WHO scientists endorse weight loss drugs for controlling obesity: What does it mean for therapies?

Dr Francesca Celletti and Dr Francesco Branca from WHO’s department of Nutrition and Food Safety and Dr Jeremy Farrar, chief scientist at WHO  wrote, “Efforts to slow the obesity pandemic have focused almost exclusively on policies that help embed healthy diets and regular physical activity … Although there is good evidence on the effectiveness of such policies …, it is time to recognise that multi-sectoral efforts to influence behaviours … have so far failed to treat obesity or turn the tide on the obesity pandemic. In this context, the new class of GLP-1 RAs have the potential to be transformative.”

Why is this significant?

This endorsement comes at a time when patents for the popular drug semaglutide are set to expire over the next couple of years in several countries, including India and Brazil. In India, several manufacturers of generic compounds have already started bioequivalence trials for their products so that they can be ready for use once the patents expire. Bioequivalence trials are conducted to ensure that generic versions of the products are as safe and effective as the branded versions. Several new medicines in this category are also under trial globally.

Globally, one in eight people were living with obesity in 2022. There were 890 million adults and 160 million adolescents living with obesity in 2022. The prevalence of obesity has doubled in adults since 1990 and quadrupled in adolescents, according to the WHO. In India, there were 44 million women and 26 million men living with obesity in 2022. In the three decades between 1990 to 2022, the prevalence of obesity in women increased 8.6 percentage points and prevalence in men increased 4.9 percentage points. There has also been a significant increase in childhood obesity in the three decades. While 0.2 million boys and 0.2 million girls were obese in 1990, 7.3 million boys and 5.2 million girls were obese in 2022. WHO scientists say that global costs associated with obesity are likely to reach $3 trillion by 2030. In countries with 30 per cent prevalence of obesity, it could absorb up to 18 per cent of the national health expenditure. Scientists also argue that obesity adds to mortality — there were five million obesity-related deaths from non-communicable diseases in 2019. This accounted for 12 per cent of all deaths from non-communicable diseases worldwide.

Will WHO also release guidelines for use?

The WHO is currently in the process of drafting guidelines for the use of GLP-1 receptor agonists in adults with obesity to provide clarity on “clinical indications, application and programmatic considerations globally.” These guidelines are likely to be published in July 2025.

What are popular diabetes cum weight loss drugs?

Novo Nordisk’s Ozempic, originally approved in 2017 for type 2 diabetes, gained immense popularity as doctors prescribed it off-label for obesity, sparking a social media frenzy and supply shortages. In 2021, the USFDA approved Wegovy, another semaglutide-based drug from Novo Nordisk, marking the first chronic weight management treatment in a decade. Meanwhile, Eli Lilly’s Zepbound, approved in 2023, and its diabetes drug Mounjaro, also used off-label for weight loss, have joined the ranks of high-demand therapies for obesity care.

WHO raised red flags too

While the new therapies have shown to reduce body weight between 10 and 25 per cent, experts have said it should not be used by all as there are severe side effects such as gastroparesis (stomach paralysis), pancreatitis (inflamed pancreas) and thyroid cancer. Another important consideration is that a person is likely to gain weight when they stop using the medicine and it is yet to be seen whether the drug can keep working over several years.

Given the high costs of the products, the high demand and the production and supply challenges, scientists have also raised the issue of “counterfeit products” and grey markets. However, the medicines are likely to become more readily available as they get off patents.