What If I Miss My GLP-1 Shot: Timing and Safety Guidance

Missing a GLP-1 injection is a common concern for people using medications such as semaglutide (Ozempic, Wegovy), dulaglutide (Trulicity), or liraglutide (Victoza, Saxenda). Whilst a single missed dose typically does not cause immediate harm, understanding the correct steps to take is essential for maintaining effective diabetes management or weight control. The guidance varies depending on which GLP-1 medication you use and how much time has passed since your scheduled injection. This article explains what happens when you miss a dose, when to take a missed injection, and practical strategies to help you maintain consistent treatment.

What Happens If You Miss a GLP-1 Injection

Missing a single GLP-1 (glucagon-like peptide-1) receptor agonist injection is a common occurrence and typically does not cause immediate harm. GLP-1 medications, such as semaglutide (Ozempic, Wegovy), dulaglutide (Trulicity), and liraglutide (Victoza, Saxenda), work by mimicking a naturally occurring hormone that regulates blood glucose levels and appetite. These medications have varying half-lives, meaning they remain active in your system for different durations after injection.

When you miss a dose, the medication level in your bloodstream gradually decreases. For weekly injections like semaglutide or dulaglutide, the effects may persist for several days due to their extended half-lives. However, as the drug concentration falls, you may notice a temporary return of symptoms that the medication was controlling. This might include increased appetite, higher blood glucose readings (if you have type 2 diabetes), or reduced feelings of satiety.

It is important to understand that missing one injection does not undo your overall progress or cause permanent setbacks. Your body will not experience withdrawal symptoms, as GLP-1 agonists are not addictive substances. However, if you are using these medications for diabetes management, you should monitor your blood glucose levels more frequently during the period when you have missed your dose, as glycaemic control may be temporarily affected.

The key concern with missed doses is maintaining consistent therapeutic levels for optimal disease management. If you miss multiple consecutive doses or frequently forget injections, this can compromise the effectiveness of your treatment regimen and may lead to suboptimal glucose control or weight management outcomes. Some GLP-1 medications require re-titration (restarting at a lower dose) after prolonged interruptions—for example, liraglutide (Saxenda) requires re-titration if missed for more than 3 days, and semaglutide (Wegovy) may need re-titration after multiple missed doses.

Should you have any concerns about a missed dose, contact your GP or diabetes specialist nurse for personalised advice.

When to Take Your Missed GLP-1 Dose

The timing guidance for taking a missed GLP-1 injection depends on which specific medication you are prescribed and how much time has elapsed since your scheduled dose. Each GLP-1 agonist has manufacturer-specific instructions that you should follow, as outlined in the patient information leaflet.

For weekly GLP-1 injections, the guidance varies by product:

Semaglutide (Ozempic, Wegovy):

• If you remember within 5 days of your missed dose, take the injection as soon as possible, then resume your regular weekly schedule.

• If more than 5 days have passed, skip the missed dose entirely and take your next injection on the originally scheduled day.

• If changing your regular injection day, ensure at least 48 hours between doses.

Dulaglutide (Trulicity):

• If you remember and at least 3 days (72 hours) remain before your next scheduled dose, take the injection as soon as possible.

• If less than 3 days remain before your next scheduled dose, skip the missed dose and take your next injection on the originally scheduled day.

• If changing your regular injection day, ensure at least 72 hours between doses.

For daily GLP-1 injections such as liraglutide (Victoza, Saxenda):

• If you remember within 12 hours of your usual time, take the injection as soon as you recall.

• If more than 12 hours have passed, skip the missed dose and resume your normal schedule at the next usual time.

• Do not take an extra or double dose to make up for a missed dose.

For liraglutide (Saxenda) specifically, if you miss doses for more than 3 days, you should restart at the initial dose of 0.6 mg and follow the dose escalation schedule again.

These timing windows are designed to maintain relatively stable drug levels whilst minimising the risk of adverse effects from taking doses too close together. The MHRA-approved product information for each medication provides specific guidance, and your prescriber should have discussed this with you when initiating treatment.

If you are uncertain about whether to take a missed dose, contact your GP surgery or diabetes specialist team for advice rather than guessing. They can review your individual circumstances, including how long you have been on the medication and your current dose, to provide tailored recommendations.

