GLP-1 supplements: how to choose one without being misled

Pick up any of the GLP-1 supplements now on sale and turn the pack over. In the ingredients list you will find some fibre, a mineral, two or three plant extracts, sometimes caffeine. You will not find GLP-1. The hormone printed in large letters on the front is missing from the contents, and for good reason: it is a fragile peptide that digestion would destroy.

That gap between the name and the contents does not write off the whole category. It does call for a different method. A "GLP-1" product should be chosen on its formula, read the way you would read any label, and never on its promise. This guide offers a way of reading. It does not rank brands.

What GLP-1 supplements really are

A GLP-1 supplement is an ordinary food supplement, built from fibre, plant extracts or minerals, to which its maker has given a name borrowed from pharmacology. Nothing more.

The law is clear on two points. A food supplement is a food, not a medicine: it goes on sale without anyone having to show beforehand that it works. And the register of authorised nutrition and health claims contains none that refers to GLP-1 or to satiety. On a pack, the letters "GLP-1" therefore tell you the manufacturer's intention. They correspond to no recognised effect, and no brand is allowed to state that its product raises the hormone.

The Advertising Standards Authority has enforced exactly that. On 6 August 2025 it published rulings against several supplement adverts that spoke of boosting or stimulating GLP-1, on the grounds that such wording implies a comparison with prescription-only weight loss injections and so amounts to a medicinal claim. A further ruling in July 2026 dealt with a "GLP-1 patch" in the same way.

The mechanisms the marketing leans on, from fibre slowing the stomach to the role of gut bacteria, are unevenly documented. Our piece on natural GLP-1 takes each in turn.

The ingredient families and their evidence

Nearly every formula draws on the same five families. Their evidence runs from solid to fragile.

Fibre, provided there is enough of it

This is the best-supported family, and the one where the dose most often lets the formula down. The glucomannan claim requires 3g a day, in three 1g doses before meals, with one or two glasses of water, as part of an energy-restricted diet. With capsules of half a gram the sum is quickly done: six a day, at the very least.

Trials of soluble fibre and fullness also give uneven results from one fibre to the next, and carob gum has no authorised claim in this area.

Chromium, a narrow claim

Chromium contributes to the maintenance of normal blood glucose levels. That sentence may be used once the daily dose supplies at least 15% of the reference value, which is 6 micrograms. It says nothing about hunger or weight, and a manufacturer who stretches it that far has left the rules behind.

Plant extracts, somewhere between a lead and set dressing

The lemon verbena and hibiscus blend is the best documented of the lot: five publications in humans, at 500mg a day of a standardised extract, among them the controlled trial published in Food & Function in 2018. All have a link to the maker of that extract, and the results on GLP-1 itself contradict one another. A formula containing 50mg cannot lean on them.

Guarana is caffeine

Guarana supplies caffeine under another name. In its opinion in the EFSA Journal, 2015, the European Food Safety Authority considers that a healthy adult can have up to 400mg a day from all sources, and 200mg in a single dose. The morning coffee counts towards the total, and so does the afternoon tea. A serious label states the amount of caffeine per serving.

Berberine, a case apart

In 2019 ANSES, the French food safety agency, published an opinion that sets berberine apart from the other ingredients. From 400mg a day, the agency considers that it has pharmacological activity. 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. Our guide to berberine goes through that opinion and the European review that has followed. Whether a "GLP-1" formula contains berberine is the first thing to look for.

Reading the label: dose before name

A useful label gives the quantity of each active ingredient per daily dose. Everything else is secondary.

Be wary of "complexes" and "proprietary blends" where only the total weight is disclosed. If eight ingredients share 600mg, none reaches the dose at which it was studied. For plant extracts, the detail that counts is standardisation: a lemon verbena extract is only as good as its verbascoside content, a hibiscus extract its anthocyanins.

UK regulations also require certain statements on every food supplement: the recommended daily dose, a warning not to exceed it, a reminder that supplements are not a substitute for a varied diet, and an instruction to keep the product out of the reach of young children. Their absence tells you something about the seller.

Promises that should ring alarm bells

Some wording is enough to rule a product out, because no supplement is allowed to use it.

