Comparing Weight Loss Pills in the UK

Approximately 26% of adults in England are obese and almost 38% are overweight, expanding the trend to find appropriate weight loss medications.

Weight loss pills have been a popular option for people looking to shed pounds quickly and effectively. They are designed to aid weight loss by several mechanisms including suppressing appetite, reducing fat absorption, or boosting your metabolic rate.

Weight loss tablets are nothing new. They have been around since the mid-20th Century and have evolved significantly since. In the UK, several pills are available, both prescription-only and over-the-counter options. Here we’ll explore what weight loss pills are available now, how they work, and how you can obtain them.

There are two forms of weight loss pills available, non GLP-1 pills and GLP-1 pills.

GLP-1 weight loss pills

The only approved GLP-1 weight loss pill in the UK is the Wegovy pill. The Wegovy pill contains oral semaglutide, which works in the same way as the Wegovy injection to lower your appetite by making you feel fuller for longer.

Non GLP-1 weight loss pills

Non GLP-1 weight loss pills typically work in 3 ways to encourage weight loss:

1) Appetite suppression

Some pills, like Mysimba, act on the parts of the brain that control food intake and energy balance to suppress your appetite. They also reduce the effect of the part of the brain that associates eating food with reward.

2) Fat absorption reduction

Medications containing orlistat as their active ingredient can prevent the absorption of up to one-third of the dietary fat in a meal, passing it out of the body naturally as stool waste.

3) Enhancing metabolism

Some weight loss capsules claim they increase the body’s metabolic rate – how quickly it burns calories. These are also sometimes known as ‘fat burners’ and work by increasing metabolism, so your body will burn more calories, contributing to weight loss.

• Orlistat

Orlistat, Xenical, and alli contain the same active ingredient, orlistat. They work by stopping the body from absorbing some of the fat in food to aid weight loss.

• Naltrexone and bupropion

Mysimba contains 2 active ingredients to promote weight loss, naltrexone hydrochloride and bupropion hydrochloride. It is a prolonged-release medication, slowly releasing its active ingredients which can minimise the side effects and help with a gradual increase in dose.

Both ingredients work on the area of the brain that controls food intake and energy expenditure.

Several weight loss pills are available in the UK, some are available over-the-counter while others require a prescription from a doctor.

Prescription-only weight loss pills

Wegovy pill

Wegovy pill is an oral semaglutide GLP-1 available in doses 1.5mg, 4mg, 9mg, and 25mg as a maximum maintenance dose. It works to lower your appetite by making you feel fuller for longer, so it works just like the Wegovy injection, it is just taken differently. You take the Wegovy pill on an empty stomach after fasting for at least 8 hours, it should be taken before food with up to 120ml of water. Clinical trials have found that patients have lost 16.6% on average of their starting weight on the Wegovy pill.

Orlistat

Orlistat capsules, available in 120mg capsules, are the generic form of Xenical. Orlistat works best alongside low-fat meals that are spread across 3 sittings. These pills can be taken up to 3 times a day and many people notice the effects within 2 weeks of starting treatment.

You’ll take it for 12 weeks to begin with and your doctor will need to check you’ve lost at least 5% of your starting weight. If you have, orlistat is usually taken for around 6 months to a year but can be taken for longer if it’s still working well for you at this point.

In studies, 37% of people taking orlistat for 12 weeks lose at least 5% of their weight. Another study found that if taken after following a diet plan for 4 weeks before treatment, around 60% of people lose 5% of their weight by week 12. So you’ll get the best effect from the medication if you’re already following a healthy diet and exercise plan.

Orlistat is just as effective as its branded version Xenical but is available at a lower cost, starting at £49.99.

Xenical

A branded version of orlistat that’s available in 120mg capsules. Xenical capsules can be taken up to 3 times a day, before, during, or after a meal containing fat. Like orlistat, you can see results in as little as 2 weeks but your doctor will make sure you’ve lost at least 5% of your starting weight by week 12 before continuing treatment.

It can be taken for as long as it remains effective and suitable for you, usually for around 6 months to a year.

Xenical studies found after 12 weeks, on average, 37% of people lose at least 5% of their weight. Another study showed that up to 60% of people can lose 5% of their weight by week 12 but this was after following a diet plan for 4 weeks before starting the medication. This means you’ll get the best results when following a healthy diet and exercise plan before starting treatment.

Xenical prices start from £57.99.

