GLP-1 supplements: do they work?

What is GLP-1 and how does it work in your body?

GLP-1 is a hormone your gut makes itself as soon as you eat. It slows your gastric emptying, so you feel full for longer. It signals to your brain that you've had enough, and it helps keep your blood sugar stable.

That interplay largely determines how much hunger you experience during the day. In people with excess weight, that satiety signal often works less strongly or too briefly. You don't eat because of a lack of willpower, but because your body simply sends the "I'm full" signal later.

Medicines based on GLP-1, such as semaglutide, tirzepatide and liraglutide, mimic this hormone at a much higher and longer-acting dose than your body reaches itself. Supplements try something else: giving your own production a nudge. That is a fundamental difference in how they work, and therefore also in what you can expect from them.

What is in GLP-1 supplements? Capsules, drops and ampoules

GLP-1 supplements contain no GLP-1, but a mixture of fibre, plant extracts, vitamins and minerals. The most common ingredients are berberine, psyllium fibre, bitter melon, green tea extract, chromium and citrus extracts.

You'll come across them in three forms. GLP-1 capsules are the standard and usually contain a fixed combination of those ingredients. GLP-1 drops are the same category in liquid form, with the promise of faster absorption. You'll also see GLP-1 ampoules offered online, and that's where you need to pay attention: ampoules suggest an injectable product, while injectable GLP-1 in the Netherlands is only available on prescription through a pharmacy.

The logic behind the fibre is not nonsense in itself. Fibre slows your gastric emptying and increases your feeling of fullness, which is what every appetite suppressant tries to achieve. The difference lies in the size of the effect: a fibre supplement gives a slight, short-lived dampening of your hunger, not a structural change in your eating pattern.

What does the evidence say about GLP-1 supplements?

There is no supplement for which clinically relevant weight loss has been demonstrated. The Voedingscentrum (the Netherlands Nutrition Centre) is clear about this: the effect of no single slimming product has been demonstrated, and studies show no or minimal effects on body weight.

Take berberine, often promoted online as natural Ozempic. UCLA Health concludes that the evidence is inconclusive: there are no large randomised trials, the mechanism of action differs fundamentally from that of GLP-1 medication, and there are known interactions with diabetes medication, among others, and with medicines that are broken down by the liver.

On top of that, food supplements are not assessed in advance the way medicines are. What's on the label is not always what's inside, and side effects have rarely been studied systematically. "Natural" doesn't automatically mean safe.

To be fair: a supplement with fibre can help you feel full a little sooner at a meal. That is a gain, but it is something different from the promise they are sold with.

Can I lose weight with a GLP-1 supplement?

With a supplement alone you rarely lose a meaningful amount of weight. The small effect that fibre has on your fullness disappears into the noise as soon as your eating pattern, sleep, stress or hormones work against you.

For some people, a pot like that works as a bit of extra support for an approach that is already under way. For many people with a BMI of 30 or higher it is mainly an expensive detour, after which the disappointment is greater than before. We recognise that pattern in the people who come to us: they have often already made several serious attempts.

A medical programme is not an easier route, but it is a different one. Above all, it takes away the feeling of hunger, so the lifestyle changes you already know suddenly become sustainable. That also comes with GLP-1 side effects, such as nausea and bowel complaints in the first weeks. That is part of the full picture.

Tried everything and still not losing weight? At Qlinic, your own BIG-registered doctor (the BIG register is the Dutch register of healthcare professionals) personally assesses whether a medical programme suits you, with a check-up every four weeks and home delivery through a registered Dutch pharmacy. See if it's right for you →

GLP-1 supplement or medical programme: the differences

The biggest difference is legal and medical: a supplement is food, medication is a registered medicine. Everything else follows from that.

That difference in evidence is large. In the STEP 1 trial among 1,961 adults, participants on weekly semaglutide with lifestyle support lost an average of 14.9% of their body weight after 68 weeks, compared with 2.4% in the placebo group. Figures like these don't exist for any GLP-1 supplement.

Important here: medication doesn't replace good nutrition. Precisely because you start eating less, enough protein, vitamins and minerals become more important. That is exactly where supervision by a doctor makes the difference.

When is medical weight loss with a doctor a sensible choice?

Medical weight loss is intended for people for whom excess weight has become a medical problem and for whom lifestyle alone turns out not to be enough. Think of a BMI of 30 or higher, or a lower BMI in combination with health problems.

Whether it suits you is decided by a doctor. With us, you first do a short check and then have a consultation with a BIG-registered doctor, who remains your own point of contact. If you receive a prescription, the medication is delivered to your home through a registered Dutch pharmacy.

Every four weeks you talk to that same doctor about your progress, your side effects and your dose. Most people notice the first effects after about four weeks.

We are a small-scale clinic: you have one BIG-registered doctor as your point of contact throughout your whole programme. Around fifty people have gone before you and rate us 5.0 on Google, based on more than twenty reviews.

Unsure whether to keep trying on your own or get medical support? Within a few minutes you'll know whether a programme with your own doctor is an option for you, with no obligations. See if it's right for you →

Frequently asked questions about GLP-1 supplements

Can I lose weight with a GLP-1 supplement? Meaningful weight loss is not to be expected from a supplement alone. Fibre-rich supplements can slightly increase your feeling of fullness, but for no slimming product has a clinically relevant effect on weight been demonstrated. Structural results require changing your eating pattern, or medical treatment if that turns out not to be enough.

What is the best GLP-1 supplement? There is no supplement that demonstrably works better than the rest, because none of the products has a proven effect on weight loss. Reviews and rankings from online shops say something about taste, price and packaging, not about effectiveness. Watch out above all for unrealistic promises and missing ingredient information.

How much weight do you lose with GLP-1? With GLP-1 medication plus lifestyle support, participants in the STEP 1 trial lost an average of 14.9% of their body weight after 68 weeks. The outcome varies greatly from person to person and depends on dose, type of medication, diet and exercise. Results like these have not been demonstrated with supplements.

Is GLP-1 good for you? GLP-1 is a hormone your body makes itself that regulates your hunger and blood sugar, so in itself it is indispensable. GLP-1 medication is effective and approved for the right target group, but it has side effects such as nausea and bowel complaints and is not suitable for everyone. A doctor assesses whether it is responsible in your case.

When should you take a GLP-1 supplement? Manufacturers usually advise taking it just before a meal, because that's when fibre has the most effect on your fullness. There is no medically supported dosing schedule. If you take medicines, for example for diabetes or your thyroid, first check with your doctor or pharmacist about possible interactions.

Can you buy GLP-1 online or order ampoules? Supplements are freely available, but injectable GLP-1 is prescription-only and may never be sold online without a prescription. That is prohibited by law, the CBG warns, because you don't know what you're buying. The safe route always goes through a doctor and a registered pharmacy.