Can I take Wegovy a day early?

You can change your weekly injection day if needed, as long as there are at least 3 days (72 hours) between two doses. After switching, keep to the new weekly day going forward. For missed doses, the rule is different: if you are within 5 days, take it as soon as you remember; if it has been more than 5 days, skip it and take the next dose on your usual day.

Why flexibility is built in

Wegovy is prescribed as a once-weekly injection. The idea is to give people a medicine that fits into everyday life while still maintaining steady levels of semaglutide in the body. Real life, of course, is not always predictable. Work schedules change, family commitments get in the way, and travel can disrupt routines. That is why the dosing instructions include room for flexibility. They are written to balance the convenience patients need with the safety standards regulators require.

Unlike many daily medicines where timing is critical, semaglutide’s long half-life — it stays active in the body for around a week — means small adjustments to the schedule can be made without losing effectiveness. But “small” is the key word here. Rules are in place to stop people from getting doses too close together or leaving gaps that are too wide.

The 3-day rule for changing days

If you want to move your injection day earlier, you must allow at least 72 hours (three full days) between doses. This ensures that the previous dose has been processed and reduces the risk of side effects caused by too much medicine circulating at once. For example, if your usual day is Sunday but you want to move to Thursday, the gap from Sunday to Thursday is four days, so that is safe. But if you injected on Sunday and tried to move to Tuesday, that is only two days apart and therefore not allowed.

Once you switch to the new day, that becomes your weekly routine. So if you decide Thursday works better for your lifestyle, you continue every Thursday going forward. Consistency after the switch is essential to keep things simple and avoid confusion.

The 5-day rule for missed doses

The rules for missed doses are slightly different:

• If you are within five days of your usual injection date, you should take the dose as soon as possible.

• If it has been more than five days, you skip the missed dose and wait until your next scheduled one.

This rule recognises that semaglutide stays in the body long enough that a late dose within the five-day window can still be effective. But beyond five days, the risk of overlap with the next scheduled dose becomes too high. Doubling up is never recommended because it does not improve weight loss and may increase nausea or vomiting.

Why timing matters

Semaglutide works by mimicking the GLP-1 hormone, helping regulate appetite and digestion. To be effective, it needs to be delivered at steady, weekly intervals. Too much medicine too close together increases side effects, while too long a gap reduces consistency and can blunt the results. The 3-day and 5-day rules were tested during clinical trials and written into the official guidance so that people can manage everyday disruptions without undermining their treatment.

NHS perspective

NHS weight-management services know that no one’s routine is perfect. That is why they emphasise the rules clearly during first-dose training. Clinicians encourage people to pick a weekly day that will work most of the time — often tied to a regular event like Sunday evening or a weekend morning. But they also reassure patients that if life gets in the way, moving a day or catching up within the five-day window is safe. For people with irregular schedules, such as shift workers, clinicians may help plan a routine that still keeps doses spaced consistently.

Practical tips for staying on track

Patients often find a few simple habits make a big difference:

• Set reminders on a phone or calendar so you don’t forget.

• Write the date on the carton when you inject, to keep track of your schedule.

• Tie your injection to a weekly routine, like a specific meal or weekend activity.

• If travelling, adjust reminders to the local time zone to stay on schedule.

By planning ahead, you reduce the chance of missed or misplaced doses. These practical strategies are part of the support provided in NHS services, where education is considered as important as the medicine itself.

What this means in practice

Yes, you can take Wegovy a day early if there are at least three days between doses. If you miss a dose, the five-day rule decides whether you can take it late or wait until the next one. These simple rules give enough flexibility for real life while keeping treatment safe and effective. With NHS guidance, reminders, and a steady routine, most people find that once-weekly dosing soon becomes second nature.