What to know about accessing weight-loss jabs privately

Weight-loss injections such as Wegovy and Mounjaro are available to buy privately, but some experts have concerns about the support available and potential for misuse
Stylised editorial image of a Russian doll injecting itself with a weight-loss jab

Weight-loss jabs have rarely been out of the headlines in the past year or so and, as such, interest in the drugs is high - and supplies are stretched. 

But some people are taking them who don't need to and are putting their health at risk. And some online pharmacies aren't carrying out the necessary checks.

NHS qualifying criteria mean only a limited number of people can access them via the NHS, but they are also available to buy privately via licensed pharmacies or private GPs.

However, this comes at a considerable monthly cost, and there are concerns that there aren't enough checks in place to ensure the drugs aren't misused.


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Why are the jabs so in demand?

Image of Wegovy pen

Weight-loss drugs such as Wegovy are self-injected weekly, and work by slowing digestion and increasing the time it takes for food to leave your stomach, altering brain signals to help you feel fuller for longer and reduce appetite.

Originally developed as a treatment for diabetes, it was discovered they could help with weight loss too, and as a result lower people’s risk of many obesity-related diseases, such as heart disease, diabetes and more.

The actual drugs are semaglutide and tirzepatide, and the brand names they’re sold under for weight loss are Wegovy and Mounjaro, respectively. 

While Ozempic is the name that’s stuck in the popular imagination, it's actually the diabetes-approved version of semaglutide and has a different dose.  

Professor Giles Yeo, an obesity geneticist, says that the drugs currently available are the tip of the iceberg. He told us: ‘New drugs are being tested in trials that target multiple receptors. These could result in greater and quicker weight loss, fewer doses needed (say monthly instead of weekly) and fewer side effects.’

But the benefits only last while you’re taking the drugs. Once you stop, appetite returns to normal in a week and some 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 the side effects tend to be transient. 

More severe, but rarer, side effects reported include pancreatitis, kidney problems and thyroid tumours. 

Accessing weight-loss jabs

An image of a Mounjaro pen

Wegovy is available via the NHS for some patients and it’s expected that Mounjaro will be shortly too. However, you have to meet certain criteria to be eligible and there are limits to what is on offer.

Currently, you must have a weight-related condition such as high blood pressure, cardiovascular disease or diabetes, and a Body Mass Index (BMI) of 35kg/m2 or more. Alternatively you need to have a weight-related condition, a BMI of 30kg/m2 or more, qualify for referral to a specialist weight management service (SWMS) and have already tried to lose weight.

People from Black, Asian, Chinese and Middle Eastern communities are eligible at a lower BMI (27.5kg/m2) because they have an increased risk of weight-related disease at lower body weights. 

The jabs are also available privately. 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.

The criteria for private prescriptions are less strict - you need to have a BMI of 30kg/m2 or more.

But, where NHS patients are supported with nutrition and exercise advice, this isn’t always the case for those on private prescriptions (although you are meant to be given advice and support).

Professor Yeo has concerns about this, telling us: ‘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 thinks it's essential people are supported with nutrition and physical exercise advice, saying: ‘when you lose weight quickly you lose 50% fat and 50% muscle mass. No one signs up to lose muscle, and people need to offset this with exercise and resistance training, especially people over 40.’

Yeo also cautions against a future where weight-loss drugs are widely used in isolation, adding: ‘it’s important that 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’.


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Patient experiences of weight-loss drugs

We asked Which? members who'd used these drugs to tell us about their experiences. 

Which? member Steve told us: 'I was referred to a specialist weight management service by my heart consultant and started taking Wegovy in November 2023'.

Since then he's lost 30kg and his eating habits have changed drastically. He told us that he no longer likes takeaways and finds them too heavy and greasy.

Image of a small portion healthy meal

Ingrid, another Which? member, got a private prescription for Wegovy. She told us: 'I have osteoarthritis in my knee, and my consultant recommended I lose weight and suggested Wegovy. I went to my GP but they wouldn't refer me to a specialist weight management service so I decided to pay for it privately.' 

She's been taking Mounjaro for a couple of months and is happy with the results - she said she's lost 8kg so far and her knee feels better.

As for side effects, Which? members who've used these drugs told us that they experienced some side effects when they started taking them - and when they increased their doses - but that these tended to pass within a few days. 

Some are using weight-loss drugs inappropriately

While for some people who have struggled with serious weight-related issues, the drugs can have a really positive impact, there are concerns about people using them inappropriately. 

