The Wegovy pill has the highest reported average weight loss of UK licensed prescription weight loss pills. Comparison comes down to what each pill did in clinical trials. The Wegovy pill (semaglutide), achieved on average 13.6% body weight loss over 64 weeks.
Which prescription weight loss pill gives the most weight loss?
The Wegovy tablet is currently the 'strongest' prescription pill for weight loss available in the UK. It contains semaglutide, and achieves the most weight loss for patients taking it .
People who took 25mg a day, lost 13.6% of their body weight after 64 weeks. This compared against 2.2% for people taking a placebo pill (an inactive tablet).
Foundayo (orforglipron) is the also a daily GLP-1 tablet. This was also released in 2026.
Foundayo averaged 11.2% body weight loss after 72 weeks of use, compared to 2.1% on placebo.1 These results come from clinical trials.
The trials, looked at different groups of people over different lengths of time. However Wegovy and Foundayo were the weight loss pills which achieved the highest average body weight loss.
If you are still deciding whether a tablet is worth starting, do weight loss pills work covers that question.
Do milligrams tell me how strong a pill is?
The active drug is more important than how many milligrams. Milligrams measure how much drug is in the tablet, not how much weight you will lose.
Each drug works differently, so more mg does not mean a stronger effect between different drugs.
For example 120mg of orlistat has not been shown to be more effective, or 'stronger', than 25mg of the Wegovy pill.
How the licensed weight loss pills compare
There are four main prescription pills are licensed for weight management in the UK. Two of these are new daily oral GLP-1 tablets, released in 2026, one is a twice-daily tablet called Mysimba, and one is orlistat, which you take with your meals. They all work slightly differently.
Semaglutide 25mg tablets (the Wegovy pill)
Wegovy tablets are licensed for weight management in adults. When using Wegovy, you should aim to also achieve a lower-calorie diet and increase your activity level for best results.6 The highest dosage prescribed is 25mg a day.6
Take one tablet on an empty stomach, after 8 hours without food.6 You should then wait at least 30 minutes before you eat, drink or take anything else.6 The dose steps up from 4mg, 9mg and 25mg, with at least a month at each strength.6
Higher strength doses can also means more side effects. About half of people on the 25mg semaglutide tablet felt sick during its trial, comapared to about 20% of those taking a placebo.6 If a dose is making you ill, tell your prescriber rather than pushing on to the next one.
Orforglipron tablets (Foundayo)
Foundayo could be viewed as the second "strongest" of the prescription weight loss pills. This is because it achieved the second highest average in body weight loss in trials. It is also the easiest of these tablets to fit into a day. You can take one tablet at any time, with or without food. It is licensed for weight management, alongside a lower-calorie diet and increased activity.7
The maximum dose of Foundayo is 17.2mg a day. The starting dose is 0.8mg and patients move up to 2.5mg after at least 30 days.7
You should not take Foundayo in pregnancy.
Naltrexone and bupropion tablets (Mysimba)
Mysimba (naltrexone and bupropion), averaged 5.4% weight loss after 56 weeks in trials. This compared against 1.3% for patients taking placebo.22
The Mysimba dose builds up gradually to two tablets twice a day.2 Mysimba should be stopped after 16 weeks if you have not lost at least 5% of your starting weight.2
If you continue taking, your GP should review treatment every year.2
Orlistat 120mg, and alli 60mg
Orlistat is the only prescription weight loss pills you take with your main meals.
You should take one 120mg capsule with each main meal. Either just before it, during, or up to one hour after.
Higher Orlistat doses have not been shown to work any better.3
Orlistat's UK licence covers adults with a BMI of 30 or more, or who are overweight with a weight-related risk factor.
Alli, is the pharmacy version of Orlistat. It is the same medicine at a lower strength (60mg). It is 60mg three times a day, and no more than three capsules in 24 hours.8
| Medicine | How you take it | Highest licensed dose | Average weight loss in its own trial |
|---|---|---|---|
| Wegovy tablets (semaglutide) | One tablet a day on an empty stomach, then a 30-minute wait | 25mg a day | 13.6% after 64 weeks, against 2.2% on placebo |
| Foundayo (orforglipron) | One tablet a day, any time, with or without food | 17.2mg a day | 11.2% after 72 weeks, against 2.1% on placebo |
| Mysimba (naltrexone and bupropion) | Tablets twice a day, built up gradually | Two tablets twice a day | 5.4% after 56 weeks, against 1.3% on placebo |
| Xenical (orlistat), prescription strength | One capsule with each main meal | 120mg three times a day | 3.2kg more than placebo over a year |
| alli (orlistat), pharmacy strength | One capsule with each main meal | 60mg three times a day | No separate figure here: the same medicine at a lower strength |
How much weight do people lose on each pill?
On average, people lose between 5% to 14% of their starting weight on the tablets. This is not as strong a result as the injections.
