What non-prescription weight loss drugs are available in the UK?

Ready to take the next step? See if you're eligible for expert-led weight loss support.

Check your eligibility

Can you purchase non-prescription weight loss drugs over the counter? Read our guide to know your options.

Can you purchase non-prescription weight loss drugs over the counter? Read our guide to know your options.

Here at SemaPen, we specialise in guided weight loss programmes for people living with obesity. These programmes use the prescription weight loss drugs Wegovy and Mounjaro.


These drugs are only available on prescription because it's really important that doctors check whether they're right for you. That's why we offer an online consultation for new patients – it's so we can ask questions to determine whether treatment is safe and appropriate.


But do you have to get a prescription? Are there options available over the counter from UK pharmacies?


Yes. You can get one weight loss medication over the counter, as well as several types of weight loss supplements.


In this article, we look at these options, how they work and how effective they can be.


What over-the-counter weight loss drugs are available in the UK?


Currently, there's only one non-prescription weight loss drug approved for use in the UK. It uses the active ingredient orlistat and is available under the brand name Alli.


You can buy Alli at many online and high-street pharmacies in tablet form. These tablets contain 60mg of orlistat.


Higher-strength (120mg) capsules are also available under names like Orlistat and Xenical. However, you can only get these with a prescription from a doctor.


How does Alli work?


Alli is part of a family of drugs called lipase inhibitors. These drugs work by stopping your digestive system from absorbing all the fat you consume.


They do this by binding to enzymes called lipases, which help the body break down fat. Alli stops these lipases working as well as they should – that's why it's called a 'lipase inhibitor'.


The intended result is that your body takes in less fat and you lose weight. The excess fat that would have been absorbed comes out in your stool when you go to the toilet.


How do you take Alli?


Alli is taken orally (as a tablet) three times per day. It should be taken with food – either before,

during or within an hour of a meal.


How effective is Alli?


Alli is a moderately effective weight loss treatment. If you take it alongside a calorie-controlled diet and exercise, you'll likely lose a little more weight than you would with diet and exercise alone.


One of the best-known studies of orlistat was published in 2004. The study saw 3,305 participants treated with either


a course of 120mg orlistat tablets, or

a placebo (a harmless substance with no medical effects).


The participants also undertook lifestyle changes to help improve weight loss.


After four years of treatment, the average weight loss for the participants taking orlistat was 5.8kg. The average for the placebo group was 3kg.¹ This proves the drug is more effective than diet and exercise alone.

A woman is standing on a scale in front of a couch.

However, the results are not quite so impressive when compared to prescription weight loss drugs like Mounjaro and Wegovy.


Take the main trial looking at Wegovy for weight loss. In this trial, participants on Wegovy lost an average of 15.3kg over 68 weeks, compared to 2.6kg in the placebo group.²


Participants in Mounjaro's most famous clinical trial saw even greater average weight loss – 23.6kg for patients on a 15mg dose, versus 2.4kg with the placebo.


Don't get us wrong. If diet and exercise aren't producing the results you want, Alli can help give your weight loss journey a useful little boost. However, it won't achieve quite the same results as a prescription medication like Wegovy or Mounjaro.


Bear in mind, too, that the orlistat clinical trial looked at patients on a 120mg dose. Alli is only available as an over-the-counter weight loss drug in a 60mg dose.


Other types of over-the-counter weight loss treatments


Alli is the only non-prescription weight loss drug available in the UK. You might see other tablets and treatments on pharmacy shelves. However, these are weight loss supplements, not drugs.


Drugs and food supplements are covered by different rules and regulations. While supplements must be safe to consume, they're not held to the same standards as medicines when it comes to things like advertising and effectiveness.


That's not to say that all weight loss supplements are ineffective. One meta-analysis (study of studies) looking at green tea extract, for instance, found that it likely causes a small amount of weight loss in adults.⁴


However, it's difficult to cover weight loss supplements in much detail. That's because there are so many of them and the evidence supporting their usefulness is often inconsistent.


If you choose to take a weight loss supplement, the best advice we can give is to do your research. Weigh up the claims on the packaging with the clinical evidence available – and don't go in expecting miracles.


Can you get GLP-1 drugs for weight loss over the counter?


