What Is the Best Weight Loss Pill? UK Guide (October 2026)

01 · The honest answer

So which weight loss pill is best?

The honest answer is that it depends on you. Two weight-loss pills are now licensed in the UK: Wegovy tablets (oral semaglutide, approved by the MHRA in June 2026) and Foundayo (orforglipron, approved in August 2026). Both are prescription-only.²⁰²¹

Each is licensed for adults with a BMI of 30 or above, or 27 to under 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity.²⁰²¹ Neither is an over-the-counter product, and anything sold over the counter as a 'GLP-1 pill' is not a licensed medicine.

Mounjaro (tirzepatide) is the other major licensed weight-management option, but it is a once-weekly injection and there is no tablet version.¹ If you specifically want a pill, our guide on a weight loss pill instead of an injection goes deeper. If you are open to a weekly injection, you can see the Mounjaro pen prices and consultation.

02 · Side by side

Wegovy tablets, Foundayo and Mounjaro compared

The table compares practical differences only. No trial has compared Mounjaro directly with either tablet, so trial averages from separate studies should not be set against each other.²⁰²¹

Our Wegovy pill page and Foundayo page carry the current tablet prices. For a wider look at price-led comparisons, see our GLP-1 pill pricing guide.

03 · Costs

What Mounjaro costs if you choose the injection

A Mounjaro pen is one four-week supply. Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99). Switching to us at a higher dose? A first order at 15mg is £289.99. Every later order is £25 off the standard price (code DOSE25).

If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices. A first year (13 pens) costs £2,711.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,599.88 if you step up through every dose to 15mg. A new customer's first order is £40 less and every later order £25 less. All six doses are in stock, and the price shown is the price paid.

04 · Getting started

How ordering works

Ordering takes three steps. First, complete the free online consultation, a short health questionnaire with no charge and no obligation. Second, a GPhC-registered prescriber reviews it. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

Third, our registered pharmacy dispenses and dispatches the same day when you order by 3pm. Delivery is free, next-day, tracked and in temperature-controlled packaging. Mounjaro comes through official LillyDirect supply, direct from Eli Lilly's UK distribution. Ongoing monthly reviews are included, and repeat orders re-check suitability with no auto-shipping.

If you want to explore all the routes, our weight loss treatments hub lists everything we supply.

05 · Wegovy tablets explained

Wegovy tablets: what they are and how they work

Wegovy tablets contain semaglutide, the same active ingredient as the Wegovy injection, taken as one tablet once a day.²⁰ They were approved by the MHRA in June 2026 and are made by Novo Nordisk. They are licensed for weight management in adults with a BMI of 30 or above, or 27 to under 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity.²⁰

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.²⁰ That flexibility matters, because the right dose is the one your prescriber judges suitable for you rather than the highest one available.

The morning routine

The routine is strict, and it is the biggest practical difference from other options. The tablet must be taken on an empty stomach after fasting for at least 8 hours. Swallow it whole with a sip of water, up to half a glass (about 120ml). Then wait at least 30 minutes before eating, drinking or taking other tablets.²⁰

If you miss a dose, skip it and take the next tablet the following day.²⁰ People who like a fixed morning routine may find this easy. People who eat early, take regular morning medicines or have irregular shifts may find it harder to keep up.

What the OASIS 4 trial showed

In OASIS 4, adults taking semaglutide 25mg tablets for 64 weeks lost on average 13.6% of their body weight, compared with 2.2% on placebo. In the same trial, 76.3% lost at least 5% of their body weight (30.5% on placebo) and 59.8% lost at least 10% (14.1% on placebo).²² These are trial averages, individual results vary, and the medicine works alongside diet and activity, not instead of them.

To put 13.6% in context: for someone starting at 100 kg, 13.6% is about 13.6 kg. That is simple arithmetic on the trial average, not a prediction of your own result.

Switching from the injection

People on the 2.4mg weekly Wegovy injection can move to the 25mg tablet, starting one week after their last injection.²⁰ If that is you, our Wegovy pill page has current prices and the consultation route.

06 · Foundayo explained

Foundayo (orforglipron): the once-daily tablet from Lilly

Foundayo contains orforglipron, a once-daily GLP-1 tablet made by Eli Lilly, the maker of Mounjaro. It was approved in the UK in August 2026.²¹ Unlike Wegovy tablets, it can be taken at any time of day, with or without food and without water restrictions. The tablet is swallowed whole.²¹

It is licensed for adults with a BMI of 30 or above, or 27 to under 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity.²¹ For many people the lack of food and timing rules is the deciding factor, especially with shift work or a busy morning.

Dosing steps

Treatment starts at 0.8mg once daily, then steps up to 2.5mg and 5.5mg. After that it moves 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.²¹ If you miss a dose, take it as soon as possible, but never more than one tablet a day.²¹

What the ATTAIN-1 trial showed

In ATTAIN-1, a 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%.²³ The trial used capsules, and the UK 17.2mg tablet corresponds to the highest trial dose, so tablet and capsule doses are not comparable milligram for milligram.²³

Side effects were mainly digestive: nausea, constipation, diarrhoea, vomiting, indigestion and stomach pain. In the trial, 10.3% of people on the highest dose stopped because of side effects, compared with 2.7% on placebo.²³

Contraception

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.²¹ Our Foundayo guide covers cost and UK availability, and the Foundayo product page shows current prices.

