GLP-1 for weight loss

GLP-1 agonists are a type of medication that mimics the way the natural hormone, GLP-1, works. They manage blood sugar and stabilise hunger to treat obesity and type 2 diabetes.

GLP-1 agonists are self-injectable medications, supplied in an injection pen. You can inject them yourself into designated areas of the body (abdomen, thighs, or upper arms) on a weekly or daily basis, depending on the type you have been prescribed.

GLP-1 agonists are also referred to as:

• GLP-1 receptor agonists
• incretin mimetics
• GLP-1 analogs

Examples of GLP-1 agonists to treat obesity include:

• Wegovy (semaglutide)
• Mounjaro (tirzepatide)
• Saxenda (liraglutide)

You may have also heard of Ozempic. However, Ozempic is not available for weight loss and is only licensed for people with type 2 diabetes. Wegovy contains the same active ingredient as Ozempic, but is available to help you lose weight.

No matter which GLP-1 agonist you use, it will be most effective when used alongside lifestyle changes such as a healthy diet and regular exercise.

GLP-1 receptor agonists work by mimicking the effects of 1 or 2 naturally produced digestive hormones – glucagon-like peptide -1 and glucose-dependent insulinotropic polypeptide (GIP). Wegovy and Saxenda mimic GLP-1 while Mounjaro mimics both GLP-1 and GIP.

Weight loss injections work by:

1. Slowing down the food travelling through your digestive system so you feel more full.
2. Suppressing your appetite so you can reduce your calories without feeling hungry.
3. Increasing the amount of insulin your body makes to control blood sugar levels. This is more helpful for diabetes but can also help with weight management as unmanaged blood sugar can cause cravings.
4. Reducing the amount of sugar your liver makes. Most sugars are stored as fat, so this works for both diabetes and weight management.

GLP-1 agonists may also have benefits for heart health, with research suggesting that they can reduce the risk of strokes, heart attacks, and death caused by cardiovascular disease by 20% compared to a placebo.

GLP-1 receptor agonists act like the naturally produced hormone, GLP-1. This means that the man-made active ingredient – semaglutide, tirzepatide, or liraglutide – binds to the same receptors.

Normally when you eat, this triggers the release of GLP-1 and signals are sent to the brain telling it you are full, so you stop eating. However, the GLP-1 hormone has a very short half life, meaning it doesn’t last very long in your system. Active ingredients like semaglutide, tirzepatide, or liraglutide can make your body think that GLP-1 levels are lasting longer than they usually would.

Therefore, using GLP-1 agonists has the same effect and so signals to the brain that you are full, which helps you to reduce the amount of food you eat, and promotes weight loss because you are less likely to snack or overeat.

The effectiveness of GLP-1 agonists for weight loss will depend on the brand or active ingredient. However, tirzepatide (Mounjaro), Wegovy (semaglutide), and liraglutide (Saxenda) have all been shown to effectively support weight loss.

Clinical trials involving Mounjaro have shown that people can lose an average 22.5% of their starting body weight by reaching the maximum maintenance dose of 15mg per week after 72 weeks.

The active ingredient in Wegovy can help people lose up to 21% of their initial body weight when they are taking the highest 7.2mg maintenance dose after 72 weeks.

For Saxenda/ Nevolat (or generic liraglutide) users, the average weight loss on the maximum maintenance dose is 8% over 56 weeks.

Currently, Wegovy, Mounjaro and Nevolat (generic liraglutide) are available for weight loss from Asda Online Doctor.

Ozempic, Rybelsus, Victoza, and Trulicity are only licensed for type 2 diabetes in the UK and are not currently available from us.

GLP-1 medication for weight loss

In the UK, the following GLP-1 agonist drugs are available for weight loss:

• Mounjaro
• Wegovy
• Nevolat (the generic version of liraglutide, previously under the brand name Saxenda)

The comparison table below includes more information on the active ingredients, how they work, how often they are used, and the effectiveness of each:

GLP-1 medication for diabetes

In the UK, the following GLP-1 drugs are available for diabetes:

• Ozempic – a weekly injectable treatment containing semaglutide in lower doses than Wegovy
• Rybelsus – oral tablets containing semaglutide
• Trulicity – a weekly injectable treatment containing dulagutide
• Victoza – a daily injectable treatment containing liraglutide

Other forms of GLP-1

Although GLP-1 medications are most commonly associated with injections, there are also GLP-1 tablets available. You may also have heard of GLP-1 patches and oral drops.

GLP-1 tablets

Just like injections, GLP-1 tablets work by mimicking the effects of the naturally produced GLP-1 hormone to control blood sugar, slow digestion, and reduce appetite, except they are available in tablets that you can swallow and are usually taken every day rather than weekly.

Rybelsus is an example of a GLP-1 tablet that contains semaglutide, the same active ingredient as Wegovy and Ozempic, but it is not licensed for weight loss in the UK. There’s also a Wegovy tablet in the US, which is not currently available in the UK but may be available soon.

