Foundayo (Orforglipron): The Small-Molecule GLP-1 Tablet Explained

Foundayo is the brand name for orforglipron, a once-daily GLP-1 tablet made by Eli Lilly. It works on the same receptor as Wegovy and the GLP-1 part of Mounjaro, reducing appetite and slowing stomach emptying, but it is a small-molecule drug rather than a peptide. That means it can be taken at any time of day, without food or water restrictions. The MHRA authorised Foundayo on 10 August 2026 for weight management in adults and for type 2 diabetes, making the UK the first country in Europe to approve it. In the ATTAIN-1 trial, the highest dose led to an average weight loss of 12.4% over 72 weeks.

What makes orforglipron different

Most GLP-1 medicines, including semaglutide (Wegovy, Ozempic, Rybelsus), liraglutide (Saxenda) and tirzepatide (Mounjaro), are peptides: chains of amino acids modelled on natural hormones. Peptides are broken down in the digestive system, so they are usually injected. The only peptide GLP-1 tablets, oral semaglutide products, need an absorption enhancer and strict fasting rules.

Orforglipron is a non-peptide small molecule. It was designed to bind to and activate the GLP-1 receptor in a similar way to the natural hormone, but its chemical structure is closer to a conventional tablet medicine. This has several practical consequences:

• It is absorbed from the gut without an enhancer, so it does not need to be taken fasting or with a measured amount of water.
• It is processed by the liver, which means some interactions differ from those of peptide GLP-1s.
• It may be simpler to manufacture at scale than peptides, although this does not necessarily translate into lower prices for patients.

Our oral GLP-1 guide explains how orforglipron fits alongside oral semaglutide.

How Foundayo works on weight

Once absorbed, orforglipron activates GLP-1 receptors in the brain and gut. The effects are similar to other GLP-1 medicines:

• Reduced appetite and earlier fullness, through action on appetite centres in the brain.
• Slower stomach emptying, so food stays in the stomach longer.
• Improved blood glucose control, by increasing insulin and lowering glucagon when glucose is high.

Unlike tirzepatide, it does not act on the GIP receptor. Our guide to what GLP-1 medications are explains the hormone system in plain English.

UK licence

The MHRA authorised Foundayo on 10 August 2026. According to the UK SmPC, it is licensed for:

• Weight management, including weight loss and weight maintenance, alongside a reduced-calorie diet and increased physical activity, in adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition.
• Type 2 diabetes, to improve blood glucose control in adults whose diabetes is not adequately controlled, either alone or with other diabetes medicines.

It is a prescription-only medicine.

Doses and how to take it

The dose schedule

According to the UK SmPC:

Not everyone needs to reach the maximum dose. Your prescriber will decide whether and when to increase, based on how well you are responding and how you are tolerating side effects. The SmPC states that you should never take more than one tablet a day to reach a higher dose.

Why the tablet doses differ from the trial doses

If you read about orforglipron trials, you will see doses of 6mg, 12mg and 36mg. Those trials used capsules. The UK-marketed film-coated tablets are absorbed differently, so the milligram numbers are different. The SmPC states that the trial capsule doses of 6mg, 12mg and 36mg correspond to tablet doses of 5.5mg, 9mg and 17.2mg respectively. Capsules and tablets are not interchangeable milligram for milligram.

Taking the tablet

• Take one tablet once a day, at any time of day.
• It can be taken with or without food or water restrictions.
• Try to take it at roughly the same time each day to build a routine.
• If you miss a dose, take it as soon as possible, but do not take more than one tablet in a day.

What the trials show

ATTAIN-1: weight management

ATTAIN-1 (NEJM, 2025) was the main weight-management trial. It enrolled 3,127 adults with obesity, or overweight with at least one weight-related condition, without diabetes, across nine countries. The average starting BMI was 37. Participants took orforglipron (6mg, 12mg or 36mg capsules) or placebo once daily for 72 weeks, alongside lifestyle advice.

Figures from the UK SmPC summary of ATTAIN-1 (efficacy estimand, which estimates the effect in people who continued treatment). Under the treatment-regimen estimand, which includes people who stopped treatment, average weight loss was somewhat lower, at around 7.5%, 8.4% and 11.2%, compared with 2.1% on placebo.

ATTAIN-1 also reported improvements in waist circumference, triglycerides, blood pressure and markers of inflammation such as C-reactive protein.