07 · Mounjaro: the injection

Mounjaro: the weekly injection

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹ There is no tablet form of Mounjaro; tirzepatide is injection-only in the UK.

How it works

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin. Most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹ This dual action distinguishes it from single-action GLP-1 medicines such as semaglutide.

SURMOUNT-1 results

In SURMOUNT-1, a trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks. People using lifestyle changes alone lost 3.1%.² At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight. Half of those on 10mg and 57% on 15mg lost at least 20%.²

For someone starting at 100 kg, 20.9% is about 21 kg. These are trial averages, so they do not predict your own result.

The one direct comparison we have

SURMOUNT-5 is the first large head-to-head trial. Adults on tirzepatide lost on average 20.2% of body weight over 72 weeks versus 13.7% on semaglutide 2.4mg (Wegovy injection). Average loss was 22.8 kg versus 15.0 kg.¹⁵ That trial compared two injections. It does not tell us how either tablet compares with Mounjaro, and no trial has made that comparison.

Both treatments are effective and licensed. Which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.

08 · Which Mounjaro level suits

Which Mounjaro dose is right for weight loss?

The right dose is the one your prescriber finds effective and tolerable for you; higher is not automatically better. Mounjaro comes in six strengths from 2.5mg to 15mg, and treatment is stepped up under prescriber supervision.¹ Our dedicated guides, which mg is best for weight loss and what dose suits you, go deeper.

What the trial shows by dose

In SURMOUNT-1, average losses over 72 weeks were 15% on 5mg, 19.5% on 10mg and 20.9% on 15mg.² The proportion losing at least 5% was 85% on 5mg, 89% on 10mg and 91% on 15mg. Those figures show benefit across doses rather than a single required strength.

The 2.5mg pen is the starting dose, so it is not a long-term target.

What each stage costs

At standard prices, a pen costs £169.99 at 2.5mg, £218.99 at 5mg, £279.99 at 7.5mg, £290.99 at 10mg, £319.99 at 12.5mg and £329.99 at 15mg, each per month (one 4-week pen). Weekly, that works out at £42.50, £54.75, £70.00, £72.75, £80.00 and £82.50.

New customers save £40 on their first order at any dose with code FIRST40. After that, an automatic £25 reorder discount applies to every future order (code DOSE25). If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices.

A first year (13 pens) costs £2,711.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,599.88 if you step up through every dose to 15mg, before discounts. For 7.5mg, 10mg or 12.5mg, use the monthly prices above rather than a year figure. Our weight loss medication discount guide explains how the live discounts work.

Prescriber review at every step

Ongoing monthly reviews, dose-titration and follow-up assessments are part of our aftercare. Repeat orders re-check suitability, with no auto-shipping, so your dose reflects how you are doing rather than a fixed schedule.

09 · Eligibility, NHS and private

Who can use weight loss medicines: NHS and private routes

Eligibility starts with BMI. Mounjaro is 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. Examples include high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes.¹ It must be used alongside a reduced-calorie diet and increased physical activity. A prescriber assesses your BMI, medical history and current medicines before deciding whether it is suitable.

Wegovy tablets and Foundayo share the same licensed BMI thresholds, and both are prescription-only.²⁰²¹

The NHS picture

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition. The NHS primary-care rollout began in June 2025 with the highest-need groups first, initially BMI 40+ with four or more qualifying conditions.⁴⁶ Full rollout is expected to take years.

That is why many people who meet the licensed criteria choose regulated private treatment rather than waiting. NHS access to Wegovy runs through specialist weight-management services; ask your GP. Your GP is also the right first call if you are unsure whether you qualify on the NHS.

Choosing a regulated private route

A regulated route means a GPhC-registered pharmacy, a prescriber review and genuine supply. We are GPhC-registered (9012878), and you can check the GPhC register entry. Mounjaro reaches us through official LillyDirect supply, direct from Eli Lilly's UK distribution, with genuine KwikPens.¹²

Be cautious of any seller offering to supply without a consultation or prescription. Counterfeit weight-loss products have been the subject of MHRA alerts, and the Yellow Card scheme is where suspected problems are reported.⁷

Cost of running a pill versus an injection

Tablet prices change, so the product pages show current figures. Across the UK pharmacies we track, 2.5mg starting pens run from £143.96 to £179.99 per month (checked 10 October 2026).

10 · Other options and non-medicines

Orlistat, Saxenda, Wegovy injection and supplements

Orlistat

Orlistat is a tablet that blocks some dietary fat absorption. It produces smaller average losses than the GLP-1 medicines. Your prescriber can advise on suitability. Our page on appetite suppressants and weight loss pills looks at the wider pill category.

