What you need to know about weight loss jabs and supplements

Rob Lilley-Jones: New year, new you – but at what cost? Welcome to this podcast from Which?

Rob Lilley-Jones: Hello, it is Rob Lilley-Jones here with a brand-new series of our health and wellbeing podcast, bringing you expert advice and recommendations to help you live your best life every day. Now, January is of course a big month for health, with plenty of us making New Year’s resolutions to improve our health for the year ahead. But it is more important than ever to ensure you have taken on board the right advice and you have got it from the right place.

Today’s episode is all about weight-loss jabs and supplements. Later on, we will be joined by our public health nutritionist, Shefalee Loth, and Sophie Medlin, the founder of City Dietitians. But first, we are joined by Which? researcher, Megan Thomas. Megan, hello

Megan Thomas: Hi

Rob Lilley-Jones: How are you doing? You okay?

Megan Thomas: I am good thanks. How are you?

Rob Lilley-Jones: I am very good, thank you. It is brilliant to have you on the podcast. Now, I have already said we are talking about weight-loss jabs and supplements, so why are you here? What have you been investigating in that space?

Megan Thomas: I have been looking at food supplements specifically, and the kind of weight-loss claims we might be finding out there – whether that is in the supermarkets, in major pharmacy retailers or on online marketplaces. It is a bit of a wild west; there is a lot going on.

The headline from your findings: the supplement market is full of dodgy weight-loss claims, even from reputable retailers. There are very specific approved weight-loss claims that a product could make based on very specific ingredients. Because it is a health claim you cannot just say things willy-nilly. But when we are looking at these products, we are hearing things such as: it is a fat burner, it is an appetite suppressant. And then you look at the ingredients list and you are not really seeing any justification for that.

That is definitely more so on the online marketplaces because it is so hard to control. But because these major retailers need to keep up with the sort of things that online marketplaces are offering, we are seeing a bit of that there as well, where the claims are maybe just stretching out what is allowed a bit. They might be allowed to say "contributes to a normal metabolism", but that is being stretched out to say "it will help you with weight loss", which is not necessarily helpful for consumers.

Rob Lilley-Jones: You have touched on a few of them there, but some of the claims you have seen – can you tell us about some of them? Because a lot of them, as you have said, they are just not true

Megan Thomas: Some of the most egregious are just completely absurd and will be easy to spot by consumers. Things like "burns fat in five seconds" was one that I saw. "Within a week you will have lost centimetres off your waistline" and things like that

Rob Lilley-Jones: Now is that easy to spot simply because the normal person would just look at that and go, that is not possible?

Megan Thomas: You just go, "Ah, probably not". Some of them are coming with these really weird images and sometimes it is broken English and you are confused by the message. But other times they are a little bit more believable: fat burner, appetite suppressant, appetite control, things like this, or specific claims about ingredients that actually when you look them up are not backed by science at all and have actually been specifically rejected as unproven. So they should not be being used.

But there are quite a few on hold claims, which means they have neither been proven nor disproven, but a brand can use them while they wait for that decision as long as they have evidence to back it up. This is where we are seeing the system being abused, especially with an ingredient like green tea, which you see in loads of these supplements and is being used to justify anything. Some of these really bold claims, especially fat-burning ones, are coming from the use of green tea as an ingredient but it is not necessarily all there

Rob Lilley-Jones: Do you mean literally green tea that we drink? Or is it a different form?

Megan Thomas: It depends. It is sometimes an extract or a really concentrated form

Rob Lilley-Jones: One of the very few things that do make sense because it is very, very confusing. You mentioned as well there are only specific claims that they can make. Now there is a difference between what supplements can claim they can do and authorised and approved claims that they are allowed to make

Megan Thomas: When you see a supplement that is suggesting that they can put a timeline on your weight loss, do not believe it. Another thing like that is suggesting that you would never gain that weight back – that is another sure-fire red flag that that is not to be trusted.

