Best Weight Loss Pills in the UK: What Actually Works (November 2026)

01 · The verdict

Which weight loss pill works best?

For most people who qualify, a GLP-1 tablet is the most effective pill option, because it reduces appetite in the same way as the weekly injections. Wegovy tablets and Foundayo gave similar average results in their main trials.⁶⁷ Orlistat is an older option that works in the gut rather than on appetite. It helps some people, but the average weight loss is smaller and it only works if you keep fat in your diet low.

• Want the most weight loss from a tablet: a GLP-1 tablet such as Wegovy tablets or Foundayo.
• Prefer a medicine that does not affect appetite: orlistat 120mg or Xenical.
• Want a lower-strength pharmacy option: Alli 60mg.
• Want the most weight loss overall: the weekly injections still give more on average than any tablet. See which weight loss injection is best.

02 · How to order

How to get prescription weight loss tablets

Choose a treatment, complete the free online consultation, and a GPhC-registered prescriber reviews it and decides what is suitable. If it is approved, our pharmacy dispenses it and sends it with free next-day tracked delivery. Current prices are shown on each product page and on our orlistat prices and Alli prices pages.

Wegovy tablets, Foundayo and orlistat 120mg are prescription-only medicines, supplied only after an online consultation reviewed by a GPhC-registered prescriber. They are used alongside a reduced-calorie diet and more physical activity. Individual results vary. This page is information, not a substitute for medical advice.

03 · The pills that are licensed

Which weight loss pills are licensed in the UK?

Only a handful of tablets are licensed medicines for weight management in the UK:

• Wegovy tablets (oral semaglutide, made by Novo Nordisk), approved by the MHRA in June 2026.¹²
• Foundayo (orforglipron, made by Eli Lilly), approved in August 2026.³
• Orlistat 120mg, including the brand Xenical, on prescription.⁴
• Alli (orlistat 60mg), a lower-strength pharmacy medicine.⁵

Mysimba (naltrexone with bupropion) is another licensed tablet, but it is prescribed much less often. Everything else sold as a "weight loss pill", from green tea extract to so-called fat burners, is a food supplement rather than a licensed medicine. Supplements do not have to prove they work in the way medicines do.

04 · GLP-1 tablets explained

GLP-1 weight loss tablets: Wegovy tablets and Foundayo

GLP-1 tablets work like the weekly injections. They copy a gut hormone that tells your brain you are full and slows the rate at which your stomach empties, so you feel satisfied with less food. The difference is that you take a tablet every day instead of an injection every week.

Wegovy tablets

In the OASIS 4 trial, adults taking semaglutide 25mg tablets for 64 weeks lost on average 13.6% of their body weight, compared with 2.2% on placebo.⁶ Treatment starts at 1.5mg once daily and steps up to 4mg, 9mg and then the 25mg maintenance dose, with at least one month at each dose; the dose can stay at an earlier step if needed.¹

Foundayo

In the ATTAIN-1 trial of 3,127 adults without type 2 diabetes, people taking the highest dose of orforglipron for 72 weeks lost on average 12.4% of their body weight, compared with 0.9% on placebo; the two lower doses gave 7.8% and 9.3%.⁷ Treatment starts at 0.8mg once daily, then steps up to 2.5mg and 5.5mg, and then to 9mg, 14.5mg or 17.2mg depending on response and tolerability, with at least 30 days at each dose; 17.2mg once daily is the maximum.³

Our guide to the Wegovy pill vs the injection compares the two forms of semaglutide.

05 · How to take them

How to take weight loss tablets properly

Tablets only work well if you take them the right way, and the rules differ between medicines.

• Wegovy tablets: the tablet must be taken on an empty stomach after fasting for at least 8 hours, swallowed whole with a sip of water (up to half a glass, about 120ml), and you then wait at least 30 minutes before eating, drinking or taking other tablets.¹ Most people take it first thing in the morning. If a dose is missed, skip it and take the next tablet the following day.
• Foundayo: take it once a day as your prescriber directs, following the patient leaflet that comes with it.³
• Orlistat and Alli: take one capsule with each main meal that contains fat, during the meal or up to an hour afterwards. If you miss a meal or eat one with no fat, skip that dose.⁴⁵

06 · Orlistat, Xenical and Alli

Orlistat, Xenical and Alli: how they work

Orlistat blocks some dietary fat absorption and produces smaller average losses than the GLP-1 medicines.⁴ Roughly 30% of the fat in a meal passes through the gut without being absorbed, which reduces the calories you take in. It does not reduce appetite.

