How does Wegovy compare to non-prescription weight loss methods like over-the-counter supplements?

Wegovy has been tested in large clinical trials and shown to deliver sustained, clinically meaningful weight loss. Over-the-counter supplements rarely have robust evidence and typically produce little to no lasting effect, so the gap in proven effectiveness is significant.

What makes Wegovy different

Wegovy contains semaglutide, a GLP-1 receptor agonist that has been through rigorous clinical trials involving thousands of participants worldwide. The STEP programme of studies showed that people using semaglutide 2.4 mg weekly lost an average of 15% of their body weight over 68 weeks when combined with diet and exercise. These results were published in leading medical journals such as The New England Journal of Medicine and underpin NICE’s decision to recommend Wegovy within NHS specialist services.

The evidence gap for supplements

By contrast, most over-the-counter weight-loss supplements — whether marketed as fat burners, appetite suppressants, or metabolism boosters — lack large-scale, peer-reviewed evidence. Independent reviews consistently find that their effects are minimal or inconsistent. Even when small studies suggest a modest benefit, the results are rarely replicated in larger trials. Unlike prescription medicines, supplements are not held to the same regulatory standards for demonstrating effectiveness before they are sold.

Sustainability of results

One of the key differences lies in long-term outcomes. Wegovy has shown in the STEP-5 trial that weight loss can be sustained over two years with ongoing treatment. Over-the-counter supplements, on the other hand, usually fail to demonstrate lasting effects once initial enthusiasm or placebo influence wears off. This gap is why healthcare professionals view prescription medicines like Wegovy as evidence-based tools, while supplements are often seen as unproven and unreliable.

Safety considerations

Another important distinction is safety. Prescription medicines like Wegovy undergo extensive testing not only for effectiveness but also for safety, with side effects and rare risks carefully monitored in trials and in real-world use. For supplements, safety oversight is weaker. Some products have been found to contain undeclared or unsafe ingredients, and others interact with prescription medicines in unpredictable ways. Regulatory bodies like the MHRA and FDA have issued repeated warnings about such risks.

Cost versus value

On the surface, supplements may appear cheaper and more accessible than prescription treatments. However, without proven effectiveness, repeated spending on these products often leads to disappointment and wasted money. Wegovy is more expensive, but its clinical benefits are well documented, and in the UK it can be accessed through NHS services for those who meet eligibility criteria. This makes it a more cost-effective option when long-term health outcomes are taken into account.

NHS guidance

NICE does not recommend supplements for weight management due to the lack of robust evidence. Instead, it prioritises treatments with strong clinical backing, like Wegovy, which has demonstrated both significant weight reduction and improvements in cardiovascular outcomes through the SELECT trial. This reinforces the gap between prescription therapies and non-prescription products.

The full perspective

Wegovy stands apart from over-the-counter weight-loss supplements because it is supported by large, high-quality trials and formal approval from regulators. Supplements are widely available but rarely supported by strong evidence, and their benefits are usually small or short-lived. For people seeking meaningful, sustained weight loss, the difference in proven effectiveness between the two is clear — Wegovy offers real, measurable results, while supplements remain largely unproven.