Another thing is if it is comparing itself to weight-loss jabs. What this is is not even a health claim but a medicinal claim, which are slightly different, which again, confusing. But this means that when it makes a medicinal claim it will actually be regulated differently by the medicines regulator instead of the Food Standards Agency and the Food Standards Scotland who would regulate food supplement claims. It would need to have all these authorisations that it probably does not have if it is trying to sell itself as a food supplement. It just becomes really tricky

Rob Lilley-Jones: We have just made evidently clear why this is so confusing because there are different authorities involved, there are different bodies involved, there are so many different things to consider here. One thing we have not touched on yet and you did allude to it a little bit earlier on, the type of advertising that is used to try and sell these products. The sort of imagery that we are seeing online. Talk us through some of the stuff you saw

Megan Thomas: I have seen so many AI-generated ones – someone who is overweight and then the same person who is super thin, which is obviously just not real. It might be people suggesting wearing oversized jeans that they have lost all this weight from using this product, but that is not true

Rob Lilley-Jones: I think we can all imagine exactly the type of image. And the sheer number of adverts that are out there as well just shows how exponentially this space has grown in recent years. There is more and more interest in this than maybe ever before and do you think social media has a lot to do with that?

Megan Thomas: Definitely. A lot of the ways we have seen social media adverts play into this is that people are finding themselves facing up against these rules too. One instance I saw actually was someone promoting a specific product I had found that was making sketchy claims. There was a conversation in the comments of someone else trying to promote this product and they said they had received a strike because they had alluded to weight loss. They were like, "No, you cannot use those specific words, you have to be a bit more tricky about it" and encouraging people to look it up separately as an interesting way round it.

But with this huge explosion of online marketplaces, there are so many supplements to choose from. Because they are often being imported, it is harder to track down bad players and so people can get away with these sketchy things

Rob Lilley-Jones: And it is not just manufacturers who are making some of these claims that we are seeing in adverts, it is also the retailers as well

Megan Thomas: Sometimes the product itself will not have any claims, but the way it is categorised in the website, it might actually say, "This is a fat burner". But they have been mindful that they could not claim in the product listing or on the bottle itself that it had any weight-loss properties. Similar with appetite suppressants or just weight management, weight loss. If you are looking because these are reputable retailers sometimes, if you are looking at one of those sections, look at the product itself because you might find that there is no evidenced claims that they can use

Rob Lilley-Jones: A bit later in the episode we will be going into even more of the specifics of what you should be looking for to make sure that what you are buying is indeed legit. When it comes to your investigation, Megan, where can people read more, how can people read more – give us a little taste of what they can expect, which of course you have done on this episode already?

Megan Thomas: It should be available on which.co.uk. We will be able to go into the details, maybe picking out some specific examples and saying where has this claim come from and the answer often being nowhere

Rob Lilley-Jones: Well, I am delighted to say we are now joined by Shefalee Loth and Sophie Medlin. Guys, welcome

Shefalee Loth: Thank you

Sophie Medlin: Thank you

Rob Lilley-Jones: Always good to have you here. Now, Shefalee, we have just heard more about Megan’s investigation. How shocked have you been by what she has found?

Shefalee Loth: Honestly, not very shocked. Megan’s done a few investigations over the last few months and supplements is something we have worked on at Which? for a long, long time, and we know that there are crazy things out there being promoted to consumers

Rob Lilley-Jones: And Sophie obviously we have had you on the podcast many times before, we have been talking about supplements a lot. How do you view weight-loss supplements? Where do you stand on them?

Sophie Medlin: I am a wildly sceptical person about weight-loss supplements, and there are so many more on the market now. Because of the new weight-loss injections, GLP-1s that are coming out onto the market, other companies are now looking at those and thinking, "Oh we need a supplement alternative to this that is cheaper". The market is now flooded with ones that are supplements that are pretending to be mimicking GLP-1s. The most important thing to remember is there is no registered health claims for any weight-loss supplements. Anything that is making a claim about that we need to be really sceptical of

Rob Lilley-Jones: And a couple of things there, Sophie. GLP-1s?

