutide for weight management), with escalation running 1.5, 4, 9 then 25mg in monthly steps: “If a dose is missed, the missed dose should be skipped, and the next dose should be taken the following day” ^[4].

There is no catch-up window at all. Not five days, not one day, not later the same day. Miss it, skip it, resume tomorrow. Rybelsus carries the same skip rule ^[5].

The reason lies in how the tablet is absorbed, which also explains its administration requirements:

• taken on an empty stomach after a fast of at least 8 hours
• swallowed whole with a sip of water, up to half a glass, 120mL
• not split, crushed or chewed
• then at least 30 minutes before eating, drinking or taking any other oral medicine
• one tablet per day only

Those conditions are narrow enough that “taking it later” usually means taking it under conditions where absorption would be unreliable. Skipping is the licensed answer. Wegovy tablets covers the wider comparison between the oral and injectable forms.

Orforglipron (Foundayo), approved by the MHRA in August 2026, is a once-daily oral non-peptide agent with no food or water restrictions ^[6]. It is not NHS-funded, and a NICE appraisal is expected in November 2026. See orforglipron (Foundayo).

After a longer gap

Missing one dose is a schedule question. Missing several weeks is a clinical one.

After a prolonged gap — commonly cited as more than two missed weekly doses — re-titration from a lower dose is frequently advised to limit gastrointestinal effects, because tolerance to nausea and related symptoms builds during titration and is lost during an interruption.

It is worth being precise about the status of that advice. It is common clinical practice and manufacturer support-line advice, rather than an explicit SmPC instruction for every weekly product. The daily liraglutide product does carry an explicit re-titration instruction after more than three days; the weekly injectables generally do not spell out an equivalent rule. That is why the answer to “can I just pick up where I left off after a month away” is a conversation with your prescriber rather than something to decide from a leaflet.

Do not resume a higher dose than you were previously tolerating, and do not stop or restart treatment on your own initiative. Raise gaps with your prescriber, particularly if they are becoming a pattern, since a supply or tolerability problem is usually the fixable thing underneath.

Practical ways to miss fewer

• Set the reminder for the dose day, not for the day you collect the medicine
• Keep a written or app record of the date and site of each injection; the record for injection technique and sites rotation does both jobs
• Before travel, check the dose date against the trip, and check the storage requirements for your product
• Order repeat supplies at a fixed point in the cycle rather than when the pen runs out
• If you are on the oral tablet, anchor it to waking rather than to breakfast, since the 8-hour fast and 30-minute wait are the parts that get squeezed

When to speak to a clinician

• Two or more missed weekly doses, before restarting at your previous dose
• Persistent vomiting or inability to keep fluids down, which needs same-day assessment
• Severe abdominal pain, particularly pain radiating to the back — go to A&E
• Repeated missed doses because of cost, supply or side effects, which is worth raising directly rather than managing alone

This article is for general information and isn’t a substitute for advice from your own clinician. If you feel unwell, contact your GP or NHS 111. In an emergency, call 999.