The Trulicity pen is a single-use, pre-filled injection device for administering dulaglutide, a GLP-1 receptor agonist used in type 2 diabetes management. Many patients wonder how to reset a Trulicity pen after use, but it's crucial to understand that this device is specifically engineered to prevent resetting or reuse. The pen's design incorporates irreversible mechanical components and safety features that activate only once, ensuring accurate dosing and sterility. This article explains why the Trulicity pen cannot be reset, what to do if your pen malfunctions before injection, proper disposal methods, and correct injection technique to avoid issues.

Understanding the Trulicity Pen Design and Mechanism

Trulicity (dulaglutide) is a once-weekly injectable medication used to manage type 2 diabetes mellitus. It belongs to the glucagon-like peptide-1 (GLP-1) receptor agonist class, which works by stimulating insulin secretion in response to elevated blood glucose levels, suppressing glucagon release, and slowing gastric emptying. The Trulicity pen is a single-use, pre-filled injection device designed to deliver a fixed dose of 0.75 mg, 1.5 mg, 3 mg, or 4.5 mg of dulaglutide subcutaneously.

The pen features a design that prioritises patient safety and ease of use. Unlike traditional insulin pens with replaceable cartridges, the Trulicity pen is entirely disposable after one injection. The device contains a hidden needle mechanism that automatically inserts and retracts, minimising needle anxiety and reducing the risk of needlestick injuries. The injection mechanism activates only when you press the green injection button after placing the pen against your skin.

The pen's internal components include a spring-loaded plunger system, a pre-filled medication reservoir, and a sterile needle assembly. Once the green button is pressed and held, the device delivers the full dose over several seconds, indicated by a click and the appearance of a grey plunger in the viewing window. This single-use design is intentional and incorporates multiple safety features to prevent reuse, contamination, or incorrect dosing.

Understanding this mechanism is crucial because it explains why the pen cannot be reset or refilled. The device is engineered as a closed system where all components work in a single, irreversible sequence to ensure accurate medication delivery and patient safety. Importantly, Trulicity pens must never be shared with other people, even if the needle is changed.

Why the Trulicity Pen Cannot Be Reset After Use

The Trulicity pen is specifically designed as a single-use device and cannot be reset, refilled, or reused under any circumstances. This design philosophy is rooted in patient safety, medication integrity, and regulatory compliance. Once the injection mechanism has been activated, the internal components undergo irreversible changes that prevent any further use.

Several technical factors make resetting impossible. Firstly, the spring mechanism that drives the plunger to deliver medication cannot be re-tensioned once released. The mechanical energy stored in the spring is completely expended during the injection process. Secondly, the needle assembly is designed for single penetration only; attempting to reuse it would compromise sterility and significantly increase infection risk. The needle also becomes dulled after initial use, which would make subsequent injections more painful and potentially less effective.

From a pharmaceutical perspective, once the pen's seal is broken and the medication is exposed to the needle pathway, the sterility of the remaining contents cannot be guaranteed. Even if medication appears to remain in the reservoir, microbial contamination becomes a serious concern.

Trulicity is authorised and labelled as a single-use, prefilled pen, and reuse is contraindicated according to the UK Summary of Product Characteristics (SmPC) and Patient Information Leaflet (PIL). The single-use design ensures consistent dosing accuracy, eliminates the risk of cross-contamination between doses, and prevents medication errors that could occur with reusable devices. Attempting to manipulate or reset the pen would void these safety assurances and could result in serious health consequences, including infection, incorrect dosing, or medication degradation.

What to Do If Your Trulicity Pen Malfunctions Before Injection

If you suspect your Trulicity pen has malfunctioned before you have completed your injection, it is essential to follow specific steps to ensure your safety and maintain your treatment schedule. A malfunction might include the pen not clicking, the plunger not appearing in the window, medication leaking from the pen, or the pen activating accidentally before proper placement.

Immediate steps to take:

• Do not attempt to use the pen again if it has partially activated or appears damaged

• Check the viewing window to see if the grey plunger is visible, which indicates the dose has been delivered

• If you are uncertain whether you received your full dose, do not administer another injection immediately

• Note the batch number and expiry date from the pen label for reporting purposes

• Store the malfunctioning pen safely for potential inspection, but keep it away from children

If the malfunction occurred before any medication was delivered (confirmed by no grey plunger visible and no click heard), you may use a new pen from your supply if available. However, if you are unsure whether you received a partial or full dose, contact your GP, practice nurse, or diabetes specialist team before taking any further action. If uncertain whether a full dose was given, check your blood glucose more frequently, especially if you also use insulin or sulfonylureas, as these medications increase the risk of hypoglycaemia.

