Foundayo UK (Orforglipron): What We Know About the New Weight-Loss Pill

Foundayo has now been approved in the UK. The once-daily weight-loss pill contains orforglipron and was authorised by the MHRA on 10 August 2026 for weight management and type 2 diabetes.

It is one of the biggest new developments in medical weight management this year because it offers GLP-1 treatment as a standard tablet. There are no injections and, unlike oral Wegovy, no fasting or water restrictions around the dose.

Foundayo is expected to launch privately in the UK later in August 2026. It is not currently available on the NHS.

This guide explains what Foundayo is, how well orforglipron worked in trials, its side effects, how it compares with injections and what UK patients need to know before considering treatment.

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What is Foundayo?

Foundayo is the brand name for orforglipron. It is a once-daily GLP-1 weight-management tablet made by Eli Lilly, the company behind Mounjaro.

Orforglipron is different from medicines such as semaglutide because it is a small-molecule, non-peptide GLP-1 receptor agonist. In simple terms, it has been designed to work as an ordinary tablet.

Like other GLP-1 medicines, it acts on signals involved in hunger and fullness. This can help people eat less and lose weight when treatment is combined with a reduced-calorie diet and increased physical activity.

Why is Foundayo UK attracting so much attention?

The main reason is convenience.

Foundayo is taken once a day and can be taken:

• with or without food;
• at any suitable time of day; and
• without special restrictions on water.

That is different from oral Wegovy, which has to be taken after fasting, with a limited amount of water, followed by a wait before food, drinks or other tablets.

For people who dislike injections or find strict morning tablet routines difficult, Foundayo could therefore be an important new option.

How much weight did people lose with orforglipron?

The main phase 3 weight-loss study was called ATTAIN-1. It included 3,127 adults with obesity, or overweight plus at least one weight-related health condition, but without type 2 diabetes.

After 72 weeks, average weight loss using the treatment-regimen analysis was:

• 7.4% with the 5.5 mg dose;
• 8.3% with the 9 mg dose;
• 11.1% with the 17.2 mg dose; and
• 2.1% with placebo.

At the highest dose, 71.5% of people lost at least 5% of their starting weight and 54.5% lost at least 10%.

You may also see reports saying Foundayo produced about 12.4% weight loss. That figure comes from an analysis looking at people who remained on treatment. The 11.1% figure is more useful when discussing results across the whole treatment group.

Trial averages do not predict exactly what one person will lose. Results depend on dose, response, side effects, eating pattern, activity and other health factors.

Is UK Foundayo as effective as Mounjaro or Wegovy?

Current trial results suggest Foundayo produces less average weight loss than the strongest injectable options.

Representative results from separate studies include:

• Foundayo 17.2 mg: about 11.1% at 72 weeks;
• oral Wegovy 25 mg: about 13.6% at 64 weeks;
• Wegovy injection 2.4 mg: about 14.9% at 68 weeks;
• Wegovy injection 7.2 mg: about 18.7% at 72 weeks; and
• Mounjaro: about 21.6% at 72 weeks in a direct study against standard-dose injectable semaglutide.

These figures come from different trials, so they should not be treated like a league table. They do, however, show the main trade-off: Foundayo may offer easier dosing in return for lower average weight loss than the most effective injections.

Could Foundayo be used after weight-loss injections?

This is one of the most interesting areas of the evidence.

In the ATTAIN-MAINTAIN trial, people who had previously lost weight with tirzepatide or semaglutide injections were switched to orforglipron or placebo.

Among people who had reached a weight plateau, those switched to orforglipron kept more of their previous weight loss than those switched to placebo over the following year.

This suggests Foundayo could have a future role as an oral maintenance option after successful injectable treatment.

It does not prove that switching to Foundayo works as well as staying on Mounjaro or Wegovy. The study did not include a group that continued the injections.

What are the side effects of Foundayo?

The most common side effects are similar to other GLP-1 treatments and mainly affect the digestive system.

At the highest dose in pooled weight-management trials, reported effects included:

• nausea in about 35% of patients;
• diarrhoea in about 25%;
• vomiting in about 24%;
• constipation in about 24%; and
• indigestion, stomach pain, reflux, tiredness and headache in smaller numbers.

These effects were often more noticeable while the dose was being increased.

Important but less common risks can include pancreatitis, gallbladder problems, dehydration, kidney problems linked to severe vomiting or diarrhoea, serious allergic reactions and low blood sugar when used with some diabetes medicines.

Does Foundayo have drug interactions?

Yes. This is an important difference from many existing injectable GLP-1 medicines.

Orforglipron is a small molecule that is partly processed through the CYP3A4 enzyme system. The current US prescribing information includes restrictions with some strong CYP3A4 inhibitors and inducers, and limits the dose of simvastatin when used with Foundayo.

Oral hormonal contraception may also need extra precautions when Foundayo is started and after dose increases.

The final UK prescribing information should be checked before treatment because UK recommendations may differ from the US label.

When will Foundayo be available in the UK?

The MHRA authorised Foundayo in Britain on 10 August 2026. Lilly has said it expects a private UK launch later in August.

As of 14th August 2026, it is therefore approved but still at the very start of its UK rollout.

A confirmed UK retail price has not yet been published. Lilly has said the private list price is expected to be lower than the highest-dose Mounjaro list price, but the exact cost is still unknown.

Foundayo is not currently available through the NHS. NICE is assessing orforglipron for overweight and obesity, with guidance currently expected on 18 November 2026.

Who might Foundayo suit in the UK?

Foundayo may be particularly interesting for someone who:

• wants medical weight-management treatment but strongly dislikes injections;
• would struggle with the fasting rules required for oral Wegovy;
• already takes daily tablets and prefers that routine;
• has difficulty storing or travelling with injectable medicines; or
• is considering an oral maintenance option after injectable treatment.

It will not be the right choice for everyone. Medication interactions, other health conditions, pregnancy plans, side-effect risk and weight-loss goals all need to be considered.

A new medicine can also have less real-world safety experience than treatments that have been widely used for several years.

Can you buy Foundayo online in the UK?

Foundayo is a prescription-only medicine. Once it is commercially available, a regulated provider should only supply it after a proper clinical assessment and prescription.

Be cautious of any website or social-media seller claiming to supply Foundayo before legitimate UK stock is available, or offering it without an assessment.

PrimeLife’s pharmacy-led weight-management programme assesses each patient individually. Treatment decisions are based on clinical suitability, not simply a request for a particular medicine.

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Frequently asked questions

Is Foundayo the same as Mounjaro?
No. Foundayo contains orforglipron and works on the GLP-1 receptor. Mounjaro contains tirzepatide and acts on both GIP and GLP-1 receptors.

Is Foundayo a peptide?
No. Orforglipron is a small-molecule, non-peptide GLP-1 receptor agonist. This is one reason it can be made as a conventional tablet.

Does Foundayo need to be taken on an empty stomach?
No. Current prescribing information allows it to be taken with or without food and without the special water restrictions used with oral semaglutide.

Is Foundayo available on the NHS?
Not at present. NICE is reviewing orforglipron, with final guidance currently expected in November 2026.

How much will Foundayo cost in the UK?
A confirmed UK retail price had not been published as of 13 August 2026. Lilly has indicated that its private list price will be below the highest-dose Mounjaro list price.

Clinical sources

• NICE: Orforglipron for managing overweight and obesity [ID6516]
• New England Journal of Medicine: ATTAIN-1 orforglipron obesity trial
• Nature Medicine: ATTAIN-MAINTAIN trial
• FDA: Foundayo approval