Trulicity (dulaglutide) is a once-weekly injectable medication widely used to improve blood glucose control in adults with type 2 diabetes. As a glucagon-like peptide-1 (GLP-1) receptor agonist, it works by stimulating insulin release, suppressing glucagon, and slowing gastric emptying. Trulicity is typically prescribed when diet, exercise, and oral medications such as metformin have not achieved adequate glycaemic control. NICE guidance recommends considering GLP-1 receptor agonists like Trulicity particularly for patients where weight loss would be beneficial or where insulin therapy poses practical challenges. This article explores how Trulicity works, who can use it, dosing guidance, and important safety considerations for UK patients.

What Is Trulicity and How Does It Work for Type 2 Diabetes?

Trulicity (dulaglutide) is a once-weekly injectable medication used to improve blood glucose control in adults with type 2 diabetes mellitus. It belongs to a class of medicines called glucagon-like peptide-1 (GLP-1) receptor agonists, which mimic the action of a naturally occurring hormone that helps regulate blood sugar levels after eating.

The mechanism of action of Trulicity involves several complementary pathways. When administered, dulaglutide binds to GLP-1 receptors on pancreatic beta cells, stimulating insulin secretion in a glucose-dependent manner. This means insulin is released only when blood glucose levels are elevated, which reduces the risk of hypoglycaemia compared to some other diabetes medications. Simultaneously, Trulicity suppresses glucagon release from pancreatic alpha cells, thereby reducing hepatic glucose production when it is not needed.

Beyond its effects on insulin and glucagon, Trulicity also slows gastric emptying, which helps moderate the post-meal rise in blood glucose. Many patients experience a degree of appetite reduction, which may contribute to weight loss—a beneficial effect for many individuals with type 2 diabetes who are overweight or obese.

Trulicity is typically prescribed when diet, exercise, and oral antidiabetic medications (such as metformin) have not achieved adequate glycaemic control. According to NICE guidance NG28 (Type 2 diabetes in adults: management), GLP-1 receptor agonists like Trulicity may be considered as part of dual or triple therapy regimens, particularly in patients where weight loss would be beneficial or where insulin therapy is being considered but poses practical challenges. The once-weekly dosing schedule may be more convenient for some patients, though adherence benefits vary between individuals.

UK references: Electronic Medicines Compendium (emc) Summary of Product Characteristics (SmPC) for Trulicity; NICE NG28; NHS medicines A–Z: Dulaglutide (Trulicity).

Who Can Use Trulicity for Type 2 Diabetes Management?

Trulicity is licensed for use in adults aged 18 years and over with type 2 diabetes mellitus. It is not approved for the treatment of type 1 diabetes or diabetic ketoacidosis. The medication can be used alone (monotherapy) in patients who cannot tolerate metformin, or more commonly as part of combination therapy with other glucose-lowering medicines including metformin, sulfonylureas, sodium-glucose co-transporter-2 (SGLT2) inhibitors, or basal insulin.

NICE NG28 recommends that GLP-1 receptor agonists such as Trulicity should be considered for patients with a body mass index (BMI) of 35 kg/m² or higher (or 32.5 kg/m² or higher for people of South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean family origin), or for those in whom insulin therapy would have significant occupational implications or weight gain would cause significant clinical problems. Trulicity may also be appropriate for patients with inadequate glycaemic control (HbA1c typically ≥58 mmol/mol or 7.5%) despite optimised oral therapy. Treatment should be reviewed at around 6 months to assess clinical benefit and tolerability, in line with NICE guidance and local pathways.

However, certain individuals require special consideration. Trulicity should be used with caution in patients with a personal or family history of medullary thyroid carcinoma or in those with multiple endocrine neoplasia syndrome type 2 (MEN 2). Although GLP-1 receptor agonists have been associated with thyroid C-cell tumours in rodent studies, the clinical relevance to humans is unknown. Patients should be counselled to seek medical review if they develop symptoms such as a neck lump, difficulty swallowing, or persistent hoarseness.

Trulicity should also be used with caution in patients with a history of pancreatitis or severe gastrointestinal disease. No dose adjustment is needed in renal impairment, including severe impairment (eGFR <30 mL/min/1.73 m²); however, there is very limited experience in end-stage renal disease, so particular caution and monitoring of hydration and renal function are advised if significant gastrointestinal adverse effects occur.

Pregnancy and breastfeeding: Trulicity should be avoided during pregnancy. Women of childbearing potential should discontinue Trulicity at least one month before a planned pregnancy due to its long half-life. Trulicity should not be used during breastfeeding. Patients should discuss their full medical history and any plans for pregnancy with their healthcare provider to determine suitability.

UK references: emc SmPC for Trulicity (dulaglutide); NICE NG28; BNF dulaglutide monograph.