If you miss a dose due to pen malfunction, and your next scheduled dose is 3 or more days away, take the missed dose as soon as possible. If your next scheduled dose is less than 3 days away, skip the missed dose and take your next dose on the usual day.

You should report the malfunction through the Yellow Card Scheme (yellowcard.mhra.gov.uk), which allows patients and healthcare professionals to report suspected problems with medicines and medical devices directly to the MHRA. Additionally, contact the manufacturer's medical information line or your pharmacist, who can provide guidance and arrange for a replacement pen if necessary.

Safe Disposal and Obtaining a Replacement Trulicity Pen

Proper disposal of used Trulicity pens is essential for environmental protection and public safety. The pen contains a needle and residual medication, classifying it as pharmaceutical waste that requires careful handling. Never dispose of used pens in household rubbish or recycling bins, as this poses needlestick injury risks to waste handlers and potential environmental contamination.

The recommended disposal method involves using a sharps container (also called a sharps bin), which is a puncture-resistant, clearly labelled container specifically designed for used needles and injection devices. Your GP surgery, diabetes clinic, or community pharmacy can typically provide information about obtaining a sharps container. Once your sharps container is approximately three-quarters full, seal it according to the instructions and return it according to local NHS or council guidelines. Disposal pathways vary across the UK, so check with your healthcare team or local council about specific arrangements in your area.

Important disposal guidelines:

• Follow the specific disposal instructions in the Trulicity Patient Information Leaflet

• Never attempt to remove the needle from the pen

• Keep sharps containers out of reach of children and pets

• Do not overfill the container, as this increases injury risk

If you need a replacement pen due to malfunction or damage, contact your prescribing healthcare professional or pharmacy. Your GP can issue a new prescription if needed, though you should explain the circumstances requiring early replacement. Most pharmacies maintain stock of Trulicity pens in various strengths, though occasionally supply issues may occur. If your usual pharmacy cannot provide a replacement immediately, they can often arrange transfer from another branch or suggest alternative local pharmacies.

For urgent replacement needs outside normal hours, contact NHS 111 for advice. They can direct you to appropriate services and provide guidance on managing your diabetes treatment until you obtain a replacement. If you miss a dose, follow the guidance in the Patient Information Leaflet regarding missed doses.

Proper Injection Technique to Avoid Trulicity Pen Issues

Mastering the correct injection technique significantly reduces the likelihood of pen malfunctions and ensures optimal medication delivery. Trulicity should be administered subcutaneously (under the skin) once weekly, on the same day each week, at any time of day, with or without food. The recommended injection sites are the abdomen (avoiding the area around the navel), the front of the thighs, or the outer area of the upper arms.

Step-by-step injection technique:

Preparation: Remove the Trulicity pen from the refrigerator 30 minutes before injection to allow it to reach room temperature, which makes the injection more comfortable. Inspect the pen through the viewing window to ensure the liquid is clear and colourless to slightly yellow. Do not use the pen if the liquid appears cloudy, discoloured, or contains particles. Wash your hands thoroughly and clean the injection site with an alcohol wipe if recommended by your healthcare team, allowing the skin to dry completely.

Administration: Remove the base cap from the pen. Place the pen firmly against your skin at a 90-degree angle, ensuring good contact. Press and hold the green injection button until you hear a click, then continue holding the pen in place until you hear a second click, which confirms the full dose has been delivered. You should see the grey plunger appear in the viewing window. Remove the pen from your skin and dispose of it according to the instructions in the Patient Information Leaflet.

Common mistakes to avoid:

• Not holding the pen firmly enough against the skin, which may prevent activation

• Removing the pen too quickly before the full dose is delivered (before the second click)

• Injecting through clothing rather than directly onto clean skin

• Using the same injection site repeatedly, which can cause lipohypertrophy (fatty lumps)

• Storing the pen incorrectly, which may affect medication stability

Rotate injection sites each week, maintaining at least 2.5 cm distance from the previous injection location. This practice prevents tissue damage and ensures consistent medication absorption.

Storage information: Store unused Trulicity pens in the refrigerator (2-8°C), do not freeze, and protect from light. If needed, the pen may be kept at room temperature (below 30°C) for up to 14 days.

If you experience persistent problems with pen activation or injection discomfort, request a demonstration from your practice nurse or diabetes specialist nurse, who can observe your technique and provide personalised guidance.

Frequently Asked Questions