Foundayo vs Rybelsus: which tablet is right for you?

Jump to: What are Foundayo and Rybelsus licensed for in the UK? | Blood sugar and side effects | How much weight did people lose? | What do we know about heart health? | How both drugs are taken | Other medicines and contraception | Starting or switching treatment | Take home message | Frequently asked questions | References

At the highest doses studied, Foundayo (orforglipron) produced greater average reductions in blood sugar and weight than Rybelsus (semaglutide) in adults living with type 2 diabetes.³

The ACHIEVE-3 trial reported an estimated average weight loss of 9.2% with Foundayo and 5.3% with Rybelsus after 52 weeks, assuming people continued treatment.³

Foundayo also lowered HbA1c, a blood test reflecting average blood sugar over recent months, by about 21 mmol/mol, compared with 16 mmol/mol with Rybelsus.³

However, more people stopped Foundayo because of side effects: about 10 in every 100, compared with 5 in every 100 taking Rybelsus.³

Both are tablets taken once a day. Foundayo can be taken with food, while Rybelsus needs to be taken on an empty stomach, 30 minutes you eat or drink anything, or take other oral medications.^1,2

Foundayo contains the drug orforglipron, a small molecule that mimics the actions of the GLP-1 hormone by interacting with GLP-1 receptors in the body to reduce hunger and improve insulin function to lower blood sugar levels.

Rybelsus contains the drug semaglutide, which is a synthetic version of the GLP-1 hormone, so it acts more like a direct copy of the GLP-1 hormone, lowering hunger and blood sugar levels in the same way that orforglipron does.

Rybelsus shouldn’t be confused with the Wegovy pill, which also contains semaglutide. They’re the same drug, but licenced for different treatments and at different doses.

Rybelsus has a maximum dose of 9 mg, and is only available for patients liiving with type 2 diabets in the UK.

Where as the Wegovy pill has a maximum dose of 25 mg, and is available for patients living with obesity, as defined by BMI.

Foundayo is licenced for people living with type 2 diabetes and obesity, for eligible patients.

As already mentioned, Rybelsus is only licensed for type 2 diabetes, so it isn’t an approved treatment for weight loss in the UK.^1,2

What are Foundayo and Rybelsus licensed for in the UK?

Both tablets are licensed in the UK for adults living with type 2 diabetes whose blood sugar isn’t sufficiently controlled.

Foundayo is also licensed for weight management; Rybelsus isn’t licensed for weight loss in the UK.^1,2

Adults with a BMI of 30 and above, or 27-29.9 with at least one obesity-related health condition like high blood pressure, will likely be eligible for Foundayo.

Still, Foundayo isn’t available on the NHS yet and is only available through private providers, such as Second Nature.

Private providers will often have their own prescribing criteria alongside the drug’s licence approved by the MHRA, so meeting the eligibility criteria listed above doesn’t automatically guarantee you’ll be eligible for Foundayo.^1,6

UK prescribing information.^1,2

Both tablets mimic GLP-1, a hormone our body releases after eating. They help our pancreas release insulin, the hormone that lowers blood sugar, and communicate with the brain’s appetite centres to reduce hunger.^1,2

As described earlier, while the drugs have the same effect, they differ in structure.

Oforglipron, the drug in Foundayo, is a small molecule that interacts with GLP-1 receptors to mimic the actions of the GLP-1 hormone, but it isn’t a mimic of the hormone itself.

Whereas semaglutide, the drug in Rybelsus, is a peptide and synthetic copy of the GLP-1 hormone and acts like a direct copy of the hormone in the body.

The outcomes are the same: both drugs lower hunger and improve blood sugar, but they achieve those outcomes in slightly different ways.

Blood sugar and side effects

Foundayo lowered HbA1c by about 5 mmol/mol more than Rybelsus over 52 weeks at the highest doses in ACHIEVE-3.³

The trial included 1,698 adults living with type 2 diabetes whose blood sugar wasn’t sufficiently controlled by metformin, a diabetes medicine.

Participants were randomly assigned to one of two tablet doses and continued taking metformin.³

Average HbA1c fell by about 21 mmol/mol with Foundayo and 16 mmol/mol with Rybelsus. These changes match the paper’s reported 1.91 and 1.47 percentage points.³

The calculation included everyone assigned to each tablet, including people who stopped taking it. This suggests that at their highest available doses, Foundayo leads to slightly greater HbA1c reductions than Rybelsus.³

Which drug caused more side effects?

Stomach and bowel symptoms affected 58% of people taking the highest Foundayo dose and 45% taking the highest Rybelsus dose. That’s about 13 more people in every 100 taking Foundayo.³

Most symptoms were mild or moderate. However, about 10 in every 100 people stopped Foundayo because of side effects, compared with 5 in every 100 taking Rybelsus. This suggests that while Foundayo may lead to greater blood sugar improvements, patients are also more likely to stop taking the medication due to side effects.³

Participants and clinicians knew which tablet each person was taking. Their expectations may therefore have influenced how they reported and recorded symptoms.

For example, someone who expects to experience nausea may be more likely to notice it and attribute it to the drug.³

This means the difference in reported side effects could partly reflect expectations about the treatments. We don’t know whether this affected the results, or by how much.