A number of pounds or kilos, a deadline, an effect on a disease: the rules on health claims forbid all three. A comparison with a medicine credits the product with properties it has never demonstrated, and it is precisely what the ASA upheld complaints about. Regulators' logos are another signal. The French medicines agency has reported finding websites that displayed its logo, or that of the European Medicines Agency, to look legitimate.

The MHRA's own reminder is worth keeping in mind. Genuine GLP-1 medicines are prescription-only, supplied by a registered pharmacy after a consultation with a healthcare professional. Anything offered as the real thing by a beauty salon or through social media is, in the regulator's words, against the law.

Customer reviews call for the same caution. They cannot separate the effect of the product from that of the diet started on the same day.

Who should ask first

A supplement is not harmless just because anyone can buy it. Several situations call for a word with a GP or pharmacist beforehand.

The first is taking any medicine at all. Viscous fibres can delay its absorption, ANSES advises anyone on medication against berberine, and caffeine adds to other stimulants. The question also arises for people on weight loss injections: these medicines already slow the emptying of the stomach, and adding gel-forming fibre or a stimulant on top is not a decision to take alone.

The others are pregnancy, breastfeeding, diabetes, liver, heart or kidney disease, and difficulty swallowing in the case of fibres that swell. If something unexpected happens after starting a supplement, stop taking it and tell your pharmacist or GP.

The real price is the price per month

The price of a pack means nothing until it is set against the effective dose.

Take a tub of 90 glucomannan capsules at 500mg each. At 3g a day it lasts fifteen days, and not the three months that the number 90 suggests. The real monthly cost is therefore twice the price on the shelf.

The rule is one line of arithmetic: price of the pack, divided by the number of days it covers at the dose that was studied, multiplied by thirty. A product that looks cheap because it is under-dosed often works out dearer than its neighbour.

Capsules, powder, drops, patches

Format matters less than dose, with two exceptions.

Fibre does not suit capsules well: reaching several grams a day means swallowing a lot of them, and a powder to stir into water is more realistic. Drops, at the other extreme, can only hold tiny quantities of anything active. As for patches, they are not food supplements at all, since they are not swallowed, and nothing shows that their ingredients cross the skin. We cover them separately in GLP-1 patches: do they work?.

When the real need is simply to eat enough

Some people looking for a "GLP-1" supplement actually have a different problem: a reduced appetite, meals that keep getting shorter, a protein intake that is sliding. None of the ingredients reviewed above addresses that.

In that case the priority is food. When appetite is low, small and frequent helpings of protein-rich foods, such as yoghurt, eggs, milk, fish or lentil soup, do more than any capsule, and our GLP-1 diet guide shows how to fit them into a day.

For everyone else too, the first lever is still the plate: protein at each meal, beans and lentils, vegetables, and time to eat them. And if what you are after is the effect of a medicine, no supplement will supply it, a point made at length in natural Ozempic: what the studies say.

Frequently asked questions

Can a supplement contain GLP-1?

No. GLP-1 is a fragile hormone, destroyed by digestion, and the medicines that mimic it are prescription-only. A supplement carrying the name contains fibre, plant extracts or minerals.

What is the best GLP-1 supplement?

No product can claim the title, since none has demonstrated an effect on GLP-1 to the satisfaction of regulators. Judge a formula on its doses, the evidence for each ingredient and how openly it is labelled.

Do GLP-1 supplements help with weight loss?

The only ingredient whose authorised claim mentions weight loss is konjac glucomannan, at 3g a day and as part of an energy-restricted diet. For the rest, nothing of the kind is established.

Are GLP-1 supplements sold in pharmacies?

Some are, as they are in health food shops and online. Where a product is sold does not change its status: these are foods, and they have not been assessed the way medicines are.

Can I take one alongside Mounjaro or Wegovy?

Only your prescriber or pharmacist can say, knowing both the treatment and the formula. Gel-forming fibres, caffeine and berberine are the ingredients to mention first.

What side effects are possible?

It depends on the ingredients: bloating with fibre, jitteriness or poor sleep with caffeine. Berberine is the subject of a warning from the French agency ANSES. Anything unexpected is worth reporting to a pharmacist or GP.

How much do GLP-1 supplements cost per month?

The shelf price is often misleading. Divide the price of the pack by the number of days it covers at the dose that was actually studied, then multiply by thirty.

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.