GLP-1 and GLP-1/GIP products currently licensed for weight loss in the UK—Saxenda (liraglutide), Wegovy (semaglutide), and Mounjaro (tirzepatide)—are licensed by the Medicines and Healthcare products Regulatory Agency for patients who (i) have obesity (body mass index [BMI] ≥ 30 kg/m2) or (ii) have a BMI in the overweight range (BMI ≥ 27 kg/m2) plus weight-related comorbidities, such as cardiovascular disease [12]. This evidence concerns the gene GCG and obesity due to melanocortin 4 receptor deficiency.