An estimated 2.6million people already use weight-loss drugs to tackle stubborn fat.

Last month, a new pill form of Wegovy – the blockbuster slimming jab – was approved for use in the UK in what has been hailed as a game-changing moment for obesity treatment.

Take-up is expected to be huge, with studies suggesting people are twice as likely to opt for a tablet as an injection.

Yet for some, the results can be underwhelming, while others are reluctant to rely on medication at all.

Now experts say a little-known ingredient – known as Amarasate – could offer an alternative, naturally stimulating appetite-suppressing hormones and helping to boost weight loss.

Studies suggest people who take Amarasate, which is rich in bitter compounds, experience less food noise, eat smaller portions and feel fuller for longer.

Amarasate is derived from hops, the plant best known for giving beer its distinctive bitter taste. Researchers believe those same naturally occurring compounds may hold the key to curbing appetite.

'The bitterness is key,' says Dr Madusha Peiris, a neurogastroenterologist at Queen Mary University of London.

'Most people think taste happens only in the mouth, but the gut is also packed with specialised sensors that can detect compounds in the food we eat.

'When these sensors are activated, they trigger the release of hormones that influence hunger and fullness, helping to tell the brain when we've had enough to eat.

'The bitter compounds found in hops appear to be particularly effective at activating some of these pathways, including those linked to hormones such as GLP-1. These compounds are largely missing from modern diets, which is one reason researchers are so interested in them.'

So what is Amarasate – and how does it work?

First, it's important to understand how the body naturally regulates appetite.

While many nutrients are absorbed higher up in the digestive tract, others – particularly fibre – resist digestion until they reach the colon. This is significant because many of the cells responsible for producing appetite-suppressing hormones are concentrated in the lower gut.

'The more nutrients that reach the lower part of the gut, the more likely you are to feel full for longer,' says Dr Peiris.

'What seems to be a big problem for lots of people, especially those struggling to maintain a healthy weight, is food noise – repetitive thoughts about food that can drive snacking and overeating. That often stems from not producing enough of these appetite-suppressing hormones.'

This is where the bitter compounds in Amarasate – sold under the brand name Calocurb – come in.

The supplement, which costs around 75p per pill, is designed to deliver its bitter compounds much further down the digestive tract, near the colon, rather than releasing them in the stomach.

There, the compounds effectively trick the gut into thinking an intensely bitter food has arrived, activating receptors that trigger the release of satiety hormones, including GLP-1, peptide YY (PYY) and cholecystokinin (CCK).

These are the same hormones released after eating a diverse, fibre-rich meal. But, as Dr Peiris explains, modern diets often fail to stimulate this response.

'Highly processed foods, which tend to contain a lot of free sugars and require very little chewing, don't activate these fullness signals as effectively,' she says. 'As a result, we start releasing satiety hormones much later.'

'Digestion then happens relatively quickly, with food broken down and absorbed before it can reach many of these key receptors further down the digestive tract.'

Weight loss drugs work on some of the same hormonal pathways, but in a much more potent way, flooding the body with synthetic GLP-1 at levels far above those produced naturally.

Research suggests Amarasate may help stimulate the body's own appetite-regulating systems. A 2022 study published in the American Journal of Clinical Nutrition found that it reduced the number of calories men consumed at mealtimes by almost 20 per cent, while significantly increasing levels of key satiety hormones.

A more recent study involving women produced similar findings, with participants reporting up to a 40 per cent reduction in food cravings.

Another trial, published in Nutrition Journal, followed 200 overweight adults and found those given a bitter hops extract daily had significantly less visceral fat after eight weeks than those receiving a placebo.

Visceral fat is considered particularly dangerous because it accumulates deep inside the abdomen, surrounding organs such as the liver and pancreas and increasing the risk of conditions including heart disease and type 2 diabetes.

After 12 weeks, participants taking the hops extract had lost around seven times more visceral fat than those in the placebo group, while also reducing their overall body-fat levels.

However, experts caution that the evidence remains limited and there is not yet enough research to suggest supplements such as Amarasate could replace prescription weight loss drugs, particularly for patients with obesity-related conditions such as diabetes or sleep apnoea.

Dr Peiris believes the findings nevertheless highlight the importance of naturally stimulating the gut's appetite-control systems through diet.

'As a gut scientist who studies nutrient-sensing mechanisms, it's encouraging to see human studies showing changes in appetite and appetite-regulating hormones,' she says.

'But bitter, fibre-rich foods are likely to have a much greater impact because they stimulate these receptors while also nourishing the gut.

'Humans fundamentally know the kinds of foods they should be eating, but in modern society it's becoming increasingly difficult to eat a diverse range of fruits and vegetables.

'It's that combination of colourful, fibre-rich foods that really helps to support gut health and maximise the release of these satiety hormones.'

This comes amid growing interest in natural ways to activate the same biological pathways targeted by blockbuster weight loss drugs.

Earlier this year, experts told the Daily Mail that psyllium husk – a fibre supplement costing as little as 7p per serving – could help 'turbo-charge' the effects of Wegovy and Mounjaro by increasing feelings of fullness, reducing cholesterol levels and potentially helping patients maintain their weight loss after coming off the drugs.

Researchers say both psyllium husk and Amarasate appear to work by stimulating the body's own appetite-control mechanisms, albeit in different ways.

However experts stress that neither supplement is a replacement for medical treatment.