Step-By-Step Instructions For Using Your Wegovy Injection Pen Safely

MedExpress can help you achieve lasting weight loss results with medications like Wegovy. However, it's important you take weight loss injections correctly to make sure you receive the full dose and reduce the risk of discomfort. This is our guide to taking Wegovy at home, so you can feel confident administering injections yourself and take control of your weight loss journey.

Article Summary:

• Wegovy is a self-injectable weight loss treatment containing semaglutide, a GLP-1 medication.
• It comes in a pre-filled pen that you can inject yourself at home.
• The medication is injected into your stomach, upper arm or thigh once a week. Rotate your injection site for each dose.

What is Wegovy?

Wegovy is the brand name for a prescription medication containing semaglutide. It’s made by Novo Nordisk, a global healthcare company. Semaglutide was originally developed to help manage type 2 diabetes, but it’s now also used to treat weight loss. This is what Wegovy was specifically created for.

To be prescribed Wegovy for weight loss or obesity, you must have a BMI of 30 or higher, or a BMI of 27 or higher if you also have a weight-related health problem like high blood pressure, type 2 diabetes, or high cholesterol.

How does Wegovy work?

Wegovy contains the active ingredient semaglutide, a type of drug known as a GLP-1 receptor agonist. It mimics a natural hormone in your gut, which helps to regulate your blood sugar levels, reduce your appetite and make you feel full for longer. This helps to reduce your body weight by decreasing overall calorie intake. You can find out more about how Wegovy works here, as well as the benefits and possible risks of taking semaglutide.

Combined with a healthy diet and regular physical activity, clinical trials show that Wegovy could help you lose 20.7% of your body weight on average in 72 weeks (1 year, 5 months). [1]

It’s also been proven in clinical studies to be helpful for cardiovascular health conditions. In a large study lasting just over three years, people who were overweight or obese and had existing heart disease took a weekly 2.4mg dose of semaglutide. The study found this reduced the risk of heart-related death, non-fatal heart attack, or stroke by 20%. [2]

How to take Wegovy

You take Wegovy on the same day each week. Try to take every injection at roughly the same time of day, and set reminder alerts for yourself, so it becomes part of your routine. This will help minimise the risk of you forgetting to take a dose.

Your healthcare provider will create a treatment plan that gradually increases your Wegovy dose, to help your body to adjust and reduce the risk of side effects.

Wegovy starts at a low dose (0.25mg). Your dose may increase every four weeks, until you reach your maintenance dose for ongoing weight management. At MedExpress, our clinicians review your progress regularly and will only adjust your dose if it’s safe, appropriate, and helping you make steady progress. We’ll keep you informed every step of the way with reminders and guidance designed to make treatment simple and supportive.

There’s no single “right” dose for everyone. Your clinician will work with you to find what feels best, balancing comfort, side effects, and results. Some people stay on a lower dose for longer, while others move up over time. The goal is to help you feel well, manage side effects, and see sustainable progress at a pace that suits you.

With MedExpress, you’ll receive 1 Wegovy injector pen each month, containing 4 doses. You'll also receive 4 disposable needles, and you must use a new one each time you inject.

Your first order will include:

• 1 x medication pen
• 4 x disposable needles
• Sharps disposal box
• Patient information leaflet
• Welcome booklet

Your step-by-step guide to using the Wegovy pen:

1. Check your pen

You should store your Wegovy pen in the fridge, between 2°C and 8°C. When it’s time for your dose, take your Wegovy pen out of the refrigerator at least half an hour before your injection so it can reach room temperature.

Check the injection pen to ensure:

• The medication name and dose is correct
• The pen isn't expired or damaged
• The medicine is clear and colourless

Don't use the pen if the medication is cloudy, coloured or contains any particles. You should also not use the pen if it has been frozen.

2. Wash your hands

Clean your hands with hot water and soap before every injection to reduce the risk of infection. If someone is injecting your dose for you, make sure they wash their hands.

3. Choose your injection site

You administer Wegovy as a subcutaneous injection, which means you inject it into the fatty tissue just under your skin. You should rotate your injection sites each week to prevent any skin irritation.

The recommended injection sites are:

• Stomach: Avoid scar tissue and stay at least two inches away from your belly button.
• Back of your upper arm: You may need someone to help you reach.
• Thigh: Inject into the front or side of your thigh.

When injecting, avoid any scars, moles, bruises, hard lumps, or irritated skin. When you've chosen your injection site, clean the area with the provided alcohol wipe and then let it air dry.

4. Prepare the pen

Wegovy comes as a pre-filled pen, but you need to prepare it with a new needle before each dose. Check your new needle to make sure it isn't damaged, the outer needle cap and paper tab should be intact to ensure the needle is sterile.

When you're ready for your dose, remove the paper tab, push the needle straight onto your pen and turn it to tighten. Remove the outer needle cap and keep it to one side as you'll need it later. Then, pull off the inner needle cover and dispose of it.

If this is your first dose from a new pen, you need to check the flow (this is called priming). If not, go straight to the next step.

To prime the pen, turn the dose selector until the flow check symbol (- - -) lines up with the dose pointer. Point the pen needle up and hold down the dose button until the dose counter returns to -0-. You should see a drop of medicine at the tip of the needle, and any air bubbles in the pen will be released. This drop indicates that the pen is ready for use.

If a drop does not appear, check the flow again. This should only be done twice. If there is still no drop, change the needle and check the flow once more. Do not use the pen if a drop of Wegovy still does not appear.

