Taking weight loss injections is a big step, and it is completely normal to feel a little uncertain the first time you use your pen.
The good news is that modern injection devices are designed to be straightforward. With a bit of guidance, most patients feel confident within their very first use.
This guide walks you through the whole process, from picking up your pen at McMinns Pharmacy to delivering your weekly injection safely and effectively.
Collecting Your Pen from McMinns Pharmacy
Your weight loss injection will be dispensed by our team at McMinns Pharmacy following your initial consultation.
Depending on your treatment plan, this will be either a Mounjaro (tirzepatide) or Wegovy (semaglutide) pen. Both are pre-filled, single-use auto-injector devices.
When you collect your pen, our pharmacist will walk you through the basics and answer any questions you have.
Please make sure you have a suitable place to store it at home before you leave – more on that below.
How to Store Your Injection Pen
Correct storage is essential to keep your medication safe and effective. Follow these guidelines:
- Before first use: store your pen in the fridge at 2–8°C. Do not store it near the freezer compartment or against the back wall, as freezing will damage the medication.
- After removal from the fridge: the pen can be kept at room temperature (below 30°C) for up to 4 weeks (Wegovy) or up to 21 days (Mounjaro). Check the patient information leaflet for your specific product.
- Keep it out of direct sunlight: do not leave your pen on a windowsill or in a warm car.
- Never use a frozen pen: if your pen has been frozen, do not use it – contact McMinns Pharmacy for advice.
- Keep out of reach of children: store in a safe location and dispose of used pens in a sharps bin, which can be provided by our pharmacy team.
Preparing Your Injection Pen
Before you inject, take a few minutes to prepare properly. Good preparation makes the process smoother and reduces the risk of errors.
- Check the pen. Make sure you have the correct pen, the right dose, and that it is within its expiry date. Check the liquid through the viewing window. It should be clear and colourless. Do not use it if it appears cloudy, discoloured, or contains particles.
- Let it come to room temperature. If your pen has been in the fridge, take it out 15–30 minutes before injecting. Injecting cold medication can be more uncomfortable.
- Wash your hands. Wash thoroughly with soap and warm water for at least 20 seconds and dry well before handling the pen or touching the injection site.
- Remove the pen cap. Pull the cap off straight – do not twist. Keep it off only when you are ready to inject, as the needle is now exposed on most devices.
Preparing the Injection Site
Weight loss injections are administered subcutaneously – that means just beneath the skin, not into a muscle. There are three approved sites:
- Abdomen: at least 5 cm (2 inches) away from your navel – this is the most commonly used site
- Outer thigh: the fleshy outer area of the upper thigh
- Upper arm: the outer area of the upper arm (this site may be easier with assistance)
Rotate your injection site each week. For example, use the left abdomen one week, the right thigh the next. This prevents the skin from becoming hardened or irritated from repeated injections in the same spot.
Clean the chosen area with an alcohol swab and allow it to air dry fully before injecting. Do not inject into skin that is bruised, broken, red, or tender.
How to Deliver the Injection
Once your pen and skin are prepared, follow these steps to inject:
- Position the pen. Hold the pen firmly and press it flat against the cleaned skin at a 90-degree angle. You do not need to pinch the skin.
- Press and hold. Press the injection button firmly until you hear or feel a click. Keep the pen pressed flat against the skin – do not lift it away.
- Hold for the count. Hold the pen in place for a slow count of 10 seconds after the click. This ensures the full dose is delivered.
- Remove the pen. Lift the pen straight away from the skin. A small bleed or mark at the site is normal – press gently with a clean cotton pad if needed. Do not rub.
- Dispose safely. Place the used pen directly into your sharps bin. Never recap a used pen and never dispose of it in general household waste.
Dose Titration: Starting Low and Building Up
Both Mounjaro and Wegovy use a titration schedule – meaning you start on a low dose and gradually increase it over several weeks.
This approach is intentional: it gives your body time to adjust and significantly reduces the severity of side effects.
Typically, you will start on the lowest available dose for the first four weeks before stepping up to the next dose level.
Your prescriber will guide you through this schedule, and it is important not to increase your dose ahead of schedule, even if you feel you are tolerating the medication well.
At McMinns Pharmacy, we schedule regular follow-up reviews throughout your treatment so we can monitor your progress, assess tolerance, and advise on when to move to the next dose.
If side effects are persistent at a particular dose, it is sometimes appropriate to stay on that level a little longer before titrating up.
Potential Side Effects
As with any medication, weight loss injections can cause side effects. Most are mild and tend to improve as your body adjusts, particularly when following the titration schedule correctly.
Common side effects include:
- Nausea – the most frequently reported side effect, especially in the early weeks
- Vomiting
- Diarrhoea or constipation
- Reduced appetite (which is partly the intended mechanism of action)
- Fatigue
- Injection site reactions such as redness, mild swelling, or itching
Less common side effects can include heartburn, bloating, and burping. In rare cases, more serious reactions such as pancreatitis, gallbladder problems, or allergic reactions can occur.
If you experience severe abdominal pain, difficulty breathing, or a racing heartbeat, stop the medication and seek medical attention promptly.
Eating smaller, lower-fat meals and staying well hydrated can help manage gastrointestinal side effects.
Our team at McMinns Pharmacy can offer practical advice if you are struggling with any symptoms.
Support Throughout Your Journey at McMinns Pharmacy
Starting a weight loss injection programme is a commitment, and you do not have to manage it alone.
Our team at McMinns Pharmacy in Wishaw is here to support you from your first consultation through every follow-up review.
If you have questions about your pen, your dose, or any side effects, do not hesitate to get in touch.
You can book your free weight loss consultation online at mcminnspharmacy.co.uk/bookings, call us on 01698 372917, or pop in to see us in the pharmacy.