What happens if you take two doses of Wegovy in one week

Step 1 — Work out exactly what happened before you do anything else

It sounds obvious, but the first thing worth doing is checking the pens themselves. Wegovy comes in pre-filled injectors with clear dose markings, and it is genuinely easy to confuse a new pen with the one you used last week, particularly if they are stored together in the fridge door. Look at the dose window: if both pens have been used, a double dose is likely. If the second pen is still full, you may not have taken a double dose at all.

Once you are confident a second dose has been given, note the time. Semaglutide absorbs over several hours, so whether you noticed the error immediately or the following morning changes the picture slightly. Write down the dose strength of each pen and when each injection happened. Your pharmacist or prescriber will want this information.

The Wegovy treatment overview on the nume site explains the licensed dosing schedule in plain terms, which can help you confirm where in your titration you were before the error occurred.

Step 2 — Understand what your body is likely experiencing

Semaglutide has a half-life of about seven days, which is why once-weekly dosing works. A second dose taken within the same week does not simply cancel or replace the first; the two amounts overlap in your system. The result is a higher peak concentration than intended.

For most people, this shows up as a worsening of the gastrointestinal effects already linked to Wegovy: stronger nausea, more vomiting, looser stools, heartburn and fatigue. According to the NHS patient information page for semaglutide, these effects are among the most commonly reported even at the correct dose, so a transient intensification after an accidental extra dose is the most likely scenario for most people. If you want to understand more about what taking 2 doses of Wegovy means for your body, we cover that in detail separately.

Stay hydrated. Small sips of water taken regularly matter more than large amounts at once if nausea is severe. Eating anything will probably feel unappealing, and that is fine for a short period, but prolonged inability to keep fluids down is a reason to contact 111 or your GP rather than wait it out.

Concerns about how the cost of treatment factors into any decision to restart or continue are worth raising at your consultation; you can find context on what Wegovy costs in the UK and what affects that price.

Step 3, Know the symptoms that need urgent medical attention

Most people who accidentally take two doses will feel rough for a day or two and then recover without any lasting effect. There are some symptoms, though, that need more than watchful waiting.

Severe, persistent stomach pain that spreads towards your back, with or without vomiting, can be a sign of acute pancreatitis. The MHRA issued a Drug Safety Update in January 2026 specifically highlighting acute pancreatitis as a known, if uncommon, risk with GLP-1 medicines: the guidance advises seeking urgent medical help if this pattern of pain develops. Do not assume it is ordinary nausea and wait for it to pass.

Repeated vomiting that stops you keeping any fluid down raises the risk of dehydration and, in people with certain conditions, of kidney stress. Signs of dehydration include dizziness when you stand, a dry mouth and passing very little urine. These are reasons to call 111.

If you experience swelling of the face, lips, tongue or throat, or have difficulty breathing, this may suggest an allergic reaction and needs a 999 call. Any unexpected side effect can be reported to the MHRA through the Yellow Card scheme, whether you consider it serious or not. That reporting genuinely helps regulators spot emerging patterns.

Step 4, Reset your schedule and contact your prescriber

Once the immediate situation is managed, your injection calendar needs resetting. The rule is simple: your next dose is due exactly seven days after the accidental second dose, not after your original injection day. So if your usual day was Monday and the extra dose went in on Thursday, your next dose is the following Thursday.

Tell your prescriber what happened. This is not about getting into trouble; it is so they can note it in your record, check whether any dose adjustment is sensible, and update you on what to watch for before your next injection. A question our prescribers hear regularly is whether an accidental double dose means the current dose is too hard to manage: sometimes it is a practical error with a clear cause, sometimes it flags that the titration pace needs a second look. Either way, the clinical conversation is the right place to work that out.

If you are wondering whether an injectable form of Wegovy or the effect of stepping up to a higher dose is the right next move, that is equally a question for a prescriber rather than something to resolve by experimenting at home. It is also worth reading about what taking the highest dose of Wegovy involves before any decision about moving to that stage of the titration. You can also read about the full Wegovy dose schedule to understand how the titration is structured and why each step exists. If you would like a prescriber to review your situation properly, our team is available through a free consultation here.