Sophie Medlin: GLP-1s

Rob Lilley-Jones: GLP-1s, what are they?

Sophie Medlin: GLP-1s are weight-loss medications, the injectable medications that people will have seen everywhere now. We are talking about things like Ozempic and Mounjaro and those types of products, which are really effective for weight loss, but are a very different thing and work very differently than the supplements that people are selling

Rob Lilley-Jones: We will be mentioning and talking about Ozempic and Mounjaro in a little bit. But also, we did touch on this with Megan around health claims, what claims can and cannot be made. Just go into a little bit more what you mean there around the claims that can and cannot be made in this space

Sophie Medlin: There is no registered health claims for anything regarding weight loss. That means that anyone who is saying can support weight loss, can aid in weight loss, any of the claims that you see out there are actually using those claims illegally and you can report them to the ASA for that, the Advertising Standards Authority

Rob Lilley-Jones: This is not something we have reviewed before here at Which? But if people think they are necessary, if people really want to take some of these weight-loss supplements, what are the things they should be considering before they even go out there and look for them?

Sophie Medlin: Supplements, as we have said multiple times on this podcast, are the icing on the cake. And the answer to weight loss, unfortunately, is really boring and it is energy in, energy out. So trying to eat a bit less and move a bit more. There is some suggestion or some supporting evidence for fibre-based supplements and how they can help maybe to keep you fuller for longer and fuller between meals. Those sorts of fibre supplements are not providing any magic formula; they just may support you to regulate your appetite a bit better

Rob Lilley-Jones: That point on fibre is really interesting, is it not, Shefalee? Because you have spoken a lot about fibre, people will have seen you on our social media videos, on all of our channels, they will have seen you write about fibre a lot in Which? magazine as well. The value of fibre in our diet we cannot really underestimate it

Shefalee Loth: No, and I think especially recently there has been a real push for protein. But actually most of us have enough protein in our diets and it is really the fibre that is deficient. There are so many benefits to fibre. As Sophie said, it can really help regulate your appetite, it slows down your digestion, so it helps you to feel fuller for longer. Increasing your fibre intake gradually is something that you can really do

Rob Lilley-Jones: 30 grams is that roughly what we should be aiming for?

Shefalee Loth: That is the aim, yes. But the research shows most people are getting about 18 grams a day. Wildly deficient of that

Rob Lilley-Jones: So before we get onto weight-loss jabs then, weight-loss supplements, are they nonsense? Do we need to bother at all?

Sophie Medlin: Nonsense and potentially unsafe as well, so definitely avoid

Rob Lilley-Jones: Weight-loss jabs then, Shefalee. They have boomed over recent years. We have mentioned two of the names, two of the most popular, Mounjaro, Ozempic. Are they effective?

Shefalee Loth: They are really effective. Ozempic is not traditionally the weight-loss medication. It is the drug semaglutide which has been used to treat diabetes patients. And the weight-loss version of the same drug is called Wegovy. If people are using one of these injections for weight loss it will either be Mounjaro or Wegovy that they will be using. And they are really, really effective. In trials people have lost up to 22 per cent of their body weight

Rob Lilley-Jones: Is that safe though if you are losing that percentage of your body weight?

Shefalee Loth: It depends how you are using them. If you are using them under medical supervision and for the right purpose then yes, that is safe. If you think about it, if people are obese, morbidly obese, they are likely to have a lot of other health conditions as well, co-morbidities such as high blood pressure, high cholesterol, diabetes for example. By reducing your weight you can also reduce your risk or incidence of those diseases. If you are using it to lose a few pounds, then no, it is not safe to be losing 22 per cent of your body weight

Rob Lilley-Jones: You have almost touched on my next question there which is who are they for? Who should they be for? Because it sounds like they should not be for everyone

