What is Foundayo? Everything You Need to Know About the New Weight Loss Tablet

Foundayo is the brand name for orforglipron, a prescription medicine used for weight management alongside a reduced-calorie diet and increased physical activity.

Orforglipron belongs to a group of medicines known as GLP-1 receptor agonists.

GLP-1 is a naturally occurring hormone involved in several processes within the body, including appetite regulation. Medicines that act on the GLP-1 receptor can help you feel fuller, reduce hunger and make it easier to eat less.

You may already recognise this type of treatment from medicines such as  ⁠Mounjaro or Wegovy. However, one of the things that makes Foundayo particularly interesting is the way the medicine itself has been developed.

Orforglipron is a small-molecule GLP-1 receptor agonist. This allows it to be taken as a conventional daily tablet rather than an injection.  

We’ll explore the differences between the oral treatments in more detail in our dedicated Foundayo vs Wegovy Pill guide.

No. Foundayo is not an oral version of Mounjaro.

It’s an understandable assumption. Both medicines are made by Eli Lilly, both are used for weight management and both act on the GLP-1 receptor.

But they are different medicines.

Foundayo contains orforglipron and acts on the GLP-1 receptor.

Mounjaro contains tirzepatide and acts on two receptors: GIP and GLP-1.

This difference matters. You shouldn’t think of a Foundayo tablet as being equivalent to a particular dose of Mounjaro, and the results seen with one medicine shouldn’t be assumed to apply to the other.

If you’re already using Mounjaro and are interested in moving to an oral treatment, switching may be possible for some patients, but this should always be planned with your prescriber rather than trying to convert the doses yourself.

There are now several different types of prescription medicine available to support weight management.

Some, including Mounjaro and Wegovy Injection, are administered as weekly injections. Foundayo is instead taken as one tablet every day.

That’s likely to make it particularly appealing to people who:

• would prefer not to inject themselves
• dislike needles
• travel frequently
• work shifts
• have an irregular routine
• simply find a tablet more convenient

It’s also different from other oral weight loss treatments such as orlistat. Orlistat works primarily by reducing the amount of dietary fat absorbed by the gut, whereas Foundayo works through the GLP-1 pathway and appetite regulation. You can read more about the different types of  weight loss tablets available in the UK in our dedicated guide.

There are also differences between Foundayo and the recently approved Wegovy Pill. Both are oral GLP-1 treatments, but the medicines themselves are very different. We’ll cover this properly in our Foundayo vs Wegovy Pill guide rather than trying to squeeze the comparison into this article.

If you’re unsure whether a tablet or injection would better suit your lifestyle, our guide to choosing between a  ⁠weight loss pill or injection can help you understand some of the practical considerations.

Foundayo works by activating GLP-1 receptors in the body.

GLP-1 is released naturally after eating and forms part of the body’s signalling system between the gut and brain.

Orforglipron acts on this pathway in several ways that can support weight loss.

It reduces appetite

GLP-1 signalling affects areas of the brain involved in appetite and food intake.

For many people, this means feeling less hungry and finding it easier to eat smaller amounts of food.

It helps you feel fuller

GLP-1 medicines can increase feelings of fullness and satiety after eating.

This can make reducing your overall calorie intake feel more manageable than relying on willpower alone.

It slows gastric emptying

Foundayo can delay gastric emptying, meaning food may move from the stomach into the intestine more slowly.

This contributes to the feeling of fullness but is also one of the reasons GLP-1 medicines can cause gastrointestinal side effects and potentially affect the absorption of some other oral medicines.  

Foundayo isn’t intended to replace healthy eating or physical activity. It is used alongside a reduced-calorie diet and increased physical activity to support longer-term weight management.  

The headline patients understandably want to know is: how much weight could I lose?

The largest Phase 3 studies give us a good indication.

ATTAIN-1

ATTAIN-1 studied adults living with obesity, or overweight with at least one weight-related health condition, without type 2 diabetes.

At the highest dose, people taking orforglipron lost an average of approximately 11.2% of their starting body weight in the main analysis.

A separate analysis estimating the effect if participants remained on treatment as intended found an average reduction of approximately 12.4%.

By comparison, participants receiving placebo lost approximately 2% of their starting weight.

The trial also found improvements in measures including waist circumference, systolic blood pressure, triglycerides and non-HDL cholesterol.  

For somebody starting at 100 kg, an 11.2% reduction would equate to approximately 11 kg of weight loss on average.

That doesn’t mean everyone taking Foundayo will lose 11–12% of their weight. Some people will lose more and some less.

ATTAIN-2

ATTAIN-2 looked specifically at adults living with overweight or obesity and type 2 diabetes.

