SCIENTISTS have created a new weight loss drug that could potentially offer stronger and safer results than today’s popular options.
Most existing weight loss drugs act on one, two, or sometimes three hormones that influence glucose metabolism and appetite.
But researchers at Tufts University have now uncovered a fourth hormone that could be added to the mix.
While their new drug is yet to be trialled in studies, it could achieve up to 30 per cent weight loss.
An estimated 1.5 million people in the UK are currently using weight loss jabs , such as Mounjaro or Wegovy.
But despite their effectiveness, they do come with some drawbacks.
Like all medications , they can trigger uncomfortable side effects like nausea, which can make it difficult to stay on top of treatment, as well as osteoporosis and muscle loss.
Emerging studies have also suggested their effects may not last after patients stop using them.
The Tufts research team, led by Krishna Kumar, Robinson Professor of Chemistry, designed a new, next-generation compound, with hopes it could be more effective with fewer side effects.
“Obesity is linked to over 180 different disease conditions, including cancer , cardiovascular disease, osteoarthritis, liver disease, and type 2 diabetes , and affects over 650 million people worldwide,” said Kumar.
“What drives us is the idea that we can design a single drug to treat obesity and simultaneously mitigate the risk of developing a long list of health problems plaguing society.”
So how does the new drug work?
Many weight loss drugs, like Ozempic , mimic glucagon-like peptide-1 (GLP-1) – a natural hormone produced in the body that regulates blood sugar and appetite.
But according to Kumar, this isn’t the perfect strategy for weight loss.
“The biggest problem with GLP-1 drugs is that they have to be injected once a week, and they can induce a very strong feeling of nausea.
“As much as 40 per cent of people using these drugs give up after the first month.”
Other hormones that assist weight loss have been incorporated into treatments to make them more tolerable.
For example, a second hormone released after eating is glucose-dependent insulinotropic peptide (GIP), which looks a lot like GLP-1 and also makes people feel full after a meal.
But rather than administering two drugs, researchers have created one peptide that incorporates structural elements of both – what we know as Mounjaro – with the added benefit of significantly reducing nausea.
“And then there is a third hormone, glucagon,” said Kumar.
“Paradoxically, it actually increases blood glucose, but at the same time increases the expenditure of energy in cells of the body, raises body temperature, and suppresses appetite.”
Drug developers have also created a drug that incorporates elements of all three hormones, known as retatrudide, which is currently in clinical trials but has shown potential for greater weight loss (up to 24 per cent) than GLP-1 drugs (6-15 per cent).
But Kumar’s team have been going for a fourth hormone target.
“The goal that people are trying to shoot for is bariatric surgery ,” he said.
The surgical procedure significantly reduces the size of the stomach, and can achieve long-lasting weight loss up to 30 per cent.
Kumar added: “For individuals with persistent obesity and potential deadly associated conditions, it becomes a necessary but invasive treatment.”
With their drug redesign, Tufts chemist are aiming to match bariatric surgery’s 30 per cent weight loss outcome – without the invasiveness or surgical risks.
“There is one more hormone we wanted to bring in to complete a weight control quartet,” said Tristan Dinsmore, a graduate student in the Kumar lab and the lead author of the study.
“It’s called peptide YY (PYY). This molecule is also secreted by the gut after we eat a meal, and its job is to reduce appetite and slow the process of emptying food from the stomach, but via different mechanisms than either GLP-1 or GIP.
“It may also be involved in directly ‘burning off’ fat.”
“By hitting four different hormone receptors at the same time, we hope to deliver more consistent and lasting results,” said Martin Beinborn, visiting scholar and study co-author.
The researchers also believe the drug may help preserve muscle and bone mass, and early findings suggest it could also delay or reduce weight regain after discontinuation.
For now the drug remains experimental and will require years of testing before it becomes publicly available.
Everything you need to know about fat jabs
Weight loss jabs are all the rage as studies and patient stories reveal they help people shed flab at almost unbelievable rates, as well as appearing to reduce the risk of serious diseases.
Wegovy – a modified version of type 2 diabetes drug Ozempic – and Mounjaro are the leading weight loss injections used in the UK.
Wegovy, real name semaglutide, has been used on the NHS for years while Mounjaro (tirzepatide) is a newer and more powerful addition to the market.
Mounjaro accounts for most private prescriptions for weight loss and is set to join Wegovy as an NHS staple this year.
How do they work?
The jabs work by suppressing your appetite, making you eat less so your body burns fat for energy instead and you lose weight.
They do this my mimicking a hormone called GLP-1, which signals to the brain when the stomach is full, so the drugs are officially called GLP-1 receptor agonists.
They slow down digestion and increase insulin production, lowering blood sugar, which is why they were first developed to treat type 2 diabetes in which patients’ sugar levels are too high.
Can I get them?
NHS prescriptions of weight loss drugs, mainly Wegovy and an older version called Saxenda (chemical name liraglutide), are controlled through specialist weight loss clinics.
Typically a patient will have to have a body mass index (BMI) of 30 or higher, classifying them as medically obese, and also have a weight-related health condition such as high blood pressure.
GPs generally do not prescribe the drugs for weight loss.
Private prescribers offer the jabs, most commonly Mounjaro, to anyone who is obese (BMI of 30+) or overweight (BMI 25-30) with a weight-related health risk.
Private pharmacies have been rapped for handing them out too easily and video calls or face-to-face appointments are now mandatory to check a patient is being truthful about their size and health.
Are there any risks?
Yes – side effects are common but most are relatively mild.
Around half of people taking the drug experience gut issues, including sickness, bloating, acid reflux, constipation and diarrhoea.
Dr Sarah Jarvis, GP and clinical consultant at patient.info, said: “One of the more uncommon side effects is severe acute pancreatitis, which is extremely painful and happens to one in 500 people.”
Other uncommon side effects include altered taste, kidney problems, allergic reactions, gallbladder problems and hypoglycemia.
Evidence has so far been inconclusive about whether the injections are damaging to patients’ mental health.
Figures obtained by The Sun show that, up to January 2025, 85 patient deaths in the UK were suspected to be linked to the medicines.