Sophie Medlin: I think really the criteria for taking them is that you are obese in the first place and you have co-morbidities. It is looking at diabetes, cardiovascular disease, maybe fatty liver, but also that you are also overweight because these are what the indication is for. Used under those circumstances, the benefits outweigh the risks. We know that people are going to enjoy longer healthier lives. The problem we are finding is that young people, young women especially are getting their hands on them when they have got a BMI, body mass index that is already in the healthy range, or they are not even over 18 years old which the drugs are indicated for. Them getting into the wrong hands is the problem that we are contending with at the moment

Rob Lilley-Jones: The people who are taking them who probably should not be taking them, how much of that is down to the marketing of these products and some of the marketing that is out there? We touched on this with Megan around some of the weight-loss supplements previously

Shefalee Loth: The drugs are not necessarily marketed towards a consumer audience. But that does not stop influencers or celebrities using them and then people seeing that, either online or in the press and thinking, "Actually, this is a really appealing way for me to lose those stubborn pounds that I cannot seem to shake". If everyone else is using them, why cannot I?

Rob Lilley-Jones: The big question for me is how do they work? Because it seems like some pretty clever science going on to be able to make people lose weight as quickly as they often do

Sophie Medlin: They are amazing really when we look at them. Our bodies produce GLP-1 as a hormone already; all of us are producing it, some people in higher amounts, some people in lower amounts. It is produced in our intestines. These GLP-1s then massively boost that dose of GLP-1 that we are getting. And that then tells our stomach that we are full, slows digestion. It also tells our pancreas we do not need any more, it slows all of our digestive processes down and tells us and our brain that we are full. So we do not want to eat any more. In the case of Mounjaro, so one that is used for weight loss, it also supports insulin sensitivity so it has sort of dual effect. Mounjaro in general is a bit softer on digestion; you have less side effects than you would with something like Wegovy or the Ozempic type drugs

Rob Lilley-Jones: That again leads onto my next question which is what is the difference between Mounjaro and Ozempic? Because obviously we hear them a lot, but they are different

Sophie Medlin: They are not significantly different, although the application would be different. Ozempic and Wegovy were invented for diabetes. They are very effective in diabetes with weight loss being a side effect. Mounjaro’s seen that and then it’s gone, "Actually we can increase this weight-loss side effect and make that the primary reason for using them". Mounjaro is almost a dual action therapy, whereas Ozempic and Wegovy are more single action therapy. What you will see then is Mounjaro is much more effective for weight loss than Wegovy or Ozempic

Rob Lilley-Jones: And how often can we be taking them if we are taking them or does it depend on the person?

Sophie Medlin: Normally we would start with a weekly dose and then the dose would be increased gradually. What we are finding in clinical practice is people are getting stuck on them. They have lost the weight they wanted to lose and now they are looking at, "How do we get people off these without them regaining all the lost weight?" Then some people at the end of their therapy are extending the amount of time between injections or having what they are calling a microdose for who knows how long, maybe forever, a very small dose weekly or maybe bi-weekly. The length of time of a standard treatment would be weekly, but some people are then extending that towards the end of their treatment

Rob Lilley-Jones: And if someone is having a microdose for an infinite amount of time, are there safety concerns there around those drugs being in somebody’s system constantly?

Sophie Medlin: When we look at the clinical trials that were used to prove their use, really the maximum time people were on them was between a year and a year and a half. There is not a lot of safety data on people being on them for a long, long time. They are new drugs, so they have not even been in the market for very long. It is going to be interesting to see how that plays out in the next few years

Shefalee Loth: If people are getting them via the NHS there is a cap on how long they are allowed to be prescribed them which is two years

Rob Lilley-Jones: So the headline then is weight-loss supplements, nonsense. Weight-loss jabs can be effective. If people are not getting weight-loss jabs on the NHS, if they are going out there themselves, it is something they want to look at, what should they be looking at? What are the things they should be looking out for?

