GLP-1 supplements, explained

What is GLP-1?

GLP-1 (glucagon-like peptide-1) is a hormone made by cells in the lining of your gut and released when food arrives. Its main jobs are to prompt the pancreas to release insulin as blood glucose rises after a meal, to slow the rate at which your stomach empties, and to act as one of several signals involved in appetite (Holst, 2007).

It doesn't last long. An enzyme called DPP-4 breaks natural GLP-1 down within about two minutes, according to a 2025 review of how GLP-1 medicines behave in the body, so your gut releases it in short bursts around meals and your body clears it almost as quickly.

What are GLP-1 medicines?

GLP-1 medicines are prescription-only drugs that act on the same receptor as your own GLP-1 but are built to resist that breakdown, so they stay active for days instead of minutes. Semaglutide has a half-life of about seven days and tirzepatide about five, which is why the injections are taken once a week (Min and colleagues, 2025).

The UK-licensed ones include semaglutide (sold as Wegovy for weight management, and as Ozempic and Rybelsus for type 2 diabetes) and tirzepatide (Mounjaro, licensed for both). Tirzepatide also acts on a second gut hormone, GIP. In June 2026 the MHRA licensed the first GLP-1 tablet for weight management, a daily semaglutide tablet, and it is prescription-only like the rest.

Getting them on the NHS

In England, NICE recommends semaglutide for weight management only within specialist weight management services, for up to two years, in adults with at least one weight-related health condition and a BMI of at least 35 (or 30 to 34.9 if they meet the criteria for specialist referral). That guidance is NICE TA875. Under NICE TA1026, tirzepatide is recommended for adults with a BMI of at least 35 and at least one weight-related condition, and NHS England is introducing it in phases, starting with people who have the highest BMI and several weight-related conditions. Lower BMI thresholds apply to people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds. Those details are for England, so ask your GP how it works where you live.

Getting them privately

A private GLP-1 medicine still needs a prescription, issued after a consultation with a healthcare professional, and should come from a registered pharmacy. You can check an online pharmacy in Great Britain on the General Pharmaceutical Council's register (MHRA). There is no over-the-counter route: every GLP-1 medicine in the UK is prescription-only.

What's actually in a GLP-1 supplement?

Whether it's labelled a GLP-1 supplement or a natural GLP-1 supplement, it is a food supplement, which in UK law is a food meant to add to a normal diet. Government guidance for businesses says food supplements are not medicinal products and cannot exert a pharmacological action. The usual ingredients are fermentable fibres, berberine, probiotics such as Akkermansia, mulberry leaf, yerba maté and chromium.

Across the table, the studies are small and short, and many measure markers such as blood glucose rather than anything you would notice day to day. Some were funded or co-written by people linked to the company selling the ingredient. None compares an ingredient with a GLP-1 medicine.

Berberine also has real safety caveats. It can interact with medicines, and the US National Center for Complementary and Integrative Health says it may be unsafe in pregnancy or while breastfeeding. Our berberine guide covers it in detail.

Do GLP-1 supplements work?

Not in the way the name suggests. No supplement ingredient has been shown to act like a GLP-1 medicine, and timing is part of the reason: even if an ingredient nudged your own GLP-1 after a meal, your body would clear that hormone within minutes, while the medicines are engineered to keep working for days.

The GB register of nutrition and health claims lists every health claim a food or supplement may make in Great Britain. None of the authorised claims mentions GLP-1, appetite or fullness, and claims about feeling full submitted for protein, oat fibre, whole grains and other foods were assessed and not authorised. A label promising to boost GLP-1 is making a claim no food is permitted to make.

If you want to know what food itself can do, our guide to protein, fibre and meal order looks at those studies and how big the effects were.

Why is "nature's Ozempic" the wrong idea?

Because it implies a supplement can do what a licensed medicine does, and UK regulators treat that as misleading. In August 2025 the Advertising Standards Authority ruled against an ad for a berberine supplement billed as a natural GLP-1 secretion enhancer. The ASA said claims that a supplement affects GLP-1 production are medicinal claims, because they invite a comparison with prescription-only GLP-1 injections (ASA ruling). It has ruled the same way on other supplement ads since.

Licensed medicines have been assessed by the MHRA and approved as safe and effective for specific uses, and no supplement has been through that process. Berberine, often called nature's Ozempic online, shows an average weight difference of under 1 kg across its trials.

What are the red flags?

The most dangerous products in this area are the ones claiming to contain a real GLP-1 medicine without a prescription. Watch for these:

• It says it contains semaglutide, tirzepatide or retatrutide, and you can buy it without a prescription. That is illegal supply. In October 2025 the MHRA dismantled a facility in Northampton and seized more than 2,000 unlicensed retatrutide and tirzepatide pens (MHRA).
• It arrives as a powder in a vial that you mix before injecting. The MHRA says these are not authorised.
• It's sold through social media, a beauty salon, or anywhere that skips a consultation with a prescriber.
• It's a "GLP-1 patch". Licensed GLP-1 medicines come as pre-filled pens or tablets, so a patch that says it delivers one is not a licensed medicine.
• A supplement says it boosts GLP-1, quietens food noise or works as an alternative to injections. Under the ASA rulings above, those are claims a food supplement can't make.

How do you judge a GLP-1 supplement label?

Read the label for what is in it and how much, and set the promises aside. A short checklist:

1. Look for the words "food supplement". UK labels must use that term, list the amount of each active substance, give a daily dose with a warning not to exceed it, and say that supplements shouldn't replace a varied diet.
2. Check the amounts. A "proprietary blend" with no quantities can't be compared with any study.
3. Compare doses with the research. A study that used several times the label's dose tells you little about the product.
4. Check the wording of any claim. Authorised claims are specific and plain, such as chromium contributing to the maintenance of normal blood glucose levels. Anything about GLP-1, cravings or food noise is not authorised.
5. Look for caffeine. Yerba maté contains it naturally, which matters if you're pregnant, breastfeeding or sensitive to it.
6. Ask a pharmacist first if you take any medicines, particularly for diabetes, or if you're pregnant or breastfeeding.

What if you're considering a GLP-1 medicine?

Start with your GP, or with the prescriber at a registered pharmacy if you're going private. They can check whether a medicine is suitable for you, which matters because these medicines have side effects (most commonly nausea, vomiting and diarrhoea) and aren't used in pregnancy or while breastfeeding. If you're already taking one, our guide to eating well on Mounjaro or Wegovy covers food and drink alongside treatment.