Natural GLP-1: can you raise your own GLP-1 without medication?

On a single day in August 2025, the Advertising Standards Authority banned adverts from three supplement brands. One sold berberine as a "natural GLP-1 secretion enhancer", another a fibre drink billed as "nature's GLP-1", the third a supplement said to "rapidly boost GLP-1 production". The watchdog's reasoning was the same each time: talk of natural GLP-1 on a food supplement invites a comparison with prescription weight loss injections, and no supplement is entitled to make it.

The rulings settle what can be advertised. They leave the underlying question open, and it is a fair one: can food, or something from a health shop, deliver a little of what the new obesity medicines do? The honest answer comes in two halves. Yes, the body makes its own GLP-1, and we know what encourages it: protein, fibre and a few habits at the table. No, the effect looks nothing like that of a medicine, and nothing sold off the shelf can claim otherwise.

A hormone that lasts two minutes

GLP-1, short for glucagon-like peptide-1, is made by cells in the lining of the gut called L cells, most of them in the last stretch of the small intestine and in the colon. They release it within minutes of food arriving.

It carries three messages. To the pancreas, it asks for more insulin when blood sugar rises. To the stomach, it says slow down, which is why a meal can seem to sit with you for a while. To the brain, it signals that you have had enough.

Then it vanishes. An enzyme called DPP-4 breaks it down in one to two minutes. The whole gap between the hormone and the medicines lies there: semaglutide was engineered to resist that enzyme and stay active for about a week.

What people mean by natural GLP-1

Depending on who is using the phrase, it refers to three things that have little to do with one another.

One point of law explains a good deal of what follows. Neither the Great Britain register of nutrition and health claims nor its EU counterpart contains an authorised claim about GLP-1. On a tub or a pouch, those letters tell you what the manufacturer would like you to think. They say nothing about what the product has been shown to do.

On the plate, what stimulates GLP-1

L cells respond to whatever passes them, and some nutrients prompt them more than others.

Protein comes first. Its amino acids act directly on these cells, and a meal that contains protein triggers a clearer release than a meal of the same calories made mostly of carbohydrate. Eggs, fish, chicken, dairy, beans and lentils all count, and the source matters less than having some at every meal.

Fibre comes next, by two routes. Viscous fibres, the kind found in psyllium husk, konjac or carob gum, form a gel that slows the emptying of the stomach. Fermentable fibres, found in oats, pulses, leeks, onions and artichokes, travel on to the colon, where they feed the gut bacteria.

The unsaturated fats in olive oil, avocado and nuts also activate receptors on L cells, though the evidence is thinner. As for the polyphenols in green tea, cocoa or hibiscus, the data are still preliminary.

A rule of composition serves better than a list of superfoods: a protein, a vegetable or a pulse, a good-quality fat. Order matters as well. Several studies suggest that starting with the vegetables and protein, and leaving the starchy food until last, softens the rise in blood sugar after the meal. Our guide to the GLP-1 diet shows what that looks like across a day.

The quiet work of the gut bacteria

This is the best-established mechanism, and the least glamorous. The fibre we cannot digest is fermented by bacteria in the colon, which produce short-chain fatty acids: acetate, propionate and butyrate. These molecules bind to receptors on the surface of L cells and trigger the release of GLP-1. Gwen Tolhurst's team at the University of Cambridge described the process in 2012 in the journal Diabetes.

Two practical things follow. The effect builds over several weeks, the time it takes the gut bacteria to adapt. And variety beats quantity, because each type of fibre feeds different bacteria.

The UK recommendation is 30g of fibre a day for adults. According to the NHS, most of us manage about 20g. It is better to close the gap in steps, with plenty to drink, to spare yourself the bloating of the first few days.

Herbs and supplements, ingredient by ingredient

This is where the promises run furthest ahead of the data. The state of play:

Lemon verbena and hibiscus, a lead that needs confirming

The trial quoted most often appeared in 2018 in Food & Function. Overweight volunteers took 500mg a day of a polyphenol blend from the two plants, or a placebo, for two months. In the treated group GLP-1 was higher, the hunger hormone ghrelin lower, and fullness better rated.

