Weight Loss Treatments Licensed in the UK

The Health Survey for England 2021 estimates that 63.8% of adults in England are overweight or obese, a 10.9% rise from data recorded since 1993*.

The National Institute for Health and Care Excellence (NICE) recommends that weight loss medication may be recommended as a treatment option for managing overweight and obesity ALONGSIDE a reduced-calorie diet and increased physical activity in adults.
Here is a brief overview of some of the most effective medications licensed to treat obesity in the UK, how they work and the evidence to support their use:

Licensed for people with a BMI of 30kg/m2 or more (or 27kg/m2 or more in the presence of one weight-related co-morbidity) when combined with a low-calorie diet and increased physical activity.
It works by reducing hunger, enhancing insulin secretion, reducing glucagon levels, and slowing gastric emptying, which helps regulate blood sugar levels and reduces appetite, leading to weight loss.

Clinical trials data show weight loss of up to 20% of body weight over 72 weeks (1.4 years).
In the SURMOUNT-4 trial, 89.5% of participants who took tirzepatide maintained at least 80% of their weight loss during the lead-in period, compared to 16.6% of those who took a placebo.

Mean change in body weight (%) from baseline to week 72

Licensed for people with a BMI of 30kg/m2 or more (or 27kg/m2 or more in the presence of one weight-related co-morbidity) when combined with a low-calorie diet and increased physical activity.
It works by inhibiting the absorption of approximately 30% of ingested dietary fat by inhibiting the enzyme lipase. This prevents fat absorption, allowing it to pass through the digestive system instead, aiding weight loss.

Initial weight loss: Clinical trials data shows weight loss of up to 5% of initial body weight typically occurs within 12 weeks of starting treatment when combined with a calorie-restricted, low fat diet.

Licensed for people with a BMI of 30kg/m2 or more (or 27kg/m2 or more in the presence of one weight-related co-morbidity) when combined with a low-calorie diet and increased physical activity.
Semaglutide is another GLP-1 receptor agonist that reduces hunger, enhances insulin secretion, suppresses glucagon release and slows stomach emptying, leading to weight loss by promoting reduced calorie intake.

In one study by Ghusn et al. (2022) including 1306 patients taking semaglutide 2.4 mg, weight loss of approximately 6% of initial body weight was achieved by week 12 and 12% was achieved by week 28.

Clinical trials data shows an average loss of 15-18% initial body weight is achieved over 68 weeks (1.3 years).

Mean change in body weight (%) from baseline to week 68

Licensed for people with a BMI of 30kg/m2 or more (or 27kg/m2 or more in the presence of one weight-related co-morbidity) when combined with a low-calorie diet and increased physical activity.
A GLP-1 receptor agonist that mimics the action of a natural hormone involved in appetite regulation. It slows gastric emptying, reduces hunger, and increases feelings of fullness, helping to reduce calorie intake and support weight loss.
SCALE diabetes trial: Patients in the liraglutide 3.0 mg, liraglutide 1.8 mg and placebo groups had a mean weight loss of 6.0% (6.4 kg), 4.7% (5.0 kg) and 2.0% (2.2 kg) respectively, at the end of 56 weeks. The weight loss with both liraglutide doses was significantly more than placebo (p < 0.001).

Overall, Clinical trials report 8-10% of body weight lost over 56 weeks (1 year).

Change from baseline in body weight (%) by time in trial 1 (0– 56 weeks)

*Baker, C. (2023). Obesity Statistics. House of Commons Library, 1(3336). https://commonslibrary.parliament.uk/research-briefings/sn03336/