The September edition of Which? has an article about weight loss injections - I think it's a balanced article which covers the pro's and con's fairly well:
The Ozempic effect
A new wave of weight-loss drugs is available to some on the NHS and to many more privately. They do work – but with caveats. Shefalee Loth and Sara Spary explain what you need to know and expose a concerning lack of rigour from some pharmacies
Ozempic, Wegovy, semaglutide and Mounjaro have quickly become familiar names to many of us. Two of these, Wegovy and Mounjaro, have been approved as weight-loss aids in the past year and have rarely been out of the headlines since.
Ozempic is the name that’s stuck in the popular imagination but it's actually the brand name for the diabetes-approved version of semaglutide. Ozempic isn't registered for and shouldn’t be used for weight loss as the doses can be different.
These weight-loss drugs, selfinjected weekly into your thigh, abdomen or upper arm, slow digestion and increase the time it takes for food to leave your stomach. They alter brain signals to help you feel fuller for longer, reducing appetite and increasing insulin to regulate blood glucose levels.
They were originally developed as a treatment for type 2 diabetes but it was discovered they could also help with weight loss, lowering people’s risk of many obesity-related diseases, such as heart disease and diabetes.
The actual drugs are semaglutide and tirzepatide, and the brand names they’re sold under for weight loss are Wegovy and Mounjaro, respectively.
Studies show that people taking Wegovy and Mounjaro lose weight within two to four weeks of starting the drug. In trials, people have lost up to 22% of their
body weight.
Tip of the iceberg
Professor Giles Yeo, an obesity geneticist at the University of Cambridge, says the drugs currently available are the tip of the iceberg.
He says: ‘New drugs are being tested in trials that target multiple receptors. These could result in greater and quicker weight loss, fewer doses needed – monthly instead of weekly, say – and fewer side effects.’
As well as weight loss, these medicines also reduce blood pressure, the risk of cardiovascular disease and several cancers, so it’s not surprising that they’re being hailed as wonder drugs that could save the NHS a lot of money in the long run.
However, the benefits only last while you’re taking the drugs. Once you stop, your appetite returns to normal in a week and most people will put the weight back on.
They can have unpleasant side effects too, the most common being nausea and vomiting, heartburn, constipation, diarrhoea, stomach pains and headaches, which affect around 10% of people taking them, although these tend to be transient.
More severe, but rarer, side effects reported include pancreatitis, kidney problems and thyroid tumours.
Who’s eligible?
Wegovy is available via the NHS for some and it’s expected Mounjaro will be shortly too. However, there are strict criteria to meet and limits to what is on offer.
To qualify you must have a condition such as hypertension or cardiovascular disease and a body mass index (BMI) of 35kg/m2 or above. BMI is calculated by dividing an adult's weight in kg by their height in metres squared (kg/m2).
People with a BMI of 30, who meet the criteria for referral to a specialist weight management service and who have tried unsuccessfully to lose weight, are also eligible. So too are Black, Asian, Chinese and Middle Eastern people at a lower BMI threshold (minimum 27.5) due to increased risk of some diseases.
In July 2024, semaglutide was approved to be used for people with established cardiovascular disease and a BMI of 27 or more to prevent heart attacks and strokes.
The jabs are also available privately with a lesser BMI of 30. Patients referring themselves via online pharmacies can get Wegovy and Mounjaro from around £150 a month, up to around £300 a month for the maximum dose.
Ingrid, 55, explains how her private Mounjaro prescription has helped her lose a stone in eight weeks
I have osteoarthritis in my knee and my consultant recommended I lose weight. I tried using Orlistat (a prescription weight-loss tablet that stops the fat in your food being absorbed). After six months I’d not lost a pound, so he suggested I try one of these weight -loss drugs and wrote to my GP.
Unfortunately, my GP didn’t refer me, but by this point I’d done a lot of research and decided to pay for a private prescription. I used Lloyds Pharmacy as I get my other medications from there.
I filled out a form online and sent in a series of full-length photos in front of a mirror with a weighing scale in the picture and a form of ID. Once I passed the screening process, I was sent my first month’s dose of Mounjaro.
I’ve been lucky as I only had stomach cramps on the first day, otherwise I’ve had no side effects, even when I increased my dose.
My diet has totally changed. I now eat only a fraction of what I used to, and I just don’t get hungry. I still enjoy food – my portion sizes are just smaller.
In eight weeks I’ve been taking Mounjaro I’ve gone from 96kg (15 stone) to 89kg (14 stone) and my knee feels better. My target weight is around 78kg (12 stone). This has been a miracle for me.
People taking the drugs on an NHS prescription are supported with nutrition and exercise advice, but this isn’t always the case for those on private prescriptions.
Prof Yeo has concerns about this: ‘These drugs shouldn’t be used in isolation. When people drastically reduce their dietary intake, as they do on these drugs, there is a risk of fibre, protein and micronutrient deficiencies', he said.
He thinks it’s essential people are supported with nutrition and physical exercise advice: ‘When you lose weight quickly you lose 50% fat and 50% muscle mass. No one signs up to lose muscle and people need to counterbalance this with exercise and resistance training, especially those who are over 40.’
Jabs forever?
Under current guidelines, Wegovy can only be prescribed by the NHS for up to two years. But given that patients are likely to put on weight once they stop, Prof Yeo thinks this will change and patients will be kept on some form of ‘maintenance dose’. There is no such limit for patients buying privately.
Prof Yeo says he’s uncomfortable with people using weight-loss drugs who don’t really need them (ie those who just want to lose a few pounds). He sees a need for tightening regulation on how people access them.
Vicky Price, A&E consultant and president-elect of the Society for Acute Medicine, has dealt with the consequences of people taking them that don’t need to or who take them irresponsibly. She has treated increasing numbers in A&E, including those with ketoacidosis and pancreatitis – conditions that can be fatal if left untreated.
Dr Price says: ‘The majority of people I’ve seen have been of a normal body weight that would under no circumstances fit the required body weight for these medications.
‘We are seeing people who have lied [about their weight] to online pharmacies, but we’re also seeing people who are getting these drugs from less reputable sources, such as from beauticians.’
When she prescribes medication she has access to a person’s medical history, and takes it into account. She thinks the current system of relying on patient knowledge and honesty about their health is inadequate.
‘We need better regulation, it’s not safe – it’s easy to get these medications. What worries me is the reasons why people are doing this – why are young women getting them? Are they feeling pressured to lose weight [for cosmetic reasons]? This is not what these drugs were designed for.’
Her concerns were echoed by eating disorder charity, Beat. Its clinical advice coordinator, Umairah Malik, criticised the fact that weight-loss injections are readily available without ‘comprehensive eating disorder screening’ or in-person consultation.
Prof Yeo agrees that in-person prescribing should be required, and he cautions against a future where weight-loss drugs are widely used in isolation. He said it’s important the government still works to improve our food system and environment so that people can access affordable, healthy food. Ultimately prevention is better than cure.'