Trulicity (dulaglutide) is a once-weekly injectable medication used to manage type 2 diabetes mellitus in adults. As a glucagon-like peptide-1 (GLP-1) receptor agonist, Trulicity works by mimicking a natural hormone that regulates blood sugar levels. When injected subcutaneously, it stimulates insulin release when glucose is elevated, slows gastric emptying to prevent post-meal blood sugar spikes, and suppresses glucagon secretion. Beyond glucose control, Trulicity affects appetite, body weight, and potentially cardiovascular health. Understanding what Trulicity does to your body helps you make informed decisions about your diabetes management and recognise both therapeutic benefits and potential side effects requiring medical attention.

What Is Trulicity and How Does It Work?

Trulicity (dulaglutide) is a prescription medicine used to treat type 2 diabetes mellitus in adults. It belongs to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, which work by mimicking the action of a naturally occurring hormone in your body called GLP-1. This hormone plays a crucial role in regulating blood sugar levels, particularly after eating.

When you inject Trulicity subcutaneously (under the skin) once weekly, it binds to GLP-1 receptors throughout your body, triggering several important physiological responses. The medication stimulates your pancreas to release insulin when blood glucose levels are elevated, helping to lower blood sugar in a glucose-dependent manner. This means the insulin-releasing effect diminishes as blood sugar normalises, which reduces the risk of hypoglycaemia (dangerously low blood sugar) compared to some other diabetes medications.

Trulicity also works by slowing gastric emptying, which means food moves more slowly from your stomach into your small intestine. This helps prevent rapid spikes in blood glucose after meals and contributes to feelings of fullness. Additionally, the medication suppresses the release of glucagon, a hormone that raises blood sugar levels by prompting the liver to release stored glucose.

Trulicity is started at a dose of 0.75 mg once weekly, which can be increased after at least 4 weeks to 1.5 mg, then potentially to 3.0 mg and 4.5 mg based on your response and tolerability. It should be injected into the abdomen, thigh or upper arm on the same day each week. If you miss a dose, take it as soon as possible if there are at least 3 days (72 hours) until your next scheduled dose.

The medication is not for use in type 1 diabetes or diabetic ketoacidosis and is not recommended in severe gastrointestinal disease such as gastroparesis. According to NICE guidance, GLP-1 receptor agonists like Trulicity are typically considered when other diabetes treatments haven't achieved adequate blood sugar control, particularly when weight is a concern or insulin is unsuitable.

Effects of Trulicity on Weight and Appetite

One of the notable effects of Trulicity on your body is its impact on body weight and appetite regulation. Many patients taking Trulicity experience weight loss, which can be particularly beneficial for people with type 2 diabetes, as excess weight often contributes to insulin resistance and poor glycaemic control.

The weight loss associated with Trulicity occurs through several mechanisms. By slowing gastric emptying, the medication helps you feel fuller for longer periods after eating, which naturally reduces overall calorie intake. Additionally, Trulicity acts on appetite centres in the brain, specifically areas that regulate hunger and satiety signals. This dual action means you may experience reduced appetite and decreased food cravings, making it easier to adhere to dietary recommendations.

Clinical trials have demonstrated that patients taking Trulicity typically lose between 2 to 6 kilograms over the course of treatment, with higher doses (3.0 mg and 4.5 mg) generally producing greater weight loss than lower doses. Individual results vary considerably. The weight loss tends to be gradual and occurs over several months rather than rapidly. It's important to note that Trulicity is not licensed as a weight-loss medication in the UK; weight reduction is considered a beneficial secondary effect of its glucose-lowering action.

Common gastrointestinal side effects such as nausea, vomiting, and diarrhoea—particularly when starting treatment—may also contribute to reduced food intake and weight loss. These effects are usually temporary and tend to improve as your body adjusts to the medication. If you experience persistent or severe gastrointestinal symptoms, contact your GP or diabetes specialist, as dose adjustments may be necessary. Seek urgent medical attention if you're unable to keep fluids down or show signs of dehydration, as this can affect kidney function.

There is also a small risk of gallbladder disease with GLP-1 receptor agonists like Trulicity. Contact your healthcare provider if you experience symptoms such as severe upper abdominal pain, particularly if it radiates to your back or shoulder, or if you notice yellowing of the skin or eyes.

