GLP-1 Supplements, Capsules and Shakes: Do They Work?

Search for GLP-1 and you will find a wave of “GLP-1 support” capsules, drops, powders and shakes. Some claim to boost your own GLP-1, some are sold as a natural alternative to the weight-loss injections, and some are marketed to people already prescribed a GLP-1 medicine. This guide looks at what is in them, what the research shows, the safety warnings from the Therapeutic Goods Administration (TGA), and what actually matters for nutrition if you are taking a GLP-1 medication.

What is in GLP-1 “support” products?

GLP-1 is a hormone your gut releases after eating. It helps regulate blood glucose and appetite. Prescription GLP-1 medicines are long-acting versions of it. Supplements sold for “GLP-1 support” usually contain ingredients such as berberine, fibres like psyllium or glucomannan, probiotics (including Akkermansia), green tea extract, chromium or protein. The marketing idea is that these raise your own GLP-1.

The problem is scale. Your own GLP-1 lasts only one to two minutes in the blood, while the medicines are designed to last for days. A 2025 joint advisory from four US nutrition and obesity societies found that studies on gut bacteria and GLP-1 release are inconclusive.

What the research shows

For comparison, a large trial of a weekly prescribed GLP-1 medicine (semaglutide) found an average weight change of 14.9% over 68 weeks, compared with 2.4% on placebo. The supplements are not in the same category. Fibre from food still has real benefits for gut health and fullness. It just does not act like a medicine.

Safety: what the TGA has warned about

• Fake GLP-1 products. In September 2025 the TGA warned about imported products sold as “GLP-1” oral drops or liquids. In March 2026 it reported that products it had tested in its laboratory contained no GLP-1 or GLP-1 analogue at all, despite their labels.
• Compounded copies. Since 1 October 2024, Australian pharmacies can no longer compound copies of GLP-1 medicines.
• Berberine interactions. Berberine affects several of the liver enzymes that process medicines and can add to the effects of diabetes and blood pressure medicines. Goldenseal, a common source, lowered metformin levels by about 25% in one study and should not be used in pregnancy or breastfeeding.

Labels such as “GLP-1 friendly” or “GLP-1 diet” are not pre-approved health claims under the Food Standards Code. Any health claim on a food must be based on a food-health relationship that has been substantiated under the Food Standards Code.

If you are already prescribed a GLP-1 medicine

What helps is less exciting than a supplement, but it is what the evidence supports. The 2025 joint advisory recommends prioritising protein (it suggests about 80 to 120 g a day, and notes that 1.2 to 1.6 g per kilogram of body weight has been proposed during active weight loss), fibre and fluids from food, and strength training, because protein alone is unlikely to protect muscle. In one major trial, about 38% of the weight lost was lean mass. Shakes, bars and fortified foods can help some people reach their protein needs when appetite is small, but they are one option among many. Supplements may be worth considering for specific nutrients at risk, such as vitamin D, calcium or vitamin B12, ideally guided by your doctor’s blood tests.

Dietitians Australia has called for every person prescribed a weight loss medicine to also be referred to a dietitian. Our guides on what to eat on GLP-1 medication and nutrient deficiencies to watch for go further.

When to talk to your doctor

Talk to your doctor or pharmacist before starting any supplement if you take medicines for diabetes, blood pressure or heart rhythm, if you are pregnant, breastfeeding or trying to conceive, or if you are taking a GLP-1 medicine. If you have bought a product sold as containing GLP-1 without a prescription, stop using it and speak to your doctor. You can report a suspected fake product to the TGA.