5. Injection

Before injecting, you need to set your dose. Turn the dose selector until you see your prescribed dose in the counter window. When the prescribed dose lines up with the dose pointer, the dose has been selected. Remember, if you are on the 7.2 mg once-weekly dose of Wegovy (3 injections of 2.4 mg), this will be "2.4 mg".

Insert the needle into your skin, making sure you can still see the dose counter window (you may need help with this if your injection site is difficult to reach). Press and hold the dose button until you see -0- in the dose window, then slowly count to six to ensure you receive the entire injection.

Once you've injected, carefully remove the needle from your skin and gently apply pressure with a cotton ball or gauze pad if there's any blood.

If you remove the pen before the counter hits 0 or before counting the full time, the dose may be incomplete. Do not re‑inject with the same pen, contact your prescriber for instructions.

6. Safely dispose of your pen

Lead the needle tip into the outer needle cap on a flat surface, without touching the needle. Once the needle cap is in place, push it to secure it. Never try to put the inner cap back on the needle, as you may stick yourself with the needle.

Twist the needle to remove it and dispose of it in a sharps container.

Always return your Wegovy pen to the fridge in between doses, making sure to keep the pen cap on to protect the medication from light and contamination.

What to expect after your Wegovy dose

You may notice some side effects after injecting your Wegovy dose, such as:

• Mild soreness, redness, or swelling at the injection site. This is very common and usually settles quickly.
• Headache, vomiting, diarrhoea, constipation, nausea, stomach pain and fatigue. These are all very common early side effects if you’re new to the treatment.
• Bloating, burping, farting, changes in taste, acid reflux, and dizziness. These are common side effects if you’re new to the treatment.

Call 999 or go to A&E immediately if you experience any of the following:

• Severe vomiting (3 times or more in one day) and/or:
  • Your vomit contains something that looks like coffee granules
  • Your vomit contains blood
  • You have a fever alongside your vomiting
• Severe stomach pain. Severe means:
  • It’s so intense (around 8 or more out of 10) that you can’t focus on anything else
  • It makes it nearly impossible to handle normal daily tasks (like walking, getting dressed, or eating)
  • It doesn’t improve with over-the-counter pain relief or rest
  • It radiates to your back or underneath your right ribcage or your right shoulder
  • You also have severe vomiting (3 or more times a day)
• Severe pain underneath your right ribcage that may spread to your shoulder or back, especially if you also have:
  • Vomiting
  • A high temperature
  • A rapid heartbeat
  • Dizziness and your face, arms or legs feel numb or weaker than usual.
  • Difficulty breathing, or swelling of the lips, tongue, or throat.
• Signs of very low blood sugar in someone who is unresponsive or not behaving normally, including:
  • Dizziness
  • Irritability
  • Confusion
  • Rapid heartbeat
  • Sweating

Practical tips for after your Wegovy injection

Your weight loss treatment might take a bit of time to get used to, but there are things you can do to help your body to adjust and to minimise side effects.

• Eat smaller, slower meals, and stop when you feel comfortably full rather than finishing the plate.
• Choose bland, low‑fat foods if nauseated (e.g., toast, crackers, potatoes) and sip fluids regularly to avoid dehydration.
• Avoid large, high‑fat or rich meals, too much alcohol, and heavy exercise immediately after big meals, as these can worsen nausea.
• Take your injection on the same day each week, for example every Sunday. Try and aim for roughly the same time on that day to establish a routine.
• Don’t take extra doses if you feel nothing, as this increases side‑effect risk without improving results.

What to avoid when taking Wegovy

• Your Wegovy pen contains glass parts, so you shouldn't use it if it's been dropped.
• Keep the pen cap on until you're ready to inject, to protect the medication from light.
• Never share your Wegovy pen with anyone else, even if it’s with a fresh needle.
• Don’t skip or delay doses regularly. Inconsistent weekly dosing can slow your results and increase risk of side effects.
• Don’t double up if you miss a dose. If it’s been more than 5 days, you should skip and wait for the next scheduled dose.
• Don’t inject into the exact same spot each week. Failing to rotate can cause skin irritation.
• Don’t rub or massage the site after injecting. This can worsen redness and irritation. Instead, use gentle pressure on the area.

Your Wegovy pen comes with a patient information leaflet that contains detailed injection instructions. If you have any other questions about self-injecting, please reach out to our dedicated clinical team for advice.

What to do if you miss a dose of Wegovy

If you miss a dose, you can take it within 5 days of your scheduled dose. If more than 5 days have passed, skip the dose and stick to your normal dosing schedule. Never take a double dose to make up for missed injections as this can worsen side effects.

Looking for support with your weight loss goals?

If you're at the start of your weight loss journey, clinically proven treatments may help support your progress. Find out if you qualify today by completing an online medical consultation on MedExpress.

References

1. Lingvay I, Bergenheim SJ, Buse JB, Freitas P, Garvey WT, Harder-Lauridsen NM, Rosenstock J, Sahu K, Wharton S; STEP UP T2D trial group. Once-weekly semaglutide 7·2 mg in adults with obesity and type 2 diabetes (STEP UP T2D): a randomised, controlled, phase 3b trial. Lancet Diabetes Endocrinol. 2025 Nov;13(11):935-948. doi: 10.1016/S2213-8587(25)00225-6. Epub 2025 Sep 14. PMID: 40961953.
2. A. Michael Lincoff, Kirstine Brown‐Frandsen, Colhoun HM, Deanfield J, Emerson SS, Sille Esbjerg, et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. The New England Journal of Medicine [Internet]. 2023 Nov 11;389(24). Available from: https://www.nejm.org/doi/10.1056/NEJMoa2307563