However these are trial averages. Your results can of course vary. Some people will lose much more, while others may lose almost nothing.
Smaller results can still be worth having.
Losing 5 to 10% of your weight improves your health and lowers your risk of serious conditions.
GLP-1 pills also have two other effects on your body. They
- reduce your appetite
- keep you feeling full for longer.4
Is the Wegovy tablet stronger than Foundayo?
In terms of the average body weight loss in trials, yes.
Wegovy (semaglutide) tablet has the higher reported weight loss figure. There is more detail in the Wegovy pill compared with Foundayo.
Are the pills as strong as the weekly injections?
No. No tablet has matched the same weight loss figure that weekly injections have in a trial. Over 72 weeks, Mounjaro, tirzepatide reduced body weight by 21.6%, comapred to 15.4% for the Wegovy injection. Both are injcted under the skin rather being taken orally however.9
Does a higher dose always mean more weight loss?
No - each pill works differently - so higher dosage does not mean more weight loss. The drug is the bigger factor.
- Orlistat: 120mg with each main meal is the top dose.
- Wegovy tablets: 25mg a day, and never two tablets to make a bigger dose.
- Foundayo: 17.2mg a day, and no extra tablets.
- Mysimba: two tablets twice a day at most.
Who can and cannot take these pills
None of the four can be used in pregnancy.
Alli must not be taken with warfarin or another blood-thinning tablet.8 Tell us on your assessment if you take one.
Tell us everything you take on your assessment, including pharmacy medicines and supplements. If you are choosing between the two GLP-1 tablets, who can take an oral GLP-1 goes through some of the checks. Our GPs will take a comprehensive medical history from you, so they can determine if you are eligible for treatment.
Side effects, and when to stop and get help
Most side effects are digestive and improve over time.
However, while on a GLP-1 tablet, you should get urgent advice for
- a swollen throat or tongue, a raised itchy rash or difficulty breathing.
- Severe stomach or back pain that does not go away. This can mean an inflamed pancreas.
- Sudden loss of vision, usually in one eye at a time, also needs urgent attention.11
Call NHS 111 if you think you are having a serious side effect.11
How to get a weight loss pill in the UK
For the strongest weight loss pills, you will need a prescription either from your own GP or online..
Prescription weight loss pills are usually only prescribed at a BMI of 30 or more. If you have a BMI of 28 or more, and have a weight-related condition such as type 2 diabetes or high blood pressure, you may also be eligible. This also goes for certain ethnic groups who may be at higher risk of heart disease.
Frequently asked questions
What is the strongest dose of orlistat you can take?
120mg with each main meal, three times a day.
Is there a tablet as strong as Mounjaro injections?
No tablet has matched it in a trial. Mounjaro is a weekly injection, and no trial has compared a tablet against it.
Is there a Mounjaro Pill?
No. This is often sometimes confused as with Foundayo pills, which is from Eli Lilly, the manufacturer of Mounjaro injections.
Can you buy strong weight loss pills over the counter?
No. The pharmacy strength of orlistat is lower than the prescription strength. The strongest weight loss pills in the UK are prescription only.
Do I have to fast before taking a weight loss tablet?
Only with the Wegovy (semaglutide) tablet. Foundayo can be taken anytime, while orlistat should be taken with your meals.
How long can you take a weight loss pill for?
There isn't a set end date for taking weight loss pills. It's usually based on your weight loss. Orlistat is usually stopped after 12 weeks without 5% weight loss. Mysimba is stopped after 16 weeks without 5% weight loss. GLP1s are often after you have achieved a specific BMI or if weight loss has stalled.
What happens if I stop taking a weight loss pill?
Talk to your GP before stopping treatment. They can give advice on how to manage your weight afterwards.
Can I take a weight loss pill in pregnancy or while breastfeeding?
No. None of these four pills is used in pregnancy. Orlistat, Wegovy and Mysimba should not be taken while breastfeeding. Tell your prescriber if you are pregnant, trying for a baby or breastfeeding.
Is a weight loss pill enough on its own?
No. Every one of them is licensed alongside a lower-calorie diet and more activity, and that is how each was tested.
Key takeaways
- Wegovy achieved the highest average weight loss in trials
- The second most effective or strongest weight loss pill is Foundayo
- Higher milligrams doesn't mean a stronger medicine.
Sources
References
This page lists 13 sources. Numbered markers in the text link to 9 of them, and a pharmacist approved each of those citations. Each cited source links back to where it is cited.
