Wegovy is semaglutide, given as a weekly injection and licensed for weight management, supplied in pre-filled pen devices. Because it is used once a week rather than daily, a pen can last for several weeks, which makes it easy to lose track of exactly how many injections are left — until the week you reach for a pen and are not sure whether it has one more dose in it or none.

The exact number of doses in a given pen depends on the specific product and packaging you have been prescribed, so this page will not state a figure for you to rely on. That number is printed on your pen and its packaging, and it is also confirmed by your pharmacist. Always check your own labeling rather than assuming it matches something you have read elsewhere, including a figure a friend or an online forum may have mentioned for a different product or pack size.

A simple way to keep count

  • The date you started using each new pen
  • The date of every injection you take from that pen
  • A running count of injections used from that pen, alongside the total your packaging states it should provide
  • The date you expect to need a new pen, based on your weekly schedule and how many doses remain
  • The date you actually opened or started each new pack, in case it differs from when the prescription was collected

A simple tally — a line added to a note or spreadsheet each week — is usually enough. You do not need anything elaborate; you need something you will actually keep up, and something that is quick enough to update that you will not be tempted to skip a week and lose track.

Why this helps with reordering

Prescriptions and pharmacy supply can take time to arrange, and running out unexpectedly is disruptive, particularly if a pharmacy needs to order stock in or a repeat prescription needs authorising by a prescriber first. Knowing roughly how many weeks of injections you have left, and translating that into a calendar date, gives you a clear point at which to arrange your next prescription or collection before you are down to your last dose, rather than finding out on the week you need it.

Some people find it useful to set a reminder a couple of weeks before their pen is expected to run out, based on their own tally, rather than waiting until the pen itself signals it is close to empty.

If your count and your pen do not match

If your own tally does not match what the pen appears to contain, or if a pen seems to be running low sooner than expected, do not guess or try to make it stretch further than intended by skipping or delaying doses. Check the patient information leaflet that came with your pen, and if anything is unclear, contact your pharmacist or prescriber. They are the right people to confirm how your specific pen and prescription are meant to work, and they can also advise if a pen appears faulty or under-filled.

Keeping track across repeat prescriptions

Over months of use, it is easy to lose the thread of exactly how many pens you have gone through, when each one started, and whether your supply pattern has stayed consistent. A running log — even a simple one that just lists a start date for every pen you use — builds into a useful history over time, and it can be a quick way to answer a pharmacist's question about how long you have been using your current pack without needing to check the packaging itself.

This kind of record is also useful if you ever need to explain a gap in treatment, such as a delayed prescription or an interrupted supply, since you will have a clear, dated account of when doses were actually taken rather than an approximate memory of it that gets harder to reconstruct the further back you try to remember.