The catch is that the unabsorbed fat has to go somewhere. If a meal is high in fat, orlistat can cause oily spotting, wind with an oily discharge, urgent bowel movements and fatty stools.⁴ Keeping each meal low in fat makes these much less likely, which is also why orlistat works best alongside a low-fat, reduced-calorie diet.

• Orlistat 120mg and Xenical are prescription medicines. Xenical is the original brand; generic orlistat contains the same medicine.
• Alli contains orlistat 60mg and is a pharmacy medicine for adults with a BMI of 28 or above.⁵

Because orlistat can reduce absorption of some vitamins, a multivitamin taken at bedtime is often recommended.⁴ See our orlistat prices for Xenical and generic orlistat.

07 · Side effects compared

Weight loss pill side effects compared

The side effects depend on how each medicine works.

• GLP-1 tablets (Wegovy tablets and Foundayo): the most common side effects are digestive, such as nausea, constipation, diarrhoea, vomiting, indigestion and stomach pain, usually in the first weeks and after dose increases.¹³
• Orlistat and Alli: oily spotting, wind with discharge, urgent or more frequent bowel movements, especially after fatty meals.⁴

Foundayo may make oral contraceptive pills less effective: switch to a non-oral method or add a barrier method for 30 days after starting and for 30 days after each dose increase.³ Tell the prescriber about every medicine you take, because some interact with these treatments.

08 · Pills vs injections

Weight loss pills vs injections

The weekly injections still give the most weight loss on average. In the SURMOUNT-1 trial, people taking tirzepatide (Mounjaro) lost on average 20.9% of body weight on 15mg over 72 weeks, and in STEP 1 adults on semaglutide 2.4mg injections (Wegovy) lost 14.9% over 68 weeks.⁸⁹

Tablets suit people who would rather not inject, or who find a daily routine easier than a weekly one. The trade-offs are a daily dose and, for Wegovy tablets, strict rules about food and water. Some people start on an injection and move to a tablet later, or the other way round; the prescriber decides when to switch and which dose to start on. People on the 2.4mg weekly Wegovy injection can move to the 25mg tablet, starting one week after their last injection.¹

09 · Supplements and fat burners

What about supplements, diet pills and fat burners?

Many products sold as weight loss pills in shops and online are food supplements, not medicines. They are not assessed by the MHRA for whether they work, and none has evidence anywhere near the trials behind the licensed tablets on this page.

Some products sold online as "diet pills" are worse than useless. Unlicensed slimming pills have been found to contain hidden prescription drugs or banned substances. If a product promises rapid weight loss without diet changes, is sold without any health questions, or claims to be a "natural Ozempic", treat it with suspicion. Licensed weight loss medicines are only supplied by registered pharmacies.¹⁰

10 · Who can take them

Who can take prescription weight loss tablets?

The GLP-1 tablets are licensed for weight management in adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity.¹³ Orlistat 120mg is prescribed on similar criteria, and Alli is for adults with a BMI of 28 or above.⁴⁵

None of these medicines is suitable in pregnancy or while breastfeeding, and the prescriber will take extra care with some medical conditions and medicines. That is why every order starts with a consultation reviewed by a GPhC-registered prescriber. Our page on who can get weight loss treatment explains the criteria.

11 · NHS options

Can you get weight loss pills on the NHS?

Orlistat has been available on the NHS for many years for people who meet the criteria, usually alongside diet and activity support from their GP practice. The newer GLP-1 tablets are mainly available privately for now. If you think you may qualify for NHS treatment, ask your GP practice.

Privately, you can get Wegovy tablets, Foundayo, orlistat and Alli from a registered online pharmacy after a consultation. Compare the total cost over several months, because tablets are taken every day and the dose usually rises in the first months.