Comparing Oral Weight Management Options: Foundayo, Wegovy Tablets and Orlistat

Injections aren’t the only route into medical weight management any more. 

The UK now has three tablet-based options – Foundayo, Wegovy Tablets, and Orlistat. These work in genuinely different ways, come with different daily routines, and suit different people.

This guide compares all three side by side: how they work, how they’re taken, their side effects, and what the clinical evidence says, so you can have a more informed conversation with a prescriber about which, if any, might be right for you.

This article is for general information only and is not a substitute for a one-to-one consultation with a qualified prescriber. All three medicines discussed are only suitable for some people, and eligibility must be assessed individually.

At a Glance

How Each One Works

Foundayo (orforglipron)

Foundayo is a GLP-1 receptor agonist. It mimics a naturally occurring gut hormone that reduces appetite, increases feelings of fullness, and slows gastric emptying. 

What sets it apart from other oral GLP-1 medicines is that it’s a small molecule rather than a peptide, which is why it doesn’t come with the strict fasting rules described below.

Wegovy Tablets (oral semaglutide)

Wegovy Tablets contain the same active ingredient (semaglutide) as the well-known Wegovy injection, but in tablet form. 

It works the same way (appetite reduction, increased satiety, slower gastric emptying) but because it’s a peptide-based molecule, it needs specific conditions to be absorbed properly, which is where the fasting requirement comes from.

Orlistat

Orlistat works completely differently to the other two. It isn’t a GLP-1 medicine at all. It’s a lipase inhibitor, meaning it blocks the enzyme that breaks down roughly a third of the fat in a meal, so that fat passes through the digestive system largely unabsorbed rather than being stored. 

It doesn’t affect appetite directly; it changes how much fat your body takes in from food.

Fasting and Timing Rules – The Biggest Practical Difference

This is where the three options diverge the most, and it’s often the deciding factor for patients choosing between them.

• Foundayo – no fasting required. It’s generally taken at a consistent time each day, with or without food (your prescriber or patient information leaflet will confirm specifics for your dose).
• Wegovy Tablets – strict rules: taken on an empty stomach after fasting for at least 8 hours, swallowed whole with no more than 120ml of plain water, followed by a 30-minute wait before any food, drink, or other oral medicine. Splitting, crushing or chewing the tablet, or not waiting the full 30 minutes, can reduce how much of the medicine is absorbed.
• Orlistat – the opposite problem: it must be taken before, during, or within an hour of a meal that contains fat. If a meal has no fat in it, you skip that dose entirely, since there’s nothing for it to act on.

In practice, this means Foundayo fits most easily around a busy or unpredictable routine, Wegovy Tablets require real day-to-day discipline around timing, and Orlistat requires you to think about the fat content of every meal.

Who Can Take Each Medicine

Foundayo and Wegovy Tablets are licensed for adults with:

• A BMI of 30 or above, or
• A BMI of 27–29.9, with at least one weight-related health condition (such as high blood pressure, high cholesterol, or prediabetes)

Orlistat is used in similar overweight/obesity populations but has its own additional considerations. 

A prescriber will typically want to see a 5% or greater weight loss within the first three months of starting orlistat. If that target isn’t met, it’s usually stopped, since it’s unlikely to be effective for you. 

Orlistat is also unsuitable for anyone with a chronic malabsorption condition, cholestasis, or chronic kidney disease, and shouldn’t be used in pregnancy, while breastfeeding, or under the age of 18.

Foundayo has its own specific exclusions: a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2, severe liver impairment, or pregnancy/breastfeeding.

None of these criteria are a substitute for a full consultation. A prescriber needs your complete medical history and current medications before recommending any of the three.

Side Effects Compared

Foundayo – very common (more than 1 in 10 people): nausea, vomiting, constipation, diarrhoea, indigestion, abdominal pain. Common: dizziness, headache, increased heart rate, low blood pressure, bloating, acid reflux, hair thinning, fatigue.

Wegovy Tablets – most commonly nausea, diarrhoea, constipation and vomiting, particularly in the early stages of treatment or after a dose increase, easing as the body adjusts.

Orlistat – because of how it works, side effects are digestive and fat-related: oily or fatty stools, needing to go to the toilet urgently or more often, flatulence (sometimes with oily spotting), stomach pain, and diarrhoea. These tend to improve on a lower-fat diet, since they’re directly linked to how much unabsorbed fat is passing through the gut. Rare but serious effects include allergic reactions, acute pancreatitis, and rectal bleeding, which need urgent medical attention.

Foundayo and Wegovy Tablets share a broadly similar side-effect profile because they work the same way. Orlistat’s side effects are a different category altogether and are, to a large extent, within your control through diet.