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Oral Semaglutide 25 mg Versus Orforglipron 36 mg in Obesity: A Population-Adjusted Indirect Treatment Comparison, Diabetes, Obesity and Metabolism, 2026 [Accessed 5 October 2026]. Relevant sections: Introduction; Methods, study outcomes; Abstract, results; Funding statement; Discussion, limitations. https://pmc.ncbi.nlm.nih.gov/articles/PMC13341387/
Cited in the text:↑a
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Mysimba 8 mg/90 mg prolonged-release tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 5 October 2026]. Relevant sections: 5.1 Clinical efficacy and safety, narrative and Table 3, NB-301 intent-to-treat analysis; last observation carried forward; 5.1 Clinical efficacy and safety, study designs; 4.1 Therapeutic indications; 4.2 Posology, individual population restrictions also apply; 4.1 stopping rule; 4.2 annual reassessment; 4.2 Posology; 5.1 Table 3, intent-to-treat analysis footnote +; 4.3 Contraindications; 4.3 Contraindications; selected examples, consult full list; 4.6 Pregnancy; 4.6 Breast-feeding. https://www.medicines.org.uk/emc/product/2684/smpc
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Xenical 120 mg hard capsules: Summary of Product Characteristics, electronic medicines compendium, 2023 [Accessed 5 October 2026]. Relevant sections: Section 5.1 Pharmacodynamic properties, pooled 2-year studies; Section 4.2 Posology and method of administration; Section 4.1 Therapeutic indications; Section 4.4 Special warnings and precautions for use; Section 4.8 Undesirable effects, post-marketing table, hepatobiliary disorders. https://www.medicines.org.uk/emc/product/2592/smpc
Cited in the text:↑a
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Overweight and obesity in adults, NHS, 2026 [Accessed 5 October 2026]. Relevant sections: Weight loss medicines; Risks of living with overweight and obesity. https://www.nhs.uk/conditions/overweight-and-obesity/
Cited in the text:↑a
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Orlistat: a medicine to treat obesity, NHS, 2026 [Accessed 5 October 2026]. Relevant sections: What orlistat is for; Pregnancy and orlistat; Who can and cannot take orlistat; Orlistat and contraception; Serious side effects; If you take too much orlistat; What orlistat is for, eligibility list. https://www.nhs.uk/medicines/orlistat/
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Wegovy 25 mg tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 5 October 2026]. Relevant sections: Section 4.1 Therapeutic indications; Section 4.2 Posology, Adults; Section 4.2 Method of administration; Section 4.8 Gastrointestinal adverse reactions; Section 4.6 Pregnancy; Section 4.6 Breast-feeding; Section 4.4 Acute pancreatitis; Section 4.4 Non-arteritic anterior ischaemic optic neuropathy; Section 4.2 Switching from semaglutide injection to semaglutide tablets. https://www.medicines.org.uk/emc/product/102347/smpc
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Foundayo 14.5 mg film-coated tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 5 October 2026]. Relevant sections: Section 4.2 Method of administration; Section 4.1 Therapeutic indications, weight management; Section 4.2 Posology; Section 5.1 Clinical efficacy and safety, Table 2; Section 4.6 Pregnancy; Section 4.5 Oral contraceptives; Section 4.4 Acute pancreatitis; Section 4.8 Post-marketing and relevant product information, eye disorders. https://www.medicines.org.uk/emc/product/102531/smpc
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alli 60 mg hard capsules: Summary of Product Characteristics, electronic medicines compendium, 2023 [Accessed 5 October 2026]. Relevant sections: Section 4.2 Posology and method of administration; Section 4.3 Contraindications. https://www.medicines.org.uk/emc/product/6533/smpc
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Mounjaro KwikPen 15mg solution for injection: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 5 October 2026]. Relevant sections: Section 5.1 Clinical efficacy and safety, SURMOUNT-5; Section 4.2 Method of administration. https://www.medicines.org.uk/emc/product/15486/smpc
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Comparative Efficacy of Tirzepatide Versus Semaglutide for Weight Loss in Adults With Overweight or Obesity: A Systematic Review and Meta-Analysis of Head-to-Head Studies, Clinical Obesity, 2026 [Accessed 5 October 2026]. Relevant section: Abstract, results. https://pmc.ncbi.nlm.nih.gov/articles/PMC13527552/
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Semaglutide: a medicine to manage type 2 diabetes or treat obesity, NHS, 2026 [Accessed 5 October 2026]. Relevant sections: Serious side effects; Urgent advice: Call NHS 111 if; If you have too much semaglutide; What semaglutide is for. https://www.nhs.uk/medicines/semaglutide/
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UK first in Europe to authorise orforglipron for weight management and type 2 diabetes, Medicines and Healthcare products Regulatory Agency, 2026 [Accessed 5 October 2026]. Relevant sections: Press release, side effects paragraph; Press release, opening paragraph; Press release, availability paragraph; Press release, notes on supply. https://www.gov.uk/government/news/uk-first-in-europe-to-authorise-orforglipron-for-weight-management-and-type-2-diabetes
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Wegovy 7.2 mg solution for injection in pre-filled pen: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 5 October 2026]. Relevant section: Section 5.1 STEP 4: Sustained Weight Management. https://www.medicines.org.uk/emc/product/102093/smpc
Reference links open the cited source pages. If you spot something out of date, tell our content team.
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