No. GLP-1 drugs like Mounjaro and Wegovy are only available on prescription in the UK.


These types of drugs have strict eligibility criteria. In other words, you must meet certain conditions before the drug can be prescribed to you. For instance, you must


be living with obesity (have a BMI of 30 or more) or

have a BMI of 27 or more, along with a serious medical condition related to obesity, and

have tried and failed to lose weight with diet and exercise.


If these conditions apply to you and you want to try Mounjaro or Wegovy, speak to your doctor or take our online consultation.


Designed by SemaPen's UK doctors, the consultation covers all the key points we need to know to decide whether you're eligible for treatment. This means we can give you an instant response.


Sources


1. Torgerson, J.S. et al. (2004) "XENical in the Prevention of Diabetes in Obese Subjects (XENDOS) Study: A randomized study of orlistat as an adjunct to lifestyle changes for the prevention of type 2 diabetes in obese patients" 27(1) https://doi.org/10.2337/diacare.27.1.155


2. Wilding, J.P.H. et al. (2021) "Once-weekly semaglutide in adults with overweight or obesity" New England Journal of Medicine, 384(11) https://doi.org/10.1056/NEJMoa2032183


3. Jastreboff, A.M. et al. (2022) "Tirzepatide Once Weekly for the Treatment of Obesity" New England Journal of Medicine, 387(3) https://doi.org/10.1056/NEJMoa2206038


4. Jurgens, T.M. et al. (2012) "Green tea for weight loss and weight maintenance in overweight or obese adults" The Cochrane database of systematic reviews, 12(12) https://doi.org/10.1002/14651858.CD008650.pub2

  • Average 15-21% weight loss*
  • Tailored programmes built by real experts
  • Targeted support to make success feel simpler
  • Unique app with weight loss tools and lessons

Your journey starts here

Start your personalised weight loss plan in minutes.

1

Start your online consultation

2

Get approved by our clinical team

3

Begin your programme

Get started
Get the key facts about carbohydrates. Learn about their role in weight management
by Simon Edward 10 April 2026
Get the key facts about carbohydrates. Learn about their role in weight management and where they fit into a balanced diet.
Just starting out on your journey to sustainable health? Explore simple, evidence-based weight loss
by Simon Edward 6 April 2026
Just starting out on your journey to sustainable health? Explore simple, evidence-based weight loss tips for beginners.
Taking Mounjaro weight loss injections might affect how warfarin tablets are absorbed into the body.
by Simon Edward 31 March 2026
Taking Mounjaro weight loss injections might affect how warfarin tablets are absorbed into the body. Learn what this means for you as a patient.
Compounded semaglutide is an unlicensed version of the active ingredient found in Wegovy.
by Simon Edward 31 March 2026
Compounded semaglutide is an unlicensed version of the active ingredient found in Wegovy. Get all the straight facts in our quick guide.
A new tablet-based medication has beaten oral semaglutide (Rybelsus) for weight loss.
by Simon Edward 30 March 2026
A new tablet-based medication has beaten oral semaglutide (Rybelsus) for weight loss. Let's unpack the results to see what they really mean.
Is there a secret to maximising weight loss on Mounjaro? Follow our step-by-step guide
by Simon Edward 27 March 2026
Is there a secret to maximising weight loss on Mounjaro? Follow our step-by-step guide for straight facts and evidence-based tips.
Are you planning to take your Wegovy or Mounjaro weight loss pens abroad? Here are all the key facts
by Simon Edward 23 March 2026
Are you planning to take your Wegovy or Mounjaro weight loss pens abroad? Here are all the key facts you need to know.
There are many causes of obesity, but can genetics play a part? Learn how
by Simon Edward 20 March 2026
There are many causes of obesity, but can genetics play a part? Learn how our DNA can influence our weight, and what we can do about it.
Learn about the link between obesity and kidney stones, and whether weight loss medication can help
by Simon Edward 16 March 2026
Learn about the link between obesity and kidney stones, and whether weight loss medication can help to reduce risk.
Want to improve your diet? Learn what protein is, how much you need
by Simon Edward 13 March 2026
Want to improve your diet? Learn what protein is, how much you need and how good nutrition supports healthy weight loss.
More posts