Should You Double Your Next GLP-1 Injection

You should never double your GLP-1 injection dose to compensate for a missed injection. This is a crucial safety principle that applies to all GLP-1 receptor agonists. Taking a double dose significantly increases your risk of experiencing adverse effects without providing additional therapeutic benefit.

GLP-1 medications are associated with dose-dependent side effects, particularly gastrointestinal symptoms. The most common adverse reactions include nausea, vomiting, diarrhoea, abdominal pain, and constipation. These effects are typically most pronounced when starting treatment or increasing the dose. By doubling your injection, you effectively create a sudden, substantial increase in drug concentration that your body has not been gradually adjusted to tolerate. This can trigger severe nausea and vomiting, which may lead to dehydration and electrolyte imbalances.

Additionally, taking an excessive dose of GLP-1 medication may increase the risk of hypoglycaemia (low blood glucose), particularly if you are also taking other diabetes medications such as insulin or sulfonylureas. When used alone, GLP-1 agonists rarely cause hypoglycaemia, but the risk increases significantly when combined with these other medications. Symptoms of hypoglycaemia include trembling, sweating, confusion, palpitations, and in severe cases, loss of consciousness.

The prescribing information for all GLP-1 medications explicitly states that missed doses should not be compensated for by increasing subsequent doses. The dose escalation schedules used when initiating these medications are carefully designed to allow your body to adapt gradually, minimising side effects whilst achieving therapeutic levels.

If you have accidentally taken a double dose, contact NHS 111 or your GP immediately for advice. Monitor yourself for signs of severe gastrointestinal symptoms and seek urgent medical attention if you experience:

• Persistent vomiting or inability to keep fluids down

• Severe, persistent abdominal pain (especially if radiating to the back, which could indicate pancreatitis)

• Symptoms of low blood sugar (if you take insulin or sulfonylureas)

• Signs of dehydration

If you experience any suspected side effects, you can report them via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

How to Avoid Missing Future GLP-1 Doses

Establishing a reliable routine is essential for maintaining consistent GLP-1 therapy and achieving optimal treatment outcomes. Several practical strategies can help you remember your injections and integrate them seamlessly into your daily or weekly schedule.

Set up reminder systems tailored to your lifestyle:

• Use smartphone alarms or calendar notifications set for your injection day and time

• Download medication reminder apps that send alerts and track your doses

• Set recurring reminders on smart home devices

• Ask family members to remind you on injection days

Create visual cues in your environment:

• Store your medication in a prominent location where you will see it (whilst maintaining proper storage temperature)

• Place a note on your bathroom mirror or refrigerator on injection days

• Keep your injection supplies in a designated, easily accessible location

Link injections to existing routines:

• For weekly injections, choose a consistent day that aligns with your schedule (e.g., every Sunday morning)

• For daily injections, pair the injection with an established habit such as brushing your teeth or having breakfast

• Use the same time of day for each injection to build muscle memory

Maintain adequate supplies:

• Request repeat prescriptions in advance to avoid running out

• Check your medication stock regularly

• Understand the NHS prescription ordering system at your GP surgery

• When travelling, ensure you have sufficient medication and proper storage solutions

Proper storage and disposal:

• Store unused pens in a refrigerator (2-8°C) before first use

• Follow in-use storage limits for your specific medication (check the patient information leaflet)

• Never freeze your medication or store with the needle attached

• Dispose of used needles and pens in a proper sharps container (available from your GP surgery or pharmacy)

Keep a medication diary or use the tracking features in diabetes management apps to record each injection. This creates accountability and helps you identify patterns if you do miss doses.

If you find yourself frequently forgetting doses despite these strategies, discuss this with your healthcare team. They can explore whether there are barriers to adherence that need addressing, such as injection anxiety, side effects, or practical difficulties with the injection device. In some cases, switching to a different GLP-1 formulation with a more convenient dosing schedule may be appropriate. NICE guidance emphasises the importance of shared decision-making in diabetes management, and your treatment regimen should be sustainable for your individual circumstances.

Frequently Asked Questions