Orforglipron is a GLP-1 pill that’s currently in phase 3 clinical trials and has been shown to help obese and overweight people with type 2 diabetes lose 10.5% of their body weight after 72 weeks. These pills could offer alternatives to weight loss injections, particularly for people who may not have gotten the results they were expecting or who do not like needles.

GLP-1 patches

GLP-1 patches are over-the-counter adhesive patches that stick to your skin. They are marketed for weight loss and claim to increase natural GLP-1 production, but they do not contain any actual GLP-1 medication. Instead, they often contain vitamins or herbs, such as berberine, green tea extract, or Garcinia Cambogia, but there is no scientific evidence that shows these patches work for weight loss.

Although these so-called GLP-1 patches are not medications, they can cause side effects. However, it’s not exactly clear what side effects they can cause, as they have not been rigorously tested, like weight loss injections and pills, but could include:

• feeling or being sick
• diarrhoea
• heartburn
• skin reactions

GLP-1 oral drops

Similar to GLP-1 patches, oral drops are often marketed for weight loss, but there is no scientific evidence that they work. Despite having GLP-1 in their name, these drops are unlikely to contain any GLP-1 medications, and some have been shown to be a saline (salt water) solution.

In the UK, there are no GLP-1 oral solutions approved for weight loss.

Even though GLP-1 receptor agonists can support weight loss and help you control blood sugar levels, they can also cause side effects. Some of the common side effects associated with these medications include:

• feeling sick (nausea)
• being sick (vomiting)
• constipation
• stomach pain
• weakness or tiredness
• headache
• dizziness
• gas
• bloating
• mood changes
• heartburn or indigestion
• injection site reactions

Some of the less common but severe side effects include:

• allergic reactions (difficulty breathing and swallowing, wheezing, face or lip swelling, dizziness, and body rash)
• hip fractures
• inflamed pancreas (pancreatitis, which may cause severe and persistent stomach pain or vomiting)
• kidney or bladder stones

Most mild side effects will clear up on their own within a few months, once your body has got used to the new medication. However, if you are concerned or are experiencing side effects that are difficult to manage, you should speak to your doctor.

GLP-1 agonists are not suitable for everyone and there are specific criteria you will need to meet to get a prescription. In most cases, GLP-1 receptor agonists will be prescribed for weight loss if either of the following apply to you:

• a BMI of 30 or more
• a BMI over 27 and you have a weight-related health condition, such as high blood pressure, high blood fat levels, or obstructive sleep apnoea

GLP-1 agonists for weight loss will not be prescribed to you if you are not overweight or obese.

GLP-1 agonist medications may be available on the NHS or via a private prescription from an online doctor service such as Asda Online Doctor.

You can request Wegovy, Mounjaro, or Nevolat from Asda Online Doctor quickly and easily. Simply:

1. Complete a short set of medical questions that will be reviewed by one of our doctors.
2. Create a free patient account, if you do not already have one, and make payment. Then, choose the delivery options that suit you.
3. Our doctors will check your medical questionnaire and prescribe your chosen weight loss injection, if suitable. If it is not, they may be able to offer an alternative weight loss treatment.
4. Your medication will be dispatched and sent to your chosen address in discreet packaging.
5. We’ll also provide a weight loss package to help you get started, containing information on how to follow a diet and exercise plan.

When will GLP-1 tablets be available to buy in the UK?

GLP-1 tablets, like orforglipron, could become available for weight loss in 2026 after it has been approved by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA). Currently, orforglipron has not been approved for use in the UK, and there is no confirmed date of when it may be available.

In the meantime, Rybelsus, a GLP-1 pill containing semaglutide, is approved for use in the UK for the management of type 2 diabetes, not for weight loss.

Can you buy GLP-1 medication over the counter?

No, GLP-1 medications like Wegovy, Mounjaro, and Nevolat are not available over the counter, so you must have a prescription from a doctor before you can get them. That’s because they require a doctor to assess if they are safe for you to use and monitor any side effects you might get.

Yes, you can switch between GLP-1 medications. We have a service that makes switching your weight loss injection simple and safe. Switching safely means leaving 7 days between treatments. So, if you are switching from Mounjaro to Wegovy and stop taking Mounjaro with our service, you’ll start Wegovy after a one-week break. If you are switching from Wegovy to Mounjaro you’ll also be able to stop Wegovy, wait for just 7 days and then start your first dose of Mounjaro.

If you’re new to Asda Online Doctor, all you need to do is request treatment for the GLP-1 you would like to switch to and one of our doctors will check your eligibility, personal health and medical history to ensure it is safe and suitable for you to take.

Already with us? The switching process is even more simple. Just submit a health questionnaire via your patient account which will inform us that you would like to switch. You will likely be eligible to switch to a different GLP-1 medication if you are already getting treatment from us; our doctors will always check if the medication you want to switch to is right for you.