Since May, I’ve had a supply of Mounjaro sitting in my refrigerator. However, I’ve only used it once. The initial 2.5mg dose left me feeling nauseous and, surprisingly, even hungrier than usual, deterring me from trying it again.

Moreover, the idea of self-administering GLP-1 agonists — the category of drugs that includes weight-loss injections — began to weigh on me both mentally and emotionally. Was it really worth spending a significant amount each month on medication just to shed 10 pounds (4.5kg)?

This isn’t the first time I’ve found myself in this situation. During lockdown, I learned about Saxenda, an early injectable option for weight loss. I purchased it online, stretching the truth about my weight to qualify for it. Yet, before using it, I reconsidered. At 10st 10lb (68kg) and 5ft 4in, I realized I didn’t truly need it, nor did I have diabetes. It was merely a pursuit of vanity. I gave myself a reality check and discarded the drug.

Nonetheless, the desire to lose those extra pounds persists. Like many women, I’m dealing with a growing midsection, larger upper arms, and emerging saddle bags around my hips. Last year’s attempt at a health overhaul didn’t last, leaving me in search of more than just willpower. I need a solution akin to Mounjaro—without actually using Mounjaro.

That’s where Carb Fence comes in, a new dietary supplement from Swedish scientists that claims to slow digestion and reduce calorie absorption differently than GLP-1s, yet with similar outcomes.

Developed by Sigrid Therapeutics, Carb Fence purports to offer an advantage. While GLP-1s require dietary changes due to appetite suppression, Carb Fence suggests you can lose weight without altering your eating habits.

There’s just one problem. You have to take the stuff orally and it comes in the form of a gloopy, yoghurt-like gel containing millions of tiny particles of silica. Yes, silica – the naturally occurring mineral found in sand, clay and indeed most of the Earth’s crust.

If I’m troubled by the idea of GLP-1 injections, could I bring myself instead to swallow a product full of, well, tiny bits of rock?

Beatrice Aidin lost 5lb during two weeks of holiday, on which she says she’d normally gain at least half a stone, and found herself 3in slimmer when she measured her waist once back home

In fact, as I discover, silica is perfectly ingestible and you’re probably eating some of it for dinner this evening. It’s found naturally in foods such as green beans, brown rice and bananas and is also used as an anti-caking agent in salt and processed meats.

What’s different about the silica in Carb Fence is the subject of a patent, but, in theory, an ingredient called SiPore – the engineered silica minerals – functions as a sort of molecular sieve in the stomach, reducing the rate at which carbohydrates and fats are broken down and absorbed.

While Mounjaro and Ozempic dampen the triggers of hunger in the brain, SiPore acts as a physical barrier within the intestine – hence, presumably, the Fence in the name.

Sigrid Therapeutics describes it as a non-drug technology, and it’s recently been approved by the US Food and Drug Administration as a ‘medical food’ for the treatment of diabetes. Crucially, it claims not only to curb cravings (the most recent trial showed sugar cravings reduced by 40 per cent and snacking down by 44 per cent), reduce blood sugar spikes after a meal but also – ta-da! – lead to weight loss. Perhaps not as quickly as the jabs, but without any of the muscle or hair loss that can be caused by over-quick slimming either.

Alas, at the moment, Carb Fence is only available in a pre-launch programme in the US, though you’ll be able to buy it in the UK next year.

Britons can get something from the same manufacturer called Sigrid Glucose Stabiliser (£68 for a month’s supply), which is a dietary supplement containing SiPore, but Carb Fence is said to be six times more potent.

Which is why I wanted to try it.

So while I am on holiday in the US seeing a friend, I get my hands on some. When you buy it here, it costs $139 for a month, which is about £100 – considerably cheaper than the jabs.

To see what Carb Fence does to my blood sugar, I also have a small circular glucose monitor from a company called Lingo attached to my upper arm (£59 for two weeks, hellolingo.com), which delivers intel direct to an app on my phone.

It turns out – oh, irony – that my American friend Jennifer is on Mounjaro and has been for a year. In fact, I barely recognise her when I see her. Having struggled to lose the baby weight after three pregnancies, she has now lost 30lbs (13.6kg) and looks fantastic. It seems my holiday is going to be something of a competition.

After a spot of yoga on my first day in Connecticut, we go to a clinic so that Jennifer can have her maintenance dose jab of Mounjaro. As a nurse swiftly injects her stomach – at an eye-watering cost of $200 (£148) per shot, or roughly £600 a month – we discuss brunch venues. Of course we do. I grab the chance to weigh myself: still 68kg (10st 10lbs) which is 10lbs more than I’d like to be. Nestled in my handbag lies the first of my Carb Fence sachets.

I’m excited to start taking them, but I do have one worry. I’m on holiday, staying in someone else’s home, doing things like yoga. I have to hope any gastrointestinal sieving will be gentle because a dodgy tummy would be mortifying.

The way Carb Fence works is that you take it after each meal. So that’s three sachets a day, containing roughly two to three tablespoons of gel. I’ve committed to three weeks of Carb Fence, but it can be taken for a three-month period.

For brunch we have bagels, smoked salmon and cream cheese. Jet lag has made me ravenous. I tear into my food and then pause to knock back my Carb Fence with a glass of water. To my relief the liquid tastes neutral, and the texture is like a thick smoothie. It goes down in seconds.

I repeat it all at dinner, and feel… fine. I’m no different at all, in fact – just excited and curious to see whether it will work. The next day, there’s no difference to my hunger levels either, but I’m not sure if there’s supposed to be. I am, however, suffering another digestive consequence of jet lag – constipation.

After a lunch of salad, which Jennifer daintily picks at (and I supplement with bread and butter) we go for a long walk, and when I return to her house, there is a dramatic reversal of the stomach issue and I find myself stuck on the loo for some time. Is this the Carb Fence at work?