Wegovy and Saxenda injections

The Wegovy injection (semaglutide) comes as 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg pens once weekly. Treatment steps up after at least 4 weeks, reaching the 2.4mg maintenance dose from week 17.¹⁸ In STEP 1, adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.⁹ In that trial, 86.4% lost at least 5% of body weight, 69.1% at least 10% and 50.5% at least 15%.

Saxenda (liraglutide) is another licensed injectable, supplied at 6mg per millilitre. It is a daily injection, unlike once-weekly Mounjaro and Wegovy. Our review of available weight loss drugs compares these options.

Ozempic is not a weight-loss licence

Ozempic is semaglutide licensed for type 2 diabetes. It is not a UK weight-loss medicine, and prescribing it privately for weight loss is off-label. The licensed weight-management options are Mounjaro and Wegovy 2.4mg, so 'Mounjaro versus Ozempic' for weight loss is really Mounjaro versus Wegovy. A regulated UK pharmacy will not supply Ozempic for weight loss.¹⁸

'Poor man's Ozempic' and natural GLP-1 supplements

Products sold as 'natural GLP-1' or 'nature's Ozempic', such as berberine, are not medicines. They are not regulated for weight loss and have no comparable trial evidence. They are available cheaply without assessment, which is part of the problem: there is no clinical oversight, and dosing is not standardised. A low-cost supplement is not a cheaper version of a GLP-1 medicine.

Unlicensed 'research' products and stacking

Mounjaro must not be combined with other GLP-1 medicines, unlicensed 'research' peptides (such as retatrutide, which has no UK licence), or compounded copies. These combinations have no safety data and no regulated supply chain. If something promises faster results outside a licensed pathway, that is the warning sign. Never run two GLP-1 medicines together.⁷

11 · Safety and side effects

Safety, side effects and pregnancy

Every GLP-1 medicine has side effects, and the most common ones are digestive. For Wegovy tablets these include nausea, vomiting, diarrhoea, constipation, indigestion and stomach pain, along with headache and tiredness. Gallstones and hair loss are listed as common.²² For Foundayo, the most common side effects are also digestive: nausea, constipation, diarrhoea, vomiting, indigestion and stomach pain.²³

Stopping because of side effects

In ATTAIN-1, 10.3% of people on the highest orforglipron dose stopped because of side effects, compared with 2.7% on placebo.²³ In STEP 1, gastrointestinal side effects were reported by 74.2% of people on semaglutide 2.4mg injection, compared with 47.9% on placebo. 7.0% stopped treatment because of side effects, compared with 3.1% on placebo.⁹ These come from different trials with different people and should not be compared directly.

If you notice a new symptom, tell your prescriber. You can also report suspected side effects through the MHRA Yellow Card scheme.⁷

Contraception

Pills and injections interact differently with oral contraception. Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed. The SmPC advises switching to a non-oral method, or adding a barrier method such as condoms, for 4 weeks after starting and for 4 weeks after each dose increase. This applies to the pill only; implants, coils and injections are unaffected.¹

Foundayo may also make oral contraceptive pills less effective, with a 30-day window after starting and after each dose increase.²¹

Pregnancy and breastfeeding

Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive. If you become pregnant during treatment, stop the medicine and tell your prescriber promptly.¹ Current prescribing information indicates minimal transfer of tirzepatide into breast milk; discuss breastfeeding with your prescriber.

Stopping Mounjaro

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4–5 weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹ Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average. Stopping should always be planned with your prescriber, with diet and activity habits ready to carry the load.

Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice. Our support team is available Monday to Friday, 9am to 5pm on 0333 207 0413.

12 · Choosing between them

How to choose between a pill and an injection

Start with your routine, not the averages. Mounjaro is a once-weekly injection, Wegovy tablets and Foundayo are once-daily tablets, and the practical differences matter as much as the trial numbers.²⁰²¹ A prescriber checks which option is suitable for your health, your other medicines and your routine.

If a daily tablet suits you

Wegovy tablets suit people who can fast for at least 8 hours, take the tablet with a sip of water and then wait at least 30 minutes before food, drink or other tablets. Foundayo suits people who want no food or water rules and can take a tablet at any time of day.²⁰²¹ Both involve a daily habit, and a missed dose means either skipping it (Wegovy tablets) or taking it as soon as possible, never more than one tablet a day (Foundayo).

If you prefer one injection a week

Mounjaro needs one injection a week, with needles, a sharps bin and injection guidance included with every order. People who dislike daily routines, or who find an empty-stomach rule awkward, often prefer that.¹

If you already take another GLP-1

There is no licensed direct conversion between semaglutide and tirzepatide. Switching is done under prescriber supervision: typically the previous medicine is stopped, a washout interval is observed, and Mounjaro is started at a dose your prescriber judges appropriate, often 2.5mg. Never run two GLP-1 medicines together.¹ Switching to us at a higher dose is possible, and the new-customer discount applies to a first order at any dose.

Questions to take to your consultation

Useful questions include: which of these is licensed for me, how do my current medicines interact, what happens if I miss a dose, and how will my dose be reviewed? You can start our free consultation with no obligation. The consultation is free, and the price shown is the price paid. You can also use Klarna or pay-monthly options, with no subscription lock-in, and the free GLPTrackr app to track your journey.

13 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