The result deserves attention, not excitement. The study is small, the maker of the extract took part in it, and nobody has yet reproduced it independently.

Berberine is not "nature's Ozempic"

The nickname has done the rounds on social media. It is wrong about the mechanism, since berberine does not act like a GLP-1 medicine, and misleading about the outcome: in the trials available, its effect on weight is small.

It also skips over the safety file. In an opinion published in 2019, the French food safety agency ANSES concluded that berberine has pharmacological activity from 400mg a day. It advises against it for pregnant and breastfeeding women, children and teenagers, people with diabetes or with liver or heart conditions, and anyone taking medication. The European Food Safety Authority has since consulted on a draft opinion that could not establish a safe intake, and the UK's Committee on Toxicity discussed that draft in March 2026. The full story is in our guide to berberine, and the nickname gets its own article: natural Ozempic, what the studies say.

Why the comparison with the jabs does not hold

Ozempic, Wegovy and Mounjaro do not "boost" the patient's GLP-1. They are synthetic molecules that lock on to the same receptor and stay there for days, where the natural hormone lasts two minutes.

The results reflect that difference. In the STEP 1 trial, participants given semaglutide 2.4mg (Wegovy) lost on average nearly 15% of their body weight over 68 weeks. In SURMOUNT-1, tirzepatide 15mg (Mounjaro) reached about 21% over 72 weeks. No study of a food, a plant or a supplement comes anywhere near those figures.

These treatments are for specific medical situations. They are prescribed, monitored and dispensed by a pharmacy. Food does not stand in for them. It does a different job, one that stays useful with or without treatment. For the basics of the hormone itself, see what is GLP-1.

What the UK regulators say

NICE recommends semaglutide and tirzepatide for weight management only alongside a reduced-calorie diet and increased physical activity, so eating well is part of the treatment and not a rival to it. The MHRA, which regulates medicines, reminds the public that GLP-1 medicines are prescription-only, should come from a legitimate pharmacy after a consultation with a healthcare professional, and should never be bought from beauty salons or through social media.

On the supplement side, the ASA has been blunt. In the rulings it published on 6 August 2025, it treated claims that a supplement stimulates GLP-1 as medicinal claims, which only a licensed medicine may make. The health claims that do exist are narrow: chromium for blood glucose, glucomannan for weight loss within an energy-restricted diet. Our guide to GLP-1 supplements explains how to read a label with that in mind, and the patches are covered in GLP-1 patches: do they work?.

Where to start

With breakfast, the meal with the least protein in it for most of us: an egg, some yoghurt or a handful of almonds already changes the morning. Then with pulses, three times a week, which bring fibre and protein in one go. Then with pace. Fullness signals take about twenty minutes to arrive, and a meal eaten in ten gets there before they do.

Sleep and movement do the rest. Short nights sharpen the next day's appetite, and a ten-minute walk after eating takes the edge off blood sugar. None of this comes in a capsule.

Frequently asked questions

What is the best natural GLP-1?

No product deserves the title. The most reliable way to stimulate GLP-1 release is a meal that combines protein and fibre. Among supplements, none can claim a proven effect on the hormone.

Which foods increase GLP-1 naturally?

Those that supply protein (eggs, fish, dairy, pulses), fermentable fibre (oats, beans and lentils, onions, leeks) and unsaturated fats (olive oil, avocado, nuts).

Is there a natural Ozempic?

No. Ozempic is a medicine containing semaglutide, prescribed for type 2 diabetes. No food, plant or supplement has a comparable effect, and products sold on that promise mislead the people who buy them.

Does berberine help you lose weight?

Very little, going by the trials available. The French agency ANSES warns of pharmacological effects from 400mg a day and advises several groups against it, including people on medication.

Do GLP-1 patches work?

Nothing shows that they do. No published study establishes that their ingredients cross the skin in useful amounts, or that they change GLP-1 levels.

Can I take a supplement while on a GLP-1 medicine?

That is a question for your GP, prescriber or pharmacist. Some ingredients, berberine and caffeine among them, can interact with treatment or add to its digestive side effects.

This article is for information only and is no substitute for advice from a healthcare professional. Never change your treatment without talking to your doctor.