In my 30 years as an obesity researcher, I’ve seen all kinds of “wonder cures” come and go. Some were withdrawn due to serious side-effects; most have had only a relatively modest effect on people’s body mass.
But now a new generation of medications has arrived, based on a better understanding of the biological underpinnings of obesity. While previous pharmaceutical treatments resulted in weight loss of 5-10%, clinical trials of this new wave of drugs are reporting initial weight loss of 15-20%. They work by suppressing appetite and slowing down digestion so we feel full for longer. One of these medications – semaglutide, sold under the brand name Wegovy – will soon be available in UK chemists in the form of a weekly, self-administered injection.
Social media users who have tried semaglutide (which is sold in the US under the brand name Ozempic) rave that the drug instantly changed their relationship with food – “flicking a switch” to turn off their hunger and cravings. Elon Musk has used it, and rumours abound about that other celebrities have too. It sounds revolutionary, right? Potentially, yes – but only up to a point.
These drugs are so effective because they address one of the many complex causes of obesity. When we eat, our bodies usually release “satiety hormones” to make us feel full. But in people living with obesity this doesn’t always happen, which can result in uncontrolled hunger and a heightened responsiveness to food. Prolonged restriction of food – also known as dieting, something most people living with obesity will face pressure to do – can further weaken that satiety hormone response. Wegovy contains the satiety hormone GLP1, which steps in where the body’s hormones may have failed, boosting sensations of fullness, suppressing reward-driven eating and increasing feelings of control.
However, caution is needed. Semaglutide side-effects can include nausea, bloating, diarrhoea and wind, and close medical supervision is needed as the dose is increased over the first four weeks.
While there is no doubt that these drugs are an important tool in the management of obesity, they are only that – one tool. The drug fulfils a biological function, but it doesn’t provide mental health support or treatment for an eating disorder. Drastic weight loss can have unpredictable effects on mental health: one study found that almost one in five people who receive bariatric surgery later experience depression.
Some people living with obesity have used food as a coping mechanism to deal with stress, or underlying mental health issues – they will need support once that coping mechanism is removed. Weight-loss treatments should be implemented as part of a much wider support programme that includes advice on nutrition and eating behaviour, psychological support and supported physical activity.
The National Institute for Health and Care Excellence has released draft guidance recommending that Wegovy become available on the NHS for those with a BMI over 35, but for now the drug will only be sold through chemists such as Asda, Superdrug and Boots. You’ll still need a prescription, but these chemists won’t necessarily be able to ensure that the drug is used as part of a programme of wider support.
Obesity is complex, and is becoming widely recognised as a lifelong, chronic, relapsing disease. We can get better at management, but we haven’t found a cure, Wegovy included.
Healthcare practitioners need training in obesity management, access to a range of clinical tools and options to work with, and an evidence base to help inform treatment plans to meet individuals’ need. We also require considerable investment in specialised weight management services within the communities which need them most.
And while most people appropriately prescribed the drug will experience some benefits, Wegovy will not work for everyone. The drivers of obesity are diverse, and no drug addresses situational and psychology factors. Structural health inequalities, poverty, mental health issues and the impact of trauma – all shown to drive weight gain – will never be fixed by a jab.