How Effective Is Each One? Comparing the Evidence

It’s tempting to line up percentages and pick the “winner”, but these figures come from different trials, with different designs, durations and participant groups, 

They aren’t directly comparable in a strict sense. With that caveat:

• Foundayo – in the ATTAIN-1 trial (72 weeks, 3,100+ participants), adults without type 2 diabetes on the highest dose (17.2mg) lost an average of around 11–12% of body weight, compared with roughly 2% on placebo.
• Wegovy Tablets – in the OASIS 4 trial (64 weeks, 307 participants), adults without type 2 diabetes on the 25mg dose lost an average of 16.6% of body weight (intention-to-treat analysis) compared with 2.7% on placebo; in a real-world adherence analysis this was 13.6% versus 2.2%. Around a third of participants achieved 20% or more weight loss, versus under 3% on placebo.
• Orlistat – results are more variable and depend heavily on how closely a low-fat diet is followed alongside it. Some people lose 10% or more of their body weight within six months; others see considerably less, which is why effectiveness is reviewed early (typically at three months).

All three are intended to be used alongside a reduced-calorie diet and increased physical activity, not as a stand-alone solution, and individual results vary considerably from these trial averages.

Which Might Suit You? Practical Considerations

A few practical factors, beyond the headline numbers, are worth thinking about:

• Routine and lifestyle – if a strict fasting window feels unworkable with your daily schedule, Foundayo’s flexibility may suit you better than Wegovy Tablets.
• Relationship with food – Orlistat’s side effects are closely tied to dietary fat, so it may suit someone already committed to a structured lower-fat diet, but can be uncomfortable for anyone who eats a higher-fat diet or eats out frequently.
• Needle-free by design – all three are tablets, so if avoiding injections is your main reason for looking at oral options, all three qualify; the differences are in mechanism and daily routine, not delivery method.
• Access route – Foundayo and Wegovy Tablets are prescription-only following a consultation. Orlistat is also available prescription-only at 120mg (Xenical) or in a lower-strength pharmacy version (such as Alli) without a prescription, though a pharmacist consultation is still required.
• Ongoing monitoring – orlistat can reduce absorption of some fat-soluble vitamins, so a multivitamin (taken at least two hours apart from your dose) is generally recommended. It can also interact with medicines including warfarin, thyroid medication, and the combined contraceptive pill if severe diarrhoea occurs.

Safety First: This Is Not a DIY Decision

None of this replaces an individual clinical assessment. The right choice depends on your health history, current medications, lifestyle, and what a prescriber judges to be safe and appropriate for you. 

Indeed, it may be decided that you aren’t suitable for any oral option and an injectable treatment might be a better fit. 

This article is designed to help you ask better questions in that conversation, not to replace it.

Frequently Asked Questions

Can I switch between Foundayo, Wegovy Tablets and Orlistat? Potentially, but only under medical supervision. Switching between weight management medicines needs a full reassessment by your prescriber, not a decision made independently.

Which oral weight loss tablet is most effective? Trial data suggests Wegovy Tablets produced the largest average weight loss in its own trial, followed by Foundayo, with Orlistat’s results being more variable and diet-dependent. However, these come from separate trials that weren’t run head-to-head, so this isn’t a like-for-like comparison, and individual results vary significantly.

Do all oral weight loss tablets need to be taken on an empty stomach? No. This is specific to Wegovy Tablets. Foundayo has no fasting requirement, and Orlistat is taken with meals rather than instead of them.

Can I buy any of these without a prescription? A lower-strength version of orlistat is available over the counter from a pharmacy (such as Alli) following a pharmacist consultation. Foundayo and Wegovy Tablets are prescription-only and require a full online or in-person consultation with a prescriber.

What are the most common side effects across all three? Foundayo and Wegovy Tablets share similar gastrointestinal side effects (nausea, diarrhoea, constipation, vomiting), most common early in treatment. Orlistat’s side effects are related to fat malabsorption (oily stools, urgency, flatulence) and are strongly influenced by dietary fat intake.

Are these tablets a substitute for injections like Mounjaro? Not automatically. Tablets and injections can produce different results and suit different people. Whether an oral or injectable option is more appropriate is something to discuss directly with your prescriber based on your individual circumstances.

Complete your consultation with onlinemeds today.

References

1. GOV.UK / MHRA — UK first in Europe to authorise orforglipron for weight management and type 2 diabetes
2. Eli Lilly — What Is Foundayo (orforglipron)
3. BioSpace — Novo Nordisk’s oral semaglutide 25mg (Wegovy in a pill) delivered 16.6% weight loss in people with obesity in a newly published study (OASIS 4 trial)
4. NHS — Orlistat: a medicine to treat obesity
5. Patient.info — Orlistat (Weight Loss Medicine): Uses and Side Effects
6. MHRA Yellow Card Scheme — Report a side effect