ATTAIN-MAINTAIN: switching from injections

ATTAIN-MAINTAIN tested whether orforglipron could help people maintain weight loss achieved on injectable semaglutide (Wegovy) or tirzepatide (Zepbound, the US brand of the medicine sold as Mounjaro in the UK). Topline results released by Eli Lilly reported that people who switched to orforglipron maintained most of their weight loss over a year compared with those switched to placebo, with better maintenance after switching from semaglutide than from tirzepatide. At the time of writing, these were company-reported results; check the peer-reviewed publication for full details. Our guide to switching from an injection to a tablet covers what this may mean in practice.

ACHIEVE trials: type 2 diabetes

The ACHIEVE programme tested orforglipron in type 2 diabetes. In ACHIEVE-3 (The Lancet, 2026), orforglipron lowered HbA1c and body weight more than oral semaglutide over 52 weeks in adults with type 2 diabetes taking metformin. Importantly, that trial compared orforglipron with oral semaglutide at diabetes doses (Rybelsus), not with the 25mg Wegovy tablet used for weight management, so it does not show which tablet produces more weight loss in people without diabetes.

How it compares with other medicines

These trials differ in design, population and timing, so they cannot be compared directly. On average, orforglipron's highest dose produced somewhat less weight loss than semaglutide or tirzepatide in their respective trials. For some people, its flexibility may matter as much as the average figure. Our Mounjaro vs oral GLP-1 tablets and tablets vs injections guides compare the options in more detail.

Side effects

Common side effects

According to the UK SmPC, the most common side effects are gastrointestinal:

• Very common (more than 1 in 10 people): nausea, constipation, diarrhoea, vomiting, indigestion and abdominal pain.
• Common (up to 1 in 10 people): dizziness, headache, fast heart rate, low blood pressure, bloating, reflux, wind, gallstones, hair loss, tiredness and raised pancreatic enzymes.

In the weight-management trials, the SmPC reports that most gastrointestinal side effects were mild (around 62%) or moderate (around 34%), with around 4% severe. They are most likely during dose increases. In ATTAIN-1, between about 5% and 10% of people on orforglipron stopped because of side effects, compared with about 3% on placebo.

Managing side effects

• Eat smaller meals and stop when you feel full.
• Avoid very fatty, rich or greasy foods, especially after a dose increase.
• Stay well hydrated.
• If side effects are persistent, talk to your prescriber, who may delay the next dose increase.

Our guides to oral GLP-1 side effects and nausea on GLP-1 medication offer practical tips.

Serious risks

The SmPC lists several warnings, many shared across the GLP-1 class:

• Acute pancreatitis, which is rare but can be serious.
• Gallbladder disease, including gallstones.
• Severe gastrointestinal reactions and acute kidney injury from dehydration.
• Low blood pressure.
• Hypoglycaemia when used with insulin or sulfonylureas.
• Diabetic retinopathy complications in people with diabetes.
• Pulmonary aspiration during general anaesthesia or deep sedation.

Interactions

Because orforglipron is a small molecule processed by the liver, its interactions differ in some ways from those of peptide GLP-1s.

Oral contraceptives

This is one of the most important practical points. The UK SmPC states that orforglipron may reduce the effectiveness of oral hormonal contraceptives. It advises people using oral contraceptives to switch to a non-oral method, or add a barrier method, for 30 days after starting Foundayo and for 30 days after each dose increase.

Non-oral methods include the contraceptive implant, injection, intrauterine device (coil) or intrauterine system. Our guide to GLP-1s and contraception explains how this compares with tirzepatide, which has similar advice, and semaglutide.

Other medicines

The SmPC also describes interactions with:

• Strong CYP3A4 inhibitors or inducers, which can raise or lower orforglipron levels.
• OATP1B inhibitors, which can affect orforglipron levels.
• Simvastatin, where the SmPC advises reducing the dose.
• Insulin and sulfonylureas, where doses may need reducing to avoid hypoglycaemia.

Tell your prescriber and pharmacist about every medicine, herbal remedy and supplement you take, including St John's wort, which can affect liver enzymes. Our GLP-1 medication interactions guide has more detail.

Pregnancy and breastfeeding

According to the SmPC, Foundayo is not recommended in pregnancy, because animal studies showed reproductive toxicity. It should be stopped at least three weeks before a planned pregnancy, a shorter period than for semaglutide because orforglipron leaves the body more quickly. It should not be used while breastfeeding. See our pregnancy and fertility guide.