How to Use Trulicity: Dosage and Administration

Trulicity is supplied as a pre-filled, single-use pen designed for subcutaneous injection, making administration straightforward for most patients. The medication is injected once weekly, on the same day each week, at any time of day and without regard to meals. This flexible dosing schedule can help patients integrate treatment into their routine more easily. If you need to change your injection day, ensure there are at least 3 days (72 hours) since your last dose.

The recommended starting dose is 0.75 mg once weekly. Based on individual glycaemic response and tolerability, the dose may be increased in increments to 1.5 mg, 3 mg, or 4.5 mg once weekly. Dose escalation should be gradual, typically at intervals of at least four weeks, to minimise gastrointestinal side effects. The maximum licensed dose is 4.5 mg once weekly. Healthcare professionals will determine the appropriate dose based on HbA1c targets, tolerability, and overall treatment goals.

Trulicity is for subcutaneous use only (not intravenous or intramuscular). It should be injected into the abdomen, thigh, or upper arm. Patients should rotate injection sites with each dose to reduce the risk of local injection reactions. If you are also using insulin, give Trulicity and insulin as separate injections at different sites. The pen does not require reconstitution or dose measurement—patients simply remove the cap and press the pen against the skin until they hear a click, then hold for approximately 5–10 seconds.

Important administration guidance includes:

• Store unused pens in the refrigerator (2–8°C); do not freeze

• A single pen may be kept at room temperature (up to 30°C) for up to 14 days if needed

• Inspect the solution before use—it should be clear and colourless to slightly yellow

• If a dose is missed, administer as soon as possible if there are at least 3 days (72 hours) until the next scheduled dose; otherwise, skip the missed dose

• Never share pens with another person, even if the needle is changed

• Dispose of used pens in an approved sharps bin; your pharmacy or diabetes team can advise on safe disposal

• Patients should receive proper training on injection technique from their diabetes care team

UK references: emc SmPC for Trulicity (dulaglutide); Trulicity Patient Information Leaflet (PIL); NHS medicines A–Z: Dulaglutide – how to take it.

Common Side Effects and Safety Considerations

Like all medications, Trulicity can cause side effects, although not everyone experiences them. The most frequently reported adverse effects are gastrointestinal in nature and include nausea, diarrhoea, vomiting, abdominal pain, and decreased appetite. These symptoms are usually mild to moderate, tend to occur early in treatment, and often diminish over time as the body adjusts to the medication. Starting at a lower dose and increasing gradually can help minimise these effects.

Hypoglycaemia (low blood sugar) is uncommon when Trulicity is used alone or with metformin, but the risk increases when it is combined with sulfonylureas or insulin. Patients using these combinations may require dose adjustments of their other diabetes medications; your healthcare team will review this regularly. Symptoms of hypoglycaemia include trembling, sweating, confusion, palpitations, and hunger. Patients should be educated to recognise these signs and carry a fast-acting source of glucose.

More serious but rare adverse effects include acute pancreatitis. Patients should seek immediate medical attention if they experience persistent, severe abdominal pain that may radiate to the back, with or without vomiting. Trulicity should be discontinued if pancreatitis is suspected. There have also been post-marketing reports of acute kidney injury, particularly in patients experiencing severe gastrointestinal side effects leading to dehydration.

Gallbladder problems (including gallstones and inflammation of the gallbladder) have been reported with GLP-1 receptor agonists. Seek medical help if you develop right upper abdominal pain, fever, or jaundice (yellowing of the skin or eyes).

Injection site reactions (redness, itching, or swelling) may occur but are generally mild. Allergic reactions, including rash and itching, have been reported. Severe allergic reactions (anaphylaxis) are rare but require urgent medical attention; seek help immediately if you experience breathing difficulty, facial swelling, or severe rash.

When to contact your GP or diabetes team:

• Persistent or severe abdominal pain

• Right upper abdominal pain, fever, or jaundice

• Signs of dehydration (reduced urination, dizziness, dry mouth)

• Recurrent hypoglycaemia

• Unexplained weight loss or persistent vomiting

• Symptoms of thyroid nodules (neck lump, difficulty swallowing, persistent hoarseness)

• Signs of severe allergic reaction (breathing difficulty, facial swelling)

Regular monitoring of HbA1c, renal function, and body weight is recommended as part of ongoing diabetes care. Patients should attend scheduled reviews with their healthcare team to assess treatment effectiveness and tolerability, ensuring Trulicity remains an appropriate component of their diabetes management plan.

Reporting side effects: If you experience any side effects, talk to your doctor, pharmacist, or diabetes nurse. You can also report suspected side effects via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or by downloading the Yellow Card app. Reporting helps provide ongoing safety information about this medicine.

UK references: emc SmPC for Trulicity (dulaglutide); NHS medicines A–Z: Dulaglutide – side effects; MHRA Yellow Card scheme.

Frequently Asked Questions