Dr Vicky Price, A&E consultant and president-elect of the Society for Acute Medicine, told us she has dealt with the consequences of people who don't need these drugs taking them to get 'beach body ready' or taking them irresponsibly. 

She said she's treated increasing numbers of patients in A&E with issues caused by this, including people with ketoacidosis and pancreatitis, conditions that can be fatal if not treated.

She said 'The majority of people I have seen have been of a normal weight that under no circumstances meets the required BMI for these medications. We are seeing people who have lied about their weight to online pharmacies and people who are getting these drugs from beauticians and other less reputable sources''

An A&E department

Her concerns were echoed by the eating disorder charity, BEAT.  Umairah Malik, clinical advice coordinator for the charity, said the virtual consultation model (for private prescriptions of weight-loss jabs) was dangerous for people with eating disorders and those at risk of a disorder. She criticised the fact that weight-loss injections are readily available, in her view, without ‘comprehensive eating disorder screening’ or in-person consultation.

Dr Price added that 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 honesty, and patient knowledge about their health, is ‘absolutely not’ adequate.

‘We need better regulation, it’s not safe - it’s very easy to get these medications. And 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.’

Demand for these drugs, and people getting similar ones, such as Ozempic (a diabetes drug) off-label, has also caused shortages for people who really need them.


Read our guide on everything you need to know about weight loss drugs


Are online pharmacies carrying out sufficient checks?

A person standing on weighing scales

Research by Which? and other media organisations has shown how easily people can get these medications under false pretences via online pharmacies. 

Some are more stringent in their screening processes than others. All rely on customers giving honest answers to their medical questions and being honest about their weight. But the process is open to misuse. 

A Which? researcher used a false name, false GP details and a false weight to test the processes of seven online pharmacies that supply weight-loss drugs.

Only Asda Online Doctor and Superdrug refused our prescription outright. We were able to go through the consultation process with Boots and Pharmacy2U, but couldn't submit the request as each required photo ID upfront. Numan and Simple Online Pharmacy approved our request but didn't post the drugs to us as our fake name failed their ID checks.

However, ZavaMed posted Wegovy to us without verifying our ID. When we queried this, ZavaMed responded that it was incorrect to say it hadn't carried out ID verification and that it relies on the integrity and honesty of patients. It said it has safeguarding mechanisms in place to stop individuals bypassing its systems and any misrepresentation of health information to obtain treatment was a breach of its terms. 

Apart from Numan and Simple Online Pharmacy, all the other online pharmacies asked for photos of the researcher in tight clothing as a safeguard. But this isn't a failsafe way to judge a person's BMI, as our results show. 

Asda Online Doctor, Superdrug and ZavaMed also asked for a photo of the researcher's feet standing on a set of scales. But gaming the minimum weight requirement was easy with the addition of a heavy backpack.

Simple Online Pharmacy has since added a photograph requirement. 

Boots and Superdrug told us they have safeguarding protocols in place. Asda Online Doctor, Numan and Pharmacy2U didn't respond to our request for comment. In addition to its comments above, Zavamed added that:  'As a reputable provider, we seek to continually review and improve our services to enhance patient safety whilst still providing a robust, fair and accessible service for patients in need.' 

While there are clear benefits to these drugs for some groups, the experts we spoke to saw a need for tightening of regulation around how people access these drugs, and suggested that at a minimum, in-person prescribing should be required.

Black market supplies pose serious risk to patients

It's important to buy these drugs - and any medications - from trusted, authorised sources. But such is the demand that people are risking their health by seeking out alternatives.

In October 2023, the Medicines and Healthcare Regulatory Agency (MHRA) issued a warning about fake versions of semaglutide pens available online where the contents didn't match the ingredients listed on the label. And in July 2024 it was reported that people had been hospitalised after buying 'fake Ozempic' online. Batches of counterfeit Ozempic and semaglutide have also been seized by UK authorities.  

Dr Alison Cave, chief safety officer for the Medicines and Healthcare products Regulatory Agency (MHRA), told us: 'Semaglutide and liraglutide are prescription-only medicines and should only be taken following a consultation with a healthcare professional.

'Buying prescription-only medicines without a prescription, from illegally trading suppliers, significantly increases the risk of receiving something which is either fake or not licensed for use in the UK. 

'Products purchased in this way do not meet our strict quality and safety standards, and taking such medicines may put your health at significant risk.

'If you suspect that you’ve had a side effect to semaglutide, liraglutide or any other medicine, or suspect it’s not a genuine product, you can report it to our Yellow Card scheme.'


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