Can Wegovy replace other medications for weight loss in a treatment regimen?

In many cases, Wegovy can be used as the main weight loss medicine, especially when diet and exercise alone haven’t worked. However, switching or replacing other drugs should always be guided by a clinician, as some combinations may still be appropriate depending on health needs.

Wegovy as a first-choice option

Since its approval by NICE in 2023, Wegovy (semaglutide 2.4 mg weekly) has become the leading option for medical weight management in the UK. Clinical evidence from the STEP trials shows that it can achieve average weight loss of around 15% at 68 weeks, results that are greater than those seen with most other licensed weight-loss medicines. Because of this, many clinicians now view Wegovy as the preferred first-line pharmacological option when lifestyle measures alone are not enough.

Replacing older medicines

Before Wegovy, drugs like Orlistat, Saxenda, and Mysimba were the main pharmacological tools for weight loss. Orlistat works by reducing fat absorption, but its side effects and modest effectiveness (typically 5–7% weight loss) have limited its long-term use. Saxenda (liraglutide) and Mysimba (naltrexone/bupropion) can help, but their trial results — averaging 6–9% reductions — are generally smaller than those achieved with semaglutide. For many patients, switching to Wegovy offers stronger results and more manageable dosing (weekly instead of daily).

When switching makes sense

Switching to Wegovy may be considered if other medications have not provided sufficient results, or if side effects have made them difficult to continue. For example, people who struggled with Orlistat’s gastrointestinal effects, or found daily Saxenda injections inconvenient, may benefit from Wegovy’s weekly schedule and stronger appetite suppression. However, the transition must be done carefully, as dosing strategies and expectations differ between medicines.

When replacement is not straightforward

Despite its effectiveness, Wegovy does not automatically replace all other options. In some cases, other drugs may still be appropriate. Mysimba, for example, may be better suited for people whose main difficulty is managing cravings or emotional eating. Orlistat may still be considered where GLP-1 medicines are not tolerated or contraindicated. For people with type 2 diabetes, some medicines such as Trulicity or lower-dose semaglutide (Ozempic) may remain in use for blood sugar control, even if Wegovy is added for weight management.

NHS guidance on prescribing

The NHS pathway requires Wegovy to be prescribed within specialist weight-management services and alongside lifestyle support. This ensures that it is used appropriately and not simply as a replacement for all other options. NICE guidance notes that prescribing decisions should be individualised, considering health conditions, tolerability, and cost-effectiveness.

Risks of self-switching

It’s important to emphasise that patients should not attempt to replace medicines on their own. While Wegovy has strong evidence, combining or switching medicines without medical guidance can lead to dosing errors, side effects, or reduced effectiveness. Clinicians tailor treatment plans to ensure safety and sustained benefit.

The wider context

Wegovy is now the leading medicine for weight management, thanks to its strong trial evidence and NHS approval. It can replace older drugs in many cases, but it is not a one-size-fits-all solution. Some people may still benefit from alternatives, or from combination approaches overseen by a specialist. The key is careful, individualised prescribing that ensures the best results for each person.