Long-Term Effects of Trulicity on Your Body

Understanding the long-term effects of Trulicity is essential for anyone considering or currently using this medication. Beyond its immediate glucose-lowering properties, Trulicity has been studied extensively for its effects on various body systems over extended periods.

Cardiovascular effects have been evaluated in clinical research. The REWIND trial found that Trulicity reduced the risk of major adverse cardiovascular events, including heart attack, stroke, and cardiovascular death, in people with type 2 diabetes. However, it's important to note that in the UK, Trulicity is not specifically licensed for cardiovascular risk reduction, and its primary purpose remains blood glucose management.

Regarding pancreatic health, Trulicity stimulates insulin secretion in a glucose-dependent manner. However, there have been post-marketing reports of acute pancreatitis in patients taking GLP-1 receptor agonists. Whilst there is no definitive causal link established, you should be aware of symptoms such as severe, persistent abdominal pain radiating to the back. If you suspect pancreatitis, stop taking Trulicity immediately and seek urgent medical attention.

In animal studies, GLP-1 receptor agonists caused thyroid C-cell tumours in rodents. However, the clinical relevance to humans is unknown, and it's unclear whether these findings apply to people. The UK product information does not contraindicate Trulicity in patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2.

Kidney function should be monitored regularly in all patients with diabetes. If you experience symptoms such as reduced urination, swelling, or unexplained fatigue, contact your healthcare provider promptly for assessment. Severe vomiting or diarrhoea can lead to dehydration, which may affect kidney function, so maintaining adequate fluid intake is important.

There is also a potential risk of diabetic retinopathy complications, particularly in patients with pre-existing retinopathy who experience rapid improvement in blood glucose control. Regular eye examinations are recommended, and you should report any changes in vision to your healthcare provider promptly.

If you experience any suspected side effects from Trulicity, you can report them via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

How Trulicity Affects Blood Sugar Levels

The primary therapeutic effect of Trulicity is its ability to lower and stabilise blood glucose levels in people with type 2 diabetes. Understanding how this occurs helps patients appreciate the medication's role in their overall diabetes management strategy.

Trulicity works through a glucose-dependent mechanism, meaning its blood sugar-lowering effects are most pronounced when glucose levels are elevated. After you eat, carbohydrates are broken down into glucose, which enters your bloodstream. In response to rising blood sugar, Trulicity enhances insulin secretion from pancreatic beta cells, facilitating glucose uptake into muscle and fat cells. Simultaneously, it suppresses glucagon release, preventing the liver from releasing additional glucose into the bloodstream when it's not needed.

Clinical studies show that Trulicity typically reduces HbA1c (a measure of average blood glucose over 2-3 months) by approximately 0.8% to 1.5% (approximately 9-16 mmol/mol) when used as monotherapy or in combination with other diabetes medications. This reduction is clinically significant and helps reduce the risk of diabetes-related complications such as retinopathy, neuropathy, and nephropathy.

NICE guidance recommends an HbA1c target of 48 mmol/mol (6.5%) for most adults with type 2 diabetes if this can be achieved without causing problematic hypoglycaemia. A target of 53 mmol/mol (7.0%) may be more appropriate if you're taking medications that can cause hypoglycaemia, such as insulin or sulfonylureas. However, targets should be individualised based on your specific circumstances, preferences, and risk factors.

The once-weekly dosing of Trulicity provides consistent blood sugar control throughout the week, avoiding the peaks and troughs associated with some shorter-acting medications. This steady action helps reduce both fasting glucose levels (measured before eating) and postprandial glucose levels (measured after meals).

Hypoglycaemia risk with Trulicity alone is relatively low because insulin secretion decreases as blood glucose normalises. However, when combined with insulin or sulfonylureas, the risk increases, and doses of these medications may need to be reduced. Patients should be educated about hypoglycaemia symptoms—including trembling, sweating, confusion, and palpitations—and carry fast-acting carbohydrates. Regular blood glucose monitoring, as advised by your diabetes care team, helps ensure Trulicity is working effectively whilst maintaining safety. If you experience frequent hypoglycaemic episodes or persistently high readings, contact your GP for medication review and possible dose adjustment.

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