Trulicity (dulaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist widely prescribed in the UK for managing type 2 diabetes mellitus. Whilst effective at improving glycaemic control, many patients wonder: can Trulicity give you diarrhoea? The answer is yes—diarrhoea is a recognised and very common side effect of this medication, affecting more than 1 in 10 people. Understanding why this occurs, how to manage it, and when to seek medical advice is essential for anyone taking or considering Trulicity. This article provides evidence-based guidance aligned with UK clinical practice to help you navigate this common concern.

Can Trulicity Cause Diarrhoea?

Yes, Trulicity (dulaglutide) can cause diarrhoea as a recognised side effect. Trulicity is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus. It works by mimicking the action of the naturally occurring hormone GLP-1, which stimulates insulin secretion in response to food intake, suppresses glucagon release, and slows gastric emptying. This mechanism of action helps improve glycaemic control in people with type 2 diabetes.

The gastrointestinal effects of Trulicity, including diarrhoea, are directly related to its pharmacological action on the digestive system. By slowing gastric emptying and affecting gut motility, GLP-1 receptor agonists can alter normal bowel patterns. According to the UK Summary of Product Characteristics (SmPC), diarrhoea is classified as a 'very common' adverse reaction, meaning it affects more than 1 in 10 patients. This places diarrhoea among the most frequently reported side effects alongside nausea, vomiting, and abdominal pain.

It is important to understand that experiencing diarrhoea whilst taking Trulicity does not necessarily mean the medication is unsuitable for you. For many patients, gastrointestinal symptoms are most pronounced during the initial weeks of treatment and tend to diminish as the body adjusts to the medication. The severity can vary considerably between individuals, ranging from mild, occasional loose stools to more frequent episodes that may temporarily affect daily activities.

It's worth noting that Trulicity is not recommended for patients with severe gastrointestinal disease, including severe gastroparesis. Trulicity is available in four strengths in the UK: 0.75 mg, 1.5 mg, 3.0 mg and 4.5 mg, administered as a weekly injection.

How Common Is Diarrhoea with Trulicity?

Diarrhoea is classified as a 'very common' side effect of Trulicity in the UK product information. Clinical trials have shown that gastrointestinal side effects, including diarrhoea, are among the most prevalent adverse reactions associated with dulaglutide therapy. The frequency of diarrhoea appears to be dose-dependent, with higher rates generally observed at higher doses (1.5 mg, 3.0 mg and 4.5 mg weekly) compared to the lower 0.75 mg dose, though all strengths can cause this side effect.

According to European regulatory assessment data, diarrhoea typically emerges within the first few weeks of initiating Trulicity treatment. The majority of cases are mild to moderate in severity, with severe diarrhoea being relatively uncommon. Many patients who experience diarrhoea report that symptoms improve significantly after several weeks of treatment as physiological adaptation occurs. However, a smaller proportion of individuals may continue to experience intermittent episodes throughout their treatment course.

Several factors may influence an individual's likelihood of experiencing diarrhoea whilst taking Trulicity:

• Dose and titration – Starting at a lower dose and gradually increasing may help reduce gastrointestinal side effects

• Concurrent medications – Other drugs that can affect gut motility, such as metformin, may compound the effect

• Dietary factors – High-fat or high-fibre meals may potentially exacerbate symptoms in some people

• Individual sensitivity – Pre-existing gastrointestinal conditions may affect how you respond to the medication

It is worth noting that whilst diarrhoea is common, it does not affect the majority of patients, and many people tolerate Trulicity well without significant bowel disturbance. The benefits of improved glycaemic control often outweigh the temporary inconvenience of manageable gastrointestinal symptoms for most individuals.

Managing Diarrhoea While Taking Trulicity

Effective management of diarrhoea whilst taking Trulicity involves a combination of lifestyle modifications, dietary adjustments, and appropriate medical support. Most cases can be successfully managed without discontinuing treatment, allowing patients to continue benefiting from improved diabetes control.

Dietary and lifestyle strategies form the cornerstone of managing Trulicity-related diarrhoea:

• Stay well hydrated – Drink plenty of clear fluids (water, diluted squash, oral rehydration solutions) to replace lost fluids and electrolytes

• Modify your diet temporarily – Consider a bland diet with easily digestible foods such as bananas, rice, toast, and plain chicken

• Avoid trigger foods – Limit high-fat, spicy, or very high-fibre foods that may worsen symptoms

• Eat smaller, more frequent meals – This can reduce the burden on your digestive system

• Limit caffeine and alcohol – Both can exacerbate diarrhoea and contribute to dehydration

• Monitor timing – Some patients find that administering Trulicity on a specific day (when they can rest if needed) helps manage symptoms

From a clinical perspective, it is essential to maintain adequate hydration, particularly if diarrhoea is frequent or prolonged. Dehydration can affect kidney function and may require temporary adjustment of other medications. Never adjust your medication doses yourself – always consult your healthcare professional first. If you are taking Trulicity alongside sulfonylureas (such as gliclazide) or insulin, you may be at increased risk of hypoglycaemia, particularly during episodes of diarrhoea when food intake might be reduced.

Over-the-counter anti-diarrhoeal medications such as loperamide may provide symptomatic relief for occasional episodes, but should only be used after consulting with your GP or pharmacist. These medications are generally safe for short-term use but are not suitable if you have blood in your stool, high fever, or severe abdominal pain. Your healthcare team can provide personalised advice based on your individual circumstances and overall treatment plan.

If you experience persistent side effects, you should report them via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

When to Contact Your GP About Trulicity Side Effects

Whilst mild diarrhoea is a recognised and often self-limiting side effect of Trulicity, certain symptoms warrant prompt medical attention. Understanding when to seek professional advice is crucial for patient safety and optimal diabetes management.

Contact your GP or diabetes specialist nurse if you experience:

• Severe or persistent diarrhoea lasting more than 48 hours, particularly if accompanied by vomiting

• Signs of dehydration including excessive thirst, dark urine, dizziness, reduced urine output, or confusion

• Blood in your stools or black, tarry stools

• Abdominal pain that is constant or worsening, especially if localised to one area

• Fever (temperature above 38°C) accompanying diarrhoea, which may indicate infection

• Unexplained weight loss beyond what is expected from diabetes management

• Symptoms significantly affecting your quality of life or preventing you from maintaining adequate nutrition and hydration

• Right upper abdominal pain, jaundice (yellowing of skin/eyes), pale stools or dark urine – these may indicate gallbladder problems, which can occur with GLP-1 receptor agonists

If you develop severe, persistent upper abdominal pain (with or without vomiting), which may radiate to your back:

• This could indicate pancreatitis – stop taking Trulicity immediately and seek urgent medical attention

• Call NHS 111 (or NHS 24 in Scotland) for urgent advice if not immediately life-threatening

• Call 999 or attend A&E if symptoms are severe or you are very unwell

It is also important to contact your healthcare team for routine review if:

• Diarrhoea persists beyond the first several weeks of treatment without improvement

• You are struggling to maintain adequate nutrition due to gastrointestinal symptoms

• You are concerned about any aspect of your treatment or side effects

• You experience hypoglycaemia (low blood sugar) if you also take sulfonylureas or insulin, especially during periods of reduced food intake

Your GP may consider dose adjustment, temporary treatment interruption, or switching to an alternative diabetes medication if side effects are not adequately controlled. Never stop taking Trulicity abruptly without medical advice, as this may affect your blood glucose control. NICE guidance emphasises the importance of individualised diabetes care, and your healthcare team can work with you to find the most appropriate treatment regimen that balances efficacy with tolerability.

Frequently Asked Questions