Bruising from Trulicity injection is a common, minor reaction that occurs when the needle punctures small blood vessels beneath the skin during subcutaneous administration. Trulicity (dulaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist used once weekly for type 2 diabetes management. Whilst injection site bruising can be concerning for patients, it typically resolves within 7–14 days without specific treatment and does not affect the medication's effectiveness. Understanding why bruising occurs, how to minimise its occurrence through proper injection technique, and when to seek medical advice can help patients manage this reaction confidently and maintain treatment adherence.

Why Bruising Occurs After Trulicity Injections

Trulicity (dulaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist administered via subcutaneous injection, typically once weekly for type 2 diabetes management. Bruising at the injection site is a recognised local reaction that occurs when the needle punctures small blood vessels (capillaries) beneath the skin surface, causing blood to leak into surrounding tissues.

Several factors contribute to bruising following Trulicity injections. The subcutaneous injection technique involves inserting a needle through the skin into the fatty tissue layer, where small blood vessels are naturally present. When a capillary is inadvertently nicked during injection, localised bleeding occurs, manifesting as a bruise (ecchymosis). The abdomen (avoiding a 5cm radius around the navel), the front of the thighs, and the outer upper arm are the recommended injection sites for Trulicity. Note that upper arm injections typically require another person to administer the injection, as stated in the Trulicity Patient Information Leaflet.

Individual patient factors also influence bruising susceptibility. People taking anticoagulant medications (such as warfarin, apixaban, or rivaroxaban) or antiplatelet agents (including aspirin or clopidogrel) have reduced clotting capacity, making bruising more likely. Similarly, those with naturally thinner skin, particularly older adults, may experience more visible bruising. Certain medical conditions affecting blood clotting or vessel integrity can increase bruising tendency.

It is important to note that bruising from Trulicity injections is generally a minor, self-limiting reaction unrelated to the medication's systemic effects. The bruising results from the mechanical action of needle insertion rather than any pharmacological property of dulaglutide itself. Most injection-site bruises resolve spontaneously within 7–14 days without requiring specific treatment.

How Common Is Bruising with Trulicity?

Injection site reactions, including bruising, are among the recognised adverse effects associated with Trulicity use, though they are generally classified as mild to moderate in severity. According to the Trulicity Summary of Product Characteristics (SmPC), injection site reactions are categorised as 'common' adverse effects, meaning they may affect up to 1 in 10 people. These reactions include bruising alongside redness, swelling, or tenderness.

The specific frequency of bruising as a distinct reaction is not separately categorised in clinical data, making it a subset of overall injection site reactions. Individual experiences may vary, and some patients may notice minor bruising that they do not report to healthcare providers.

Factors influencing bruising frequency include:

• Injection technique – familiarity with the Trulicity auto-injector device may affect outcomes

• Anatomical injection site selection – certain areas have more superficial vasculature

• Concurrent medication use – anticoagulants significantly increase bruising likelihood

• Individual tissue characteristics – skin thickness, subcutaneous fat distribution, and vessel fragility

Injection site reactions can occur with any subcutaneously administered medication, though rates vary between different products and delivery systems. The Trulicity auto-injector is designed to deliver the medication subcutaneously with a hidden needle that automatically inserts and retracts.

Most patients who experience bruising with Trulicity find that it becomes less frequent as they gain experience with the device and identify optimal injection sites on their body. The transient nature of bruising and its lack of association with treatment efficacy mean it rarely necessitates medication discontinuation.

Reducing Bruising Risk: Injection Technique Tips

Proper injection technique significantly reduces the likelihood of bruising and other injection site reactions when administering Trulicity. Healthcare professionals should provide comprehensive training to patients initiating Trulicity therapy, with particular attention to technique refinement for those experiencing recurrent bruising.

Site selection and rotation are fundamental to minimising bruising risk. Trulicity should be injected into areas with adequate subcutaneous fat: the abdomen (avoiding a 5cm radius around the navel), the front of the thighs, or the outer upper arm (with assistance from another person). Rotating injection sites with each weekly dose prevents tissue trauma accumulation in any single area. Patients should avoid injecting into areas with visible bruising, scarring, or skin abnormalities.

Pre-injection preparation can substantially reduce bruising:

• Allow the Trulicity pen to reach room temperature (approximately 30 minutes out of refrigeration) before injection for comfort

• Cleanse the injection site with an alcohol wipe and allow it to dry completely—injecting through wet alcohol can increase discomfort

• Visually inspect the injection area, avoiding sites with visible blood vessels near the surface

• Never inject through clothing

• Avoid areas where clothing waistbands or elastic may cause friction

Correct Trulicity pen technique includes:

• Unlock the grey base by turning it

• Place the clear base flat against the skin at a 90-degree angle

• Press and hold the green injection button

• Listen for the first click, then continue holding until you hear the second click (this may take up to 5-10 seconds)

• Remove the pen from the skin after the second click

Post-injection care involves applying gentle pressure (without rubbing) using a clean cotton wool ball or gauze for 5–10 seconds. Do not rub or massage the injection site as this may disperse medication and exacerbate bruising. Patients taking anticoagulants may benefit from slightly longer pressure application to facilitate haemostasis.