Shefalee Loth: We have done a lot of research in this area and I would say probably the majority of people who are accessing these drugs are doing them privately because it is really hard; there is a lot of criteria to meet to qualify to get them on the NHS. So a lot of people are choosing to pay privately for these drugs. There are online pharmacies that will prescribe these drugs and you have to fill in an online form and meet certain criteria.

Around a year ago we did an investigation into this and it was really easy to get hold of them without meeting that criteria, either by gaming the system or tweaking your results. For research purposes I have also tried to get hold of them to see how easy it is and some places have rejected me and others have offered me the drug. It is easy to get hold of. What we would say and Sophie will certainly say is do not just use them. They are not a quick fix solution; you do have to have medical advice. The recommendations are you should be using them with dietary change as well. A really key thing is when you lose weight quickly, you lose a lot of muscle mass too. A lot of people are losing muscle mass which is not great for long-term health. When you are on these drugs you really should be exercising and doing weight-bearing exercise especially

Sophie Medlin: What I am seeing in my clinical practice is people getting stuck on them and not really knowing how to get off without regaining lost weight. There is potentially some disordered eating thoughts and behaviours in there. Also I have seen patients who are exercising but are not fuelling appropriately. They are getting away from a hunger perspective with having a couple of pieces of fruit at lunchtime maybe a very small meal later. Even if those people are still exercising rigorously, doing lots of strength-bearing exercise, what we are seeing from their scans is that their muscle mass is severely depleted. In order to maintain muscle mass we need the substrate, the protein in the diet and the stimulation, the exercise itself. If we let go of either one of those things, we are seeing people with the muscle mass of an 80-90 year old who are in their 40s because they have got on these drugs, got a bit stuck on them and not had appropriate dietary and exercise advice early doors

Rob Lilley-Jones: So we have talked about muscle loss. Are there other side effects we should be aware of as well?

Shefalee Loth: Like Sophie said they slow digestion. So actually a lot of the reported and common side effects are constipation, bloating, people feeling nauseous on them. Those are obviously unpleasant but not risky. As soon as you stop taking the medication or once you have taken them for a while they can settle down

Sophie Medlin: There are case reports and early signs of some more serious side effects coming through, but they are few and far between and also if you are being appropriately monitored hopefully by your NHS doctor if not by an online pharmacy you are at low risk of those things happening. It is when they get into the hands of the wrong people who have already pre-existing conditions and concerns, that is when those more serious side effects are something to worry about

Rob Lilley-Jones: It has been fascinating hearing more about them, about how they work, about who they might be useful for. Have either of you got anything that you want to leave anyone listening to this with, any final thoughts?

Sophie Medlin: While there are concerns at the moment about people inappropriately accessing these drugs, I do think that in the future they will be the equivalent of: if you are struggling with weight loss why would you not use them? In the same way as when glasses were invented we said, "Well if you cannot see why would you not use them?" I think they will be refined and get better. Particularly for those who have co-morbidities, diabetes, heart disease, fatty liver etc where weight loss would be so beneficial to their health, I do think we will see them much more in a way of "this is a really helpful tool in the toolkit". It is not necessarily the first tool you pick up, but it is a really helpful tool in the toolkit. And at the moment there is a lot of shame and stigma about people using them. A lot of people are using them secretly; I have heard people trying to keep them in secret compartments of their fridge away from their partners etc. But I do think in the future that will change and I do not think that people who are using them legitimately should have any shame or stigma about it

Shefalee Loth: And what about where people are getting hold of them as well?

Sophie Medlin: There is a real risk here because there are reports where people are getting them through online channels, through their hairdressers, through their beauticians etc. These are really effective medications but they are medicines. I think people should really exercise caution and not buy them from non-authorised channels. If you do want to buy these privately then do go through a proper online pharmacy; do not just buy them down the road from a friend of a friend

Rob Lilley-Jones: It is such a difficult world to navigate. You have done a great job doing so. And it was fascinating hearing more about Megan’s investigation earlier on as well. So thank you very much for being here

Shefalee Loth: Thank you

Sophie Medlin: Thank you