A change of medicine is a prescribing decision, and if you have been moved from Zepbound to Wegovy that decision has already been made by someone holding your full history. Nothing on this page will tell you how the change is done, and nothing here is a reason to alter what you have been asked to do. Questions about why the change was made, or what happens in the weeks around it, go to the prescriber or pharmacist who arranged it. What follows is only about your own notebook.

These are two different medicines licensed for the same purpose. Zepbound is tirzepatide, taken as an injection once a week and licensed for weight management. Wegovy is semaglutide, licensed for weight management as well, and official labelling covers it in more than one presentation: an injection given once a week, and tablets taken by mouth. Which of those you have been given is settled by your own prescription and the pack it produced, not by anything written here.

That matters for the shape of the record as well as its accuracy. If both of your products are injections, the outward routine tends to survive a change of this kind and the log can carry on looking much as it did. If the new pack is tablets, the routine itself changes and half of what you were recording no longer has anything to describe. Either way the molecule underneath has changed, and that is the reason a log kept straight through the change can quietly stop meaning anything.

Close the old record deliberately

Most people simply carry on writing in the same place and later cannot say where one medicine ended and the next began. A closing entry, written while the last weeks are still fresh, fixes that. It takes ten minutes and it is the single most useful thing you can do in the days around a change.

  • The date of your final Zepbound injection, written as a date rather than as a week number
  • The date the new prescription starts, and which presentation it turned out to be, copied from the pack rather than assumed
  • Your weight on a named day close to that date, taken the way you normally take it
  • Any measurements or photos you keep, dated, so there is a fixed point on both sides of the line
  • Which side effects, if any, were still present in the last month, and roughly how strong they were
  • How hunger and fullness felt in ordinary words, not scores: what a normal evening meal looked like, whether you were thinking about food between meals
  • Anything unresolved you had been meaning to raise, so it is not lost in the paperwork of a change

That last item matters more than it looks. A change of medicine tends to reset a conversation, and a question you had been carrying for two months can vanish simply because the next appointment is about something new.

Start a new page rather than a new line

Open a fresh section, tab, or page dated from your first dose of Wegovy, and leave the old one closed. The reason is not tidiness. If the two stretches run together in one continuous column, every later comparison silently mixes them, and a trend you spot in three months may be an artefact of the join rather than anything real. Kept apart, both stretches stay readable, and you can still lay them side by side whenever you want to.

In the new section, the first four to six weeks are worth recording more closely than you probably record a settled month. The things to catch are ordinary: the date of each dose, which days brought digestive symptoms and how long they lasted, what you managed to eat and what you could not face, how energy and sleep sat, and any questions as they occur to you rather than reconstructed later.

An old pattern is not a forecast

This is the part most people get wrong, and it is worth being blunt about. Tirzepatide and semaglutide have overlapping side-effect profiles on paper. MedlinePlus lists nausea, vomiting, diarrhoea and constipation among the reported effects for both, and MHRA continues to remind patients and clinicians alike to stay alert to what these medicines can do. Overlapping profiles are not the same thing as identical experiences, and none of it says anything about you specifically.

So the pattern you had learned to expect, whatever it was, is not evidence about the coming months. If your first medicine gave you a rough day or two after each dose, that rhythm may or may not repeat. If you had no trouble at all, that is not a guarantee either. Observe it from scratch, as though you had never tracked a GLP-1 before, and let the notes tell you what the pattern is rather than deciding in advance and only recording what fits.

MedlinePlus is explicit that symptoms which are severe, or which do not go away, are worth telling a doctor about. That advice does not soften because you have been through an adjustment period before and think you know what to expect.

What tends to get asked at the next review

Reviews after a change of medicine follow a fairly consistent shape, and knowing it in advance is why a closing entry is worth making. A prescriber will usually be trying to establish what is different, and vague impressions make that hard.

  • Where your weight sat immediately before the change and where it sits now, from your own dated readings
  • Which symptoms appeared, on which days relative to each injection, and whether they eased or persisted across the weeks
  • Whether anything else in your life changed at the same time, which is common and easily forgotten
  • An up-to-date list of everything else you take. FDA advises keeping a personal medicines list current and sharing it with the professionals treating you, and a change of prescription is exactly when such a list goes stale

Bring the notes as you wrote them. Summarising them into a verdict before the appointment throws away the detail that makes them useful, and a clinician can generally read a plain dated list faster than a paragraph of conclusions.

Where this page stops

There is no conversion table here, no equivalence between one medicine and the other, and no account of how a change is staged, because those belong to the person prescribing and to the patient information leaflet that comes with your medicine. If something you have read elsewhere contradicts what you have been told, the instruction you were given for your own treatment is the one that counts, and the discrepancy is worth raising rather than resolving on your own.

Get urgent medical help for severe or persistent vomiting, an inability to keep fluids down, severe abdominal pain, or signs of a serious allergic reaction such as facial swelling or difficulty breathing. Those are not things to note down and mention at your next appointment; the notebook is for everything else.