For detailed instructions, always refer to the Patient Information Leaflet provided with your Trulicity pen or consult the NHS website for guidance on injection technique.

When to Seek Medical Advice About Injection Site Bruising

Whilst minor bruising following Trulicity injection is generally benign and self-resolving, certain presentations warrant medical evaluation to exclude complications or underlying pathology. Patients should be educated about warning signs that distinguish normal injection site reactions from those requiring professional assessment.

Routine bruising typically presents as a small, well-defined area of discolouration (purple, blue, or yellow-green as it resolves) measuring less than 2–3cm in diameter. It should be painless or only mildly tender, without warmth, and should gradually fade over 7–14 days. This pattern requires no specific medical intervention beyond technique optimisation.

Seek GP advice on the same day if:

• The injection site becomes increasingly painful, warm, red, or swollen—suggesting possible infection (cellulitis)

• Bruising exceeds 5cm in diameter or continues expanding after 24 hours (as a practical guide)

• Bruising occurs with every injection despite proper technique

• New or worsening bruising appears at sites distant from injections

• Bruising is accompanied by unusual bleeding elsewhere (gums, nose, or gastrointestinal tract)

Seek urgent medical attention (call 999) if:

• Signs of severe allergic reaction develop: facial swelling, breathing difficulty, widespread rash, or dizziness

• The injection site develops signs of abscess formation: fluctuant swelling, severe pain, or purulent discharge

• Extensive bruising is accompanied by systemic symptoms: fever, malaise, or unexplained fatigue

• Sudden onset of multiple bruises without clear trauma, particularly in patients on anticoagulation

Patients taking anticoagulant medications should follow their specific monitoring requirements. Those on warfarin require regular INR monitoring, while those taking direct oral anticoagulants (DOACs) like apixaban or rivaroxaban need periodic clinical review and renal function tests. Healthcare providers should review injection technique with patients experiencing recurrent problematic bruising and consider whether medication factors (including other prescribed drugs affecting haemostasis) may be contributory. There is no established link between Trulicity and systemic bleeding disorders, but persistent injection site complications merit investigation to exclude unrelated haematological conditions.

Managing Bruising and Injection Site Reactions

Most bruising from Trulicity injections resolves spontaneously without specific intervention, but several strategies can help manage discomfort and promote healing. Patient education about appropriate bruise management promotes confidence in continuing therapy and reduces unnecessary anxiety.

Immediate post-injection management (first 24 hours) focuses on minimising haematoma expansion. Applying a cold compress or ice pack wrapped in a clean cloth to the injection site for 10–15 minutes several times during the first few hours can promote vasoconstriction, reducing blood leakage into tissues. Avoid applying ice directly to skin, which may cause cold injury. Gentle pressure without rubbing helps facilitate clotting at the puncture site.

Subsequent bruise care (days 2–14) aims to facilitate reabsorption of extravasated blood. After the first 24–48 hours, some patients find warm compresses helpful, though evidence for this practice is limited. Avoid tight clothing that might cause friction or pressure over the affected area, and do not massage or rub the bruise.

Medications and bruise healing:

• Paracetamol is appropriate for pain relief if needed

• If you regularly take non-steroidal anti-inflammatory drugs (NSAIDs), continue as prescribed, but avoid taking additional NSAIDs specifically for bruise-related discomfort, especially if you're also on anticoagulants

• Continue prescribed anticoagulants as directed—do not alter dosing without medical advice

• Topical treatments such as arnica or vitamin K creams are not routinely recommended due to limited evidence and potential for skin irritation

Documentation and pattern recognition can be valuable for patients experiencing recurrent bruising. Keeping a simple log noting injection sites, bruising occurrence, and any technique variations helps identify problematic areas or practices. This information assists healthcare providers in tailoring advice during follow-up consultations.

Patients should be reassured that injection site bruising does not affect Trulicity's glycaemic efficacy or increase the risk of systemic adverse effects. The medication is absorbed systemically regardless of minor local bruising. If bruising causes significant distress or affects treatment adherence, discussing concerns with the diabetes care team is important—alternative GLP-1 receptor agonists or delivery systems may be considered.

If you experience any suspected side effects from Trulicity, including unusual or severe injection site reactions, report them to the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk).

Frequently Asked Questions