What we do not yet know

Because orforglipron is newly licensed, it is worth being clear about the gaps in the evidence:

• Long-term outcomes. ATTAIN-1 lasted 72 weeks. Data on weight maintenance and safety over many years are still being collected.
• Cardiovascular outcomes. Unlike semaglutide injections, which have the SELECT trial, orforglipron does not yet have published cardiovascular outcome results in people with obesity.
• Head-to-head comparisons for weight. Orforglipron has not been compared directly with Wegovy tablets 25mg, semaglutide 2.4mg injections or tirzepatide for weight management in people without diabetes.
• Real-world use. Trial participants are carefully selected and supported. How orforglipron performs in everyday UK practice, including how many people stay on it, will become clearer over time.
• The marketed tablet. The main trials used capsules. The SmPC sets out the equivalent tablet doses, but most of the published experience is with the capsule form.

None of these gaps means the medicine is unsafe or ineffective; they are normal for a new medicine. They are, however, reasons for regular review and for reporting any suspected side effects through the MHRA Yellow Card scheme.

Practical tips for the first months

• Pick a consistent time. Although Foundayo can be taken at any time, a fixed daily time makes it easier to remember.
• Sort out contraception first. If you use the pill, arrange a non-oral method or barrier protection before you start, and remember the 30-day precaution after each dose increase.
• Expect side effects after increases. Gastrointestinal effects are most likely in the days after a dose step and often settle.
• Eat with your new appetite. Smaller portions, regular meals and enough protein help with both side effects and muscle preservation. Our guide to protein on GLP-1 medication has practical advice.
• Stand up slowly if you feel light-headed, as low blood pressure is a listed side effect, particularly if you also take blood pressure medicines.
• Keep a simple log of your dose, weight and any side effects to discuss at reviews.

Questions to ask a prescriber

• Is Foundayo suitable for me, or would another tablet or an injection be a better fit?
• How quickly will we increase the dose, and how will we decide when to stop increasing?
• What contraception should I use, and for how long?
• Do any of my current medicines interact with orforglipron?
• How and when will we review whether it is working?
• If I am switching from an injection, how should the changeover be timed?

Who might Foundayo suit?

Foundayo may suit people who:

• prefer a tablet to an injection
• have irregular routines that make fasting before a tablet difficult
• take several morning medicines
• want a medicine that does not need refrigeration
• have type 2 diabetes as well as overweight or obesity, since it is licensed for both

It may be less suitable for people who:

• rely on the contraceptive pill and do not want to use additional or alternative contraception
• take medicines with significant interactions
• want the largest average weight loss seen in trials, which has been with tirzepatide injections
• need medicines with established cardiovascular outcome evidence, such as semaglutide injections under the SELECT trial

These are general points; the decision rests with a prescriber who knows your health and history. Our Foundayo hub and oral GLP-1 hub bring together related information.

UK access

NHS

At the time of writing, NICE was assessing orforglipron for overweight and obesity, with guidance expected in November 2026. Until a NICE recommendation is published, Foundayo is not routinely available on the NHS for weight management. Check the NICE website for the latest position.

Private prescription

Following MHRA authorisation, Foundayo became available through private prescribers. A regulated provider should carry out a full assessment, including your weight, medical history, contraception and other medicines. Our provider comparison sets out how services differ. Costs depend on the dose, the provider and what is included; our prices page explains the factors.

Common questions about the name

"Foundayo" is the brand name; "orforglipron" is the generic (international non-proprietary) name. You may see both in news coverage, trial reports and prescriptions. If you see orforglipron sold online outside a regulated pharmacy, or offered as a "research chemical", do not use it. Our guide to weight loss tablets in the UK explains how to recognise licensed products.

When to speak to a professional

Speak to your GP, pharmacist or prescriber if:

• You are considering Foundayo and want to know whether it is suitable for you.
• You use the contraceptive pill or are planning a pregnancy.
• You take other regular medicines, particularly statins, diabetes medicines or medicines that affect liver enzymes.
• Side effects are affecting your ability to eat or drink normally.
• You feel dizzy or light-headed, particularly when standing up, which may suggest low blood pressure.
• You want to switch from an injection to Foundayo or vice versa.

Seek urgent medical help (NHS 111, or 999 in an emergency) if you have:

• Severe, persistent abdominal pain, which may spread to your back, with or without vomiting (possible pancreatitis).
• Pain in the upper right abdomen, fever, or yellowing of the skin or eyes (possible gallbladder problems).
• Persistent vomiting or diarrhoea with signs of dehydration, such as dizziness or passing very little urine.
• Fainting or a very fast heartbeat.
• Signs of a severe allergic reaction, such as swelling of the face or throat or difficulty breathing.

Whether Foundayo is right for you is a decision for a qualified prescriber who knows your medical history.