What are the main differences between Wegovy and Trulicity?

Wegovy contains semaglutide at a higher dose and is licensed for weight management, while Trulicity (dulaglutide) is prescribed for type 2 diabetes. Weight changes with dulaglutide are usually modest compared with the significant reductions seen in trials of semaglutide for obesity.

Different active ingredients and purposes

The first key difference is that Wegovy and Trulicity contain different GLP-1 receptor agonists. Wegovy delivers semaglutide at doses up to 2.4 mg weekly, whereas Trulicity delivers dulaglutide, usually between 0.75 mg and 1.5 mg weekly in the UK. Although both act on the GLP-1 pathway to stimulate insulin release, slow stomach emptying, and reduce appetite, they were developed with different target populations in mind. Wegovy is specifically licensed for chronic weight management in adults who meet NICE criteria, while Trulicity is primarily licensed to help control blood glucose in people with type 2 diabetes.

Differences in effectiveness for weight management

The STEP clinical trial programme demonstrated that people using semaglutide 2.4 mg (Wegovy) lost on average around 15% of their body weight over 68 weeks. In contrast, dulaglutide trials for diabetes management generally show weight reductions of 2–3 kg, which is clinically useful but much smaller. In direct comparisons, semaglutide at higher doses consistently outperforms dulaglutide for weight outcomes. This is why NICE now recommends Wegovy within specialist services for people living with overweight or obesity, while dulaglutide is not positioned as a weight management treatment.

Impact on diabetes control

Trulicity is well established as a diabetes medicine. It lowers blood sugar levels, reduces HbA1c, and has been shown to reduce cardiovascular risk in people with type 2 diabetes. Wegovy can also improve blood sugar control, especially in people with diabetes, but its primary indication is weight reduction. In practice, someone with diabetes who also meets BMI criteria may be considered for semaglutide at weight-management doses, while Trulicity may be chosen when weight is less of a concern or when access to Wegovy is limited.

Administration and device design

Both medicines are given once weekly by subcutaneous injection, which is convenient compared to daily injections such as Saxenda. The difference lies in the device. Wegovy in the UK is supplied as a multi-dose FlexTouch pen containing four weekly doses. Trulicity, by contrast, comes as a series of single-use pens or prefilled syringes. Some patients prefer single-use devices as they reduce the need to change needles, while others like the multi-dose system for reducing packaging and remembering supply cycles.

Side-effect profiles

The most common side effects for both medicines are gastrointestinal, including nausea, vomiting, and diarrhoea. However, because Wegovy uses higher doses of semaglutide, these side effects may be more noticeable in the first few weeks of escalation. Trulicity, at lower doses of dulaglutide, tends to produce milder digestive issues for most users. That said, tolerability varies widely from person to person. Both drugs require careful dose escalation or clinical monitoring to manage these effects safely.

NHS access and guidance

In England, Scotland, and Wales, Wegovy is commissioned through specialist weight-management services under NICE TA875. Eligibility requires a BMI over 35 with at least one weight-related condition, or sometimes a BMI over 30 if other criteria are met. Trulicity, in contrast, is available in primary care as part of routine diabetes management. This difference in access reflects their different licensed uses. A person could be prescribed both in theory, though clinicians would weigh up the overlap in mechanisms and the person’s overall health goals.

Long-term outcomes and evidence

Large outcome studies also distinguish the two. Wegovy has been shown in the SELECT trial to reduce the risk of major cardiovascular events in people with overweight or obesity and existing heart disease. Trulicity has its own cardiovascular outcomes trial, REWIND, which showed it lowers cardiovascular risk in people with type 2 diabetes. These findings reinforce that both are beneficial but with different focus areas: Wegovy for weight reduction and associated risks, Trulicity for blood sugar control and diabetes complications.

What this means in practice

Although both medicines belong to the same GLP-1 family, Wegovy and Trulicity are not interchangeable. Wegovy is stronger for weight loss and is licensed specifically for that purpose, while Trulicity is targeted at type 2 diabetes management. They share some similarities in side effects and injection method, but their intended uses, dose strengths, and NHS access pathways are distinct. Understanding these differences helps patients and clinicians choose the option that fits best with individual health needs.