Natural Ozempic: berberine, psyllium husk, what do studies say?

The title of "natural Ozempic" has already had several holders. First berberine, a plant extract sold in capsules and soon rebranded "nature's Ozempic". Then psyllium husk, a fibre better known from the constipation shelf. Then a drink of oats blended with water and lime juice, christened "Oatzempic" on social media. Each time the unspoken promise is the same: to get, from a health shop or a blender, what a prescription medicine does.

We went back to the studies cited for each of these candidates. None justifies the nickname, and one of the most quoted has been withdrawn by the journal that published it. Here is what they say, and what they are made to say.

The medicine whose name is being borrowed

Ozempic (semaglutide) is an injectable medicine prescribed for type 2 diabetes. The same molecule, at a higher dose, is licensed for weight management under the name Wegovy. Semaglutide mimics GLP-1, a fullness hormone the gut releases after meals, with one decisive difference: the natural hormone is destroyed in one to two minutes, whereas semaglutide has, according to its product information, a half-life of about a week. Our explainer what is GLP-1 covers the basics.

The results follow from that duration of action. In the STEP 1 trial, published in 2021 in the New England Journal of Medicine, participants treated with semaglutide 2.4mg lost on average 14.9% of their weight in 68 weeks. That figure, obtained under medical supervision and with documented side effects, is the yardstick any pretender to the nickname would have to be measured against.

Berberine, social media's first natural Ozempic

Berberine does not mimic GLP-1 and its effect on weight is modest. This alkaloid, extracted from barberry among other plants, has been through clinical trials, which sets it apart from most of its rivals. A meta-analysis pooled twelve of them in 2020 in Clinical Nutrition ESPEN. Its authors conclude that weight fell by an amount they themselves describe as moderate, bearing no relation to what is seen on treatment.

The main problem lies elsewhere. In an opinion issued in 2019, the French food safety agency ANSES found that berberine has pharmacological activity from 400mg a day. The agency advises against it for pregnant and breastfeeding women, children and teenagers, people with diabetes or with liver or heart conditions, and anyone taking medication. A product that a health agency likens to a medicine in its effects, without the assessment or the monitoring a medicine receives, deserves better than a flattering nickname. Our guide to berberine has the whole file, including the European safety review now under way.

Psyllium husk, an honest fibre under the wrong name

Psyllium works by a purely physical mechanism, with no link to the GLP-1 receptor. Its fibres absorb water, form a gel in the stomach and intestine, and slow the passage of food. You feel full for longer.

A meta-analysis of six trials, 354 overweight participants in all, concluded in 2023 in the Journal of the American Association of Nurse Practitioners that psyllium has a favourable effect on weight when taken before meals for several months. Two details help in reading it. The effect reported is limited. And its three authors are employees of Procter & Gamble, a company that sells psyllium, as their affiliations state.

None of that disqualifies the fibre, which is useful in other ways. It disqualifies the comparison.

"Oatzempic", a recipe with no study behind it

No clinical trial, to our knowledge, has evaluated the blended oat drink popularised under that name. So the reasoning has to go by its ingredients. Oats supply beta-glucans, viscous fibres for which there are authorised health claims on cholesterol and on the rise in blood glucose after a meal, at specified doses. None concerns weight.

What remains is a rather ordinary substitution effect. A glass of oats and water in place of a bigger breakfast means fewer calories in the morning. The same oats eaten as porridge, with a spoonful of yoghurt, would probably keep you fuller, since they would come with some protein.

Apple cider vinegar and the retracted study

The strongest argument for apple cider vinegar no longer exists. It rested on a Lebanese trial published in 2024 in BMJ Nutrition, Prevention & Health, which reported marked weight loss in 120 teenagers and young adults. The journal retracted it in September 2025. Statisticians commissioned by the publisher could not reproduce the results and found multiple errors of analysis; nor had the trial been registered before it began, as publication rules require.

What is left is thin. A systematic review in the European Journal of Nutrition, 2020 judges the evidence insufficient to draw conclusions.

Why the nickname does not hold

Three reasons are enough. Mechanism first: none of these products binds to the GLP-1 receptor or stays there for days. Scale next: the effects measured, where there are any, are out of all proportion to those of the semaglutide trials. Then the setting. A medicine is prescribed for a specific situation, its dose is adjusted, its effects are monitored. A supplement ordered online offers none of that, and "natural" does not mean harmless, as the ANSES warning on berberine shows.

The UK's advertising watchdog has reached the same conclusion by another route. In August 2025 the Advertising Standards Authority ruled against supplement adverts that used lines such as "like GLP-1 drugs just natural" or presented berberine as a "natural GLP-1 secretion enhancer". It treated these as medicinal claims, which a food supplement is not allowed to make, because they implied a comparison with prescription-only injections.

There is also what the nickname makes people forget. The treatment itself works only for as long as it is taken: a year after stopping semaglutide, the participants followed in the extension of STEP 1 had regained two thirds of the weight they lost, according to the results in Diabetes, Obesity and Metabolism, 2022. If a medicine of that strength does not settle the matter once and for all, a capsule of plant extract will not. We go through those withdrawal trials in coming off Mounjaro or Wegovy.

What is left when you peel off the label

The body makes its own GLP-1, and we know what favours its release: protein and fibre at each meal, time spent at the table, sleep, movement. The effect is real, modest and short-lived. It does not compare with any treatment and does not need to in order to be worth having. Our piece on natural GLP-1 separates what is established from what is marketing, and the guide to GLP-1 supplements shows how to read the labels of the products that trade on the name.

For anyone wondering whether a treatment is right for them, the answer is not in a social media feed or on the supplement shelf. It is something to discuss with a GP or a qualified prescriber.

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.