Mysimba

Mysimba contains naltrexone and bupropion and acts on the part of the brain that regulates your appetite. It signals to your brain that you feel full, curbing food cravings and hunger.

They are available in prolonged-release tablets, and you’ll usually start by taking 1 tablet per day before gradually increasing your dose to 2 tablets, twice a day (morning and evening). After 16 weeks, your doctor will make sure you’ve lost 5% or more of your weight. If you have, you can continue taking Mysimba for as long as you need it under your doctor’s supervision.

Studies show that after just over a year of treatment (56 weeks) people lose on average 8.1% of their starting weight. You’ll see the best results when following a healthy calorie-controlled diet and regular exercise regime.

Mysimba prices start from £115.00.

Over-the-counter weight loss pills

alli

alli is an over-the-counter weight loss medication containing the active ingredient, orlistat. You don’t need a prescription to get it, but you’ll still need to answer a few questions as it’s not suitable for everyone. alli capsules contain 60mg of orlistat, half of the prescribed dose, and, on average, 46.7% of people who take them lose at least 5% of their starting body weight in 6 months. It’s taken just like orlistat or Xenical, up to 3 times a day with meals that contain some fat.

You should start to notice the effects of alli within a few days and weight loss within 12 weeks. If you haven’t lost weight after 12 weeks, you should speak to your doctor or pharmacist. It’s advised that alli should not be taken for longer than 3 months if it is ineffective for you. You’ll need to speak to your doctor after this period about whether you should continue with alli (usually under the doctor’s supervision). Alternatively, they might suggest a different weight loss medication.

alli prices start from £39.50.

The table below shows the similarities and differences between the most popular weight loss pills available in the UK:

Scroll to compare weight loss tablets

All medications can cause side effects, including weight loss pills. Here is a comparison between the side effects across the most common weight loss pills.

If you experience side effects while taking weight loss pills, there are several things you can do to help manage them:

• drink plenty of water or clear fluids to stay hydrated
• eat small meals regularly
• reduce your consumption of fat and sugar, especially with orlistat-based medication as this will increase the chance of very common side effects
• sipping or drinking ginger or peppermint teas can soothe nausea
• get plenty of fresh air
• take over-the-counter painkillers for pain such as headaches
• stay active

If you experience any of the following serious side effects, call 999 or get someone to take you to A&E immediately:

• swollen face
• breathing difficulties
• sweating
• rash
• rapid heartbeat
• collapse

If you experience any side effects that are difficult to manage, contact your doctor.

Prescription-only weight loss tablets may be suitable if you are obese or overweight and:

• are over 18 years old
• have a BMI of 30 or above or
• have a BMI between 27 and 30 and have a weight-related condition, such as high blood pressure, type 2 diabetes, or high cholesterol (blood fat levels)

alli is suitable for adults over 18 with a BMI of 28 or above. You can find out your BMI using our BMI calculator.

Who shouldn’t take weight loss pills?

Weight loss pills are not suitable for everyone.

Do not take weight loss pills if you:

• are allergic to any of their ingredients
• are pregnant or breastfeeding
• have cholestasis
• have problems absorbing food
• are taking blood thinners
• are taking ciclosporin
• are not obese or overweight

You should discuss your health and lifestyle, including any current medical conditions and medications before taking any weight loss pills.

Weight loss pills and pregnancy

Weight loss pills should not be taken by women who are pregnant or are planning to get pregnant.

Weight loss pills and breastfeeding

Weight loss pills are not intended to be taken while breastfeeding because the active ingredients may pass into your breast milk. Speak to your doctor about alternative weight loss treatments if you are currently breastfeeding.

Weight loss tablets and pills are available both with a prescription and over-the-counter depending on which type you require.

Over-the-counter medications, like alli, are available in most pharmacies and do not require a prescription. You can also buy them online.

Prescription-only weight loss medications can be obtained with a prescription. They may be available on the NHS or via a private prescription from reputable online sources.

When buying online, check that the company you are buying from is registered with the Care Quality Commission.

You can request weight loss tablets from Superdrug Online Doctor by:

• completing a short online health and lifestyle questionnaire for one of our doctors to review
• if approved, you can choose to have your medication posted to your address or collected from your local Superdrug Pharmacy in as little as 2 to 3 hours after a doctor’s approval

Are weight loss tablets available on the NHS?

Yes, it is possible to get some weight loss tablets on the NHS.

What weight loss tablets are available on the NHS?

Wegovy pill is not available on the NHS.

Orlistat, also available under the brand name Xenical, is available on the NHS for people who meet the treatment criteria.