At the highest dose, participants achieved average weight loss of approximately 10.5% in the efficacy analysis.

That’s important because losing weight can sometimes be more difficult for people living with type 2 diabetes.

Taken together, the ATTAIN programme demonstrates that once-daily oral orforglipron can produce clinically meaningful weight loss alongside diet and physical activity.

However, these results shouldn’t be directly compared with headline percentages from completely separate Mounjaro, Wegovy or other weight-loss trials. Different trials involve different patients, methods and treatment periods.

Like other GLP-1 medicines, Foundayo can cause side effects.

The most common are gastrointestinal and include symptoms such as:

• nausea
• diarrhoea
• vomiting
• constipation
• abdominal discomfort
• indigestion.

In ATTAIN-1, gastrointestinal side effects were the most commonly reported adverse events and were mostly mild to moderate.  

This is broadly consistent with what we see across the GLP-1 class. Gastrointestinal symptoms are also common with treatments such as Wegovy and Mounjaro, particularly when starting treatment or increasing the dose.

Foundayo is therefore started at a low dose and gradually increased. This gives your body time to adjust and can help improve tolerability.

There are also less common but potentially serious risks associated with treatment, which will be explained by your prescriber and in the Patient Information Leaflet supplied with your medicine.

Always read the leaflet before starting treatment and contact the clinical team if you develop side effects that are severe, persistent or concerning.

One of Foundayo’s biggest practical advantages is how straightforward it is to take.

It is taken as one tablet once a day.

Foundayo can be taken:

• at any time of day;
• with or without food; and
• without having to plan your dose around a fasting window.

The tablet should be swallowed whole and should not be split, crushed or chewed.  

Taking your tablet at around the same time each day can be a useful way to build it into your routine.

Treatment starts at a lower dose before gradually increasing, depending on how you’re responding to treatment and whether you’re experiencing side effects.

There isn’t a set point at which everyone suddenly feels Foundayo “kick in”.

Some people may notice changes in appetite earlier than others, but clinical effects and weight loss develop over time.

It’s important not to judge your response based on the first few days or weeks of treatment.

Foundayo is deliberately started at a lower dose and gradually increased to help your body adjust. Your response may therefore change as treatment progresses.

Weight management is also about much more than the medicine itself. Foundayo should be used alongside a balanced, reduced-calorie diet and regular physical activity.

Give your treatment time to work, follow your prescribed dosing plan and focus on progress over weeks and months rather than day-to-day changes.

Not necessarily - and that’s not really the most useful way to look at it.

Different treatments offer different advantages.

Injectable medicines such as Mounjaro have produced greater average weight loss in separate clinical trials, while Foundayo provides a different proposition: clinically meaningful weight loss from a once-daily tablet without injections or strict fasting requirements.

For one patient, maximum potential weight loss may be the priority. For another, avoiding injections or having a treatment that fits more easily around travel, work or family life may matter more.

The best treatment is the one that is clinically appropriate, effective, tolerable and sustainable for you.

You can explore the wider range of ⁠weight management treatments available from Cloud Pharmacy or discuss the options with one of our prescribing clinicians.

This is another particularly interesting area for orforglipron.

Foundayo has been studied in people who had already achieved substantial weight loss using injectable GLP-1 treatment and then transitioned to oral orforglipron.

Rather than trying to cover that evidence here, we’ve explored it properly in our dedicated Foundayo and Weight Maintenance guide, including what the ATTAIN-MAINTAIN trial found and how Cloud Pharmacy approaches longer-term weight management.

Foundayo is a once-daily oral GLP-1 weight management medicine containing orforglipron.

It isn’t oral Mounjaro. Although both medicines are developed by Eli Lilly, Foundayo acts on the GLP-1 receptor, while Mounjaro acts on both GIP and GLP-1 receptors.

The clinical evidence shows that Foundayo can produce meaningful weight loss, with average reductions of around 11–12% at the highest dose in ATTAIN-1, alongside diet and physical activity. Its main practical advantage is simple daily administration without injections or the strict fasting routine associated with some oral GLP-1 treatments.  

That doesn’t make it automatically better than Mounjaro, Wegovy or another weight management treatment. It makes it another option — and for some people, the convenience of a daily tablet may make it an option that fits particularly well into everyday life.

1. Wharton S, et al. ATTAIN-1: Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment. New England Journal of Medicine. ⁠View the ATTAIN-1 publication
2. US Food and Drug Administration. FOUNDAYO (orforglipron) tablets – Prescribing Information.  ⁠View FDA prescribing information
3. Eli Lilly and Company. Foundayo (orforglipron) – US patient and product information.  ⁠View Lilly Foundayo information