All returns to approximate working order the next day, but by day four of my holiday – and Carb Fence experiment – I have definitely noticed that I’m eating less. Of course I’m with someone who now eats like a bird thanks to Mounjaro, but it’s not just that I’m matching my friend bite for tiny bite. I simply don’t have as much appetite.

I come to the conclusion that the bathroom issues were caused solely by the long flight, and thankfully don’t suffer them again.

On holiday in the US, I usually have a very forgiving attitude to dietary sins. The food in this part of the States is good in terms of quality and ingredients, but the portions are insane. A Caesar salad comes in such a huge heap, it could easily amount to 3,000 calories. Normally, I wouldn’t mind this at all – in fact, I’d let myself eat all the burgers, pancakes and ice cream I want, too – but I would try to deal with the holiday excess when I got home, restricting my diet until I was back where I started. Only 10lbs overweight rather than 20.

Now? Though I’m loving the aroma of all the diners and fast food joints, I don’t actually want all that fat and carb-heavy richness. The cravings are gone. This must be the SiPore.

All those silica particles in the gut are trapping digestive enzymes, slowing down the transit of food and making me feel fuller for longer. It’s not that I don’t have any so-called ‘food noise’ – I still do – but that I don’t have the desire to act on it. Having said that, one of the attractions of Carb Fence to people like me with no willpower is that you’re told you can eat what you like on it.

Even cheeseburgers.

Carb Fence – from the company Sigrid Therapeutics – says you can lose weight while eating exactly the same things you always did

(The SiPore manufacturers do advise that, at each meal, you eat protein first and vegetables second, which has the effect of filling you up more quickly and balancing glucose.)

I’m afraid I am now prey to another noise, however. Seven days in, wind is a definite problem, and I blush at the thought of the person behind me in yoga. A trip to the pharmacy means tablets called Gas-X join the Carb Fence in my handbag.

My Lingo monitor shows that I am hitting my blood glucose target of less than 5.5mmol/L, from a slightly elevated start of 6 (a typical healthy value is 3.9 to 5.5). Before I started with Carb Fence, my blood sugar would shoot up when I ate something like pizza, but I’m just not craving that sort of carb-heavy meal any more. I start to think it’s really going to work. My clothes feel looser, including my cotton shorts. The Holy Grail of all diets and weight-loss regimes is stomach fat loss – could I have discovered it?

One week down and it’s time to weigh in. With heart in mouth, I step on Jennifer’s scales. Ten stone 6 lbs (66kg)! I am down almost 4lbs. This is a great result.

Though I’m not eating complete rubbish, I’m eating what I like when I’m hungry, and in portion sizes that more than fill me up. Which is exactly what the makers of Carb Fence tell us to do. Later I see another friend, Sarah, who has lost 35lb on jabs, but tells me she has to force herself to eat because she has lost the biological hunger cue and forgets meals.

At times she has been so lacking in fuel, she has lost concentration at work and felt faint. She’s very happy with the results, but also tells me she felt nausea ‘like permanent morning sickness’ for the first few weeks. I don’t tell her about the pens in my fridge, but I am glad I didn’t persevere with them.

That evening we hit the town and I make the unwise decision to sip Sidecar cocktails all night, leaving me tired and hungover hungry the next day. I don’t take Carb Fence with the booze and my blood sugar levels are through the roof too, reaching 8mmol/L, which triggers a telling off from my Lingo monitor.

Despite that, I go for a full-on American breakfast to cure the headache: pancakes, bacon, maple syrup – with a sachet of silica of course.

Normally, I’d have polished off the whole, US-sized serving, but I shock myself by stopping halfway through, defeated. This is the ultimate comfort food, and yet I feel horribly uncomfortable. Bloated and bilious.

I throw myself in Long Island Sound, and the cool water makes me feel more human again. I refuse to beat myself up for either the Sidecars or the pancakes, but I know that neither of them really agreed with me.

The next day I’m back to myself and even start to feel rather smug. I am becoming a Lingo app bore, telling anyone who will listen that my glucose levels don’t spike and then crash after eating but stay obediently level instead.

I hadn’t expected to feel this evenness on an emotional level too, but I do. Yes, I’m on a stress-free holiday, but my mood feels almost unnaturally stable and upbeat – and I suddenly understand how much my frame of mind is affected by sugar. It’s not just the waistline, but my mental state that suffers when I indulge my sweet tooth with a pack of Fruit Pastilles.

The day before I leave, I try to cram in all the activities we haven’t yet done – I go sailing, hit the department store Target, and realise I haven’t ordered my usual menu favourites either.

I haven’t had a corndog or mac and cheese or key lime pie. The truth is, I haven’t really thought about them, and that feels a bit strange: a holiday without food at its heart.

It’s great for my motivation, however: I feel empowered by the fact I’m not distracted by foods I know aren’t good for me.

It’s time to do another weigh-in before I head off to the airport. I blame the cocktail night for the fact I’ve only lost another pound, but altogether it’s still a fantastic result.

Over two weeks of holiday during which I’d normally gain at least half a stone, I’ve lost 5lb.

Back in London I measure my waist – I’m 3in slimmer.

I haven’t felt deprived, my blood sugar is more stable and I’ve had a brilliant time. I carry on the Carb Fence in London for another week and lose another 2lb, while still eating essentially what I want. Now I’m half a stone down in three weeks. My face hasn’t sagged, my hair hasn’t fallen out. I’m just slimmer.

Of course, I’m now off the Carb Fence, and who knows how that will go.

But I’m even more sure I’ll never use the Mounjaro. If SiPore really is a means of dropping weight without needles, drugs or willpower, then it’s a life-changing discovery indeed.