Mysimba is not available on the NHS and can only be obtained through a private prescription in the UK. alli is available in pharmacies so you can’t get it on the NHS.

Are weight loss tablets available for free on the NHS?

In England, NHS prescriptions are subject to a prescription charge that you will need to pay unless you are exempt. The current NHS prescription charge is £9.90 per item.

Weight loss pills are not the only available treatment for obesity. Below we discuss the other weight loss treatment options available in the UK.

Prescription medications

Weight loss injections

As well as pills, weight loss injections are available to help you lose weight.

Mounjaro

Mounjaro is a branded, once-weekly self-injectable weight loss pen. It contains the active ingredient tirzepatide which works by mimicking the effects of 2 hormones in your body, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP).

Mounjaro reduces appetite, promotes a more regulated energy balance, and slows digestion. The average weight loss with Mounjaro is 22.5% at the highest dose over 72 weeks.

Wegovy

Wegovy is also a branded, once-weekly, self-injectable weight loss pen, containing the active ingredient semaglutide. It also mimics the GLP-1 hormone to control your appetite and make you feel fuller for longer after eating.

Research shows that Wegovy users can lose an average of 21% of their starting body weight when they take the 7.2mg maintenance dose per week, for 72 weeks.

Surgery

Weight loss surgery, also called bariatric surgery, is sometimes an option for severely obese people. It is usually only available on the NHS and if you meet specific criteria, such as:

• having a BMI of 40 or above or between 35 and 39.9 with a serious health condition that could improve if you lose weight
• having tried all non-surgical treatments but you haven’t achieved or maintained adequate weight loss
• you are fit enough to have surgery under general anaesthetic
• you have been or will receive intensive management as part of your treatment
• you commit to the need for long-term follow-up
• you are of Asian, Chinese, Middle Eastern, Black African or African-Caribbean origin and have a BMI above 37.5 or between 32.5 and 37.4 and have a medical condition that could improve with weight loss

There are different types of weight loss surgery:

• Gastric bypass – where your stomach is divided in 2 with a stomach staple creating a small pouch for food to pass through
• Biliopancreatic diversion or duodenal bypass – similar to a gastric bypass but the stomach pouch is formed further along the small intestine
• Gastric band – an empty silicone band is placed around the top of the stomach
• Sleeve gastrectomy – removes around 80% of the stomach to make it smaller and sleeve-shaped
• Gastric balloon – a balloon is deposited in your stomach and filled with salt water to reduce your stomach size
• Endoscopic sleeve gastroplasty – 1 or more folds are made in the stomach and sewn together to reduce the size of the stomach by 80%

Choosing the best weight loss pill for you will depend on several factors, such as:

• your target weight loss
• the active ingredient in the pill
• your BMI
• any underlying health condition you may have or medications you’re taking
• the cost

“If you are thinking about using a prescription weight loss pill, you’ll need to have a BMI of at least 27 and a weight-related health condition, or a BMI over 30. You’ll also need to make some lifestyle changes, including a healthy diet and exercise plan, to gain their full effects. When you request treatment through our service, we’ll offer an alternative if your preferred treatment is not clinically suitable. We’re also here to support you during your weight loss journey.” – Dr Brenda Ikeji, Medical Editor.

What is the strongest prescription weight loss pill?

Orlistat and Xenical are prescription-strength versions of orlistat, containing 120mg in each capsule. They can be taken up to 3 times a day which is equivalent to 360mg of orlistat per day.

Mysimba contains 8mg of naltrexone and 90mg of bupropion in each tablet. They are also prescription-only but work in a different way to orlistat so the dose cannot be compared.

What are the best weight loss pills for women?

There is no “best” weight loss pill option for women. Deciding which pill will be most effective for you depends on several factors.

For example, if you take the contraceptive pill, orlistat has a very common side effect of loose stools. If you get severe diarrhoea, the pill won’t be as effective so you will need an additional form of contraception until it subsides. There’s still a chance of having diarrhoea on Mysimba but it's much less common.

Both types of weight loss pills cannot be taken if you are pregnant or trying for a baby.

How old do you need to be to buy weight loss pills?

You need to be at least 18 years old to buy over-the-counter weight loss medications and to obtain a prescription for prescription-only medications.

What are the best weight loss supplements?

There is little evidence to suggest that weight loss supplements work and they may cause serious side effects. If you want to lose weight and are unsure about which treatment is best for you, speak to your doctor for advice.