TL:DR – Semaglutide is known to US celebrities as the “skinny jab” and has apparently been the subject of a weight-loss craze. It has now been approved in the UK for weight-loss in the clinically obese.
Semaglutide is a pharmaceutical that can help control the symptoms of Type 2 diabetes for which it was first used. The nickname, the “skinny jab” comes from the drug’s activity as an appetite suppressant used in helping overweight people and the obese reduce their body weight. It is sold under the brand names Ozempic, Wegovy and Rybelsus and was originally developed by Novo Nordisk in 2012. Clinical trials of the weekly injected drug were completed in 2017.
In March 2023, the UK’s National Institute for Health and Care Excellence (NICE) recommended provision of the drug to specialist treatment centres under the National Health Service (NHS).
The main mode of action of the drug, according to the NICE website, is to activate the GLP-1 (glucagon-like peptide-1) receptor, which increases activity in the pancreas to boost insulin secretion into the blood. Insulin is the hormone that raises the concentration of glucose in the bloodstream.
Semaglutide also suppresses glucagon secretion. Glucagon is insulin’s counterpart hormone produced by the pancreas. It raises the concentration of glucose and fatty acids in the bloodstream.
The drug slows the rate at which the stomach empties its contents into the next portion of the gastrointestinal tract, the duodenum (the first section of the small intestine). This sustains a person’s feeling of fullness, or satiety, for longer and so can reduce the frequency with which they feel they need to eat.
The NICE website lists several cautions, side-effects, and contraindications for this expensive drug. Nevertheless, in February 2022 it put a case based on both risk-benefit and cost-benefit analyses for its use under the NHS for people with at least one weight-related condition and an exceptionally high body-mass index. In March 2022, NICE recommended provision of the drug for a sub-group of obese patients who might see a ten percent weight reduction if the drug is used in parallel with improvements in diet (less processed food and a reduction in calorie intake, fundamentally) and increased activity and exercise.