HbA1c was measured through blood tests, so the blood-sugar comparison was less vulnerable to this source of bias, as participants’ expectations are unlikely to influence it.³

Lilly, Foundayo’s manufacturer, funded the trial and has a financial interest in its results.³

Manufacturer funding can influence how studies are designed, analysed, and presented, so we need to assess those methods when interpreting the findings. This doesn’t mean the results are unreliable, but we should use a bit more caution.

For example, it could be argued that Lilly chose Rybelsus as a comparison drug rather than the Wegovy pill because they were more confident the results would favour Foundayo.

When do side effects need medical help?

Seek immediate medical attention for severe, persistent abdominal pain, which can indicate pancreatitis, inflammation of the pancreas. Stop the medicine if pancreatitis is suspected.^1,2

Call NHS 111 now if you keep vomiting and can’t keep fluids down. Vomiting can cause dehydration, which can worsen kidney function.^1,2

Seek urgent medical advice for sudden loss of vision, including partial loss, while taking Rybelsus.²

Our Foundayo side-effects guide explains how to manage common symptoms and when to seek help.

How much weight did people lose?

At the highest doses in ACHIEVE-3, estimated average weight loss was 9.2% with Foundayo and 5.3% with Rybelsus after 52 weeks, suggesting that Foundayo leads to roughly 4% more weight loss, on average, than Rybelsus.³

These figures assume people continued their assigned treatment without needing extra diabetes medicine. They don’t describe the average result when stopping treatment is also taken into account.³

For someone starting at 100 kg, 9.2% would be 9.2 kg, and 5.3% would be 5.3 kg. Individual weight loss may be higher or lower than the trial average.

Everyone in this comparison was living with type 2 diabetes. Our Foundayo guide covers the separate trials in people without diabetes.

ACHIEVE-3 didn’t investigate the effect of the Wegovy pill on weight loss, another oral semaglutide medication, so these results don’t show how Foundayo compares with it.

Our Wegovy pill vs Rybelsus guide explains how the two semaglutide tablets differ.

What do we know about heart health?

In the SOUL trial, fewer people taking Rybelsus had a heart attack, a stroke, or died from heart and blood-vessel disease than those taking placebo, an inactive tablet.⁴

The trial included 9,650 adults aged 50 or above who were living with type 2 diabetes and had heart or kidney disease. Everyone continued their usual care.⁴

Over roughly four years, 12.0% of people taking Rybelsus had a heart attack or stroke, or died from heart and blood-vessel disease, compared with 13.8% taking placebo. That’s about 18 fewer people in every 1,000.⁴

Because both groups continued their usual care, Rybelsus provided additional protection alongside existing treatment.

The researchers established this protective effect by counting heart attacks, strokes, and deaths from heart and blood-vessel disease, rather than assuming that lower blood sugar would prevent them.⁴

These results suggest that alongside improving blood sugar for people living with type 2 diabetes, these effects also translate into a reduced risk of experiencing a major cardiovascular event.

Foundayo has also been studied in people living with type 2 diabetes who were at high risk of cardiovascular disease.

ACHIEVE-4 compared Foundayo with insulin glargine, a long-acting insulin, in 2,749 adults.⁵

Although these medications work differently, both are used to treat type 2 diabetes. The researchers used insulin as an established treatment to see whether Foundayo caused a large increase in cardiovascular risk.⁵

They recorded heart attacks, strokes, deaths from heart and blood-vessel disease, and hospital admissions for unstable angina, chest pain caused by reduced blood flow to the heart.⁵

Over about two years, 4.2% of people taking Foundayo experienced at least one of these cardiovascular events, compared with 5.0% taking insulin. The difference wasn’t significant enough to show that Foundayo prevented more events than those on insulin.⁵

These results are reassuring about using Foundayo to treat type 2 diabetes in people already at high risk of heart disease.

However, we still don’t know whether it also helps prevent heart attacks or strokes as this trial simply wasn’t long enough for us to see an effect.⁵

Heart and blood-vessel disease develops over many years and is influenced by blood pressure, smoking, blood sugar, air pollution, psychological health, other health conditions, and many other factors.

While we know that high blood sugar and insulin levels impact our risk of heart disease, and that Foundayo improves both of these risk factors, we still don’t know whether these effects lower cardiovascular events without long-term trials confirming this.

Longer follow-up would help us determine the long-term effect of taking Foundayo on cardiovascular health.

Rybelsus has been shown to reduce the combined risk of heart attack, stroke, or cardiovascular death in the people studied in SOUL.

For Foundayo, the evidence supports cardiovascular safety compared with insulin, while its potential to prevent these complications over the long term remains uncertain.^4,5

How both drugs are taken

Foundayo can be taken with breakfast or at any time of day, with or without food.

Rybelsus needs to be taken on an empty stomach, with a minimum 30-minute wait before having any food, drink, or other medications.^1,2

Rybelsus contains an ingredient that helps semaglutide pass through the stomach lining. Food and other tablets can reduce how much reaches the bloodstream, so taking it with breakfast can reduce its effect on lowering blood sugar levels.²

The UK instructions for Rybelsus are to:

1. Take it after a recommended fasting period of at least 8 hours (after sleeping overnight, for example)
2. Swallow the tablet whole with no more than 120 mL of plain water
3. Wait at least 30 minutes before eating, drinking, or taking other medicines by mouth. This includes tea and coffee.²

How long does it take to reach the highest dose?

Reaching the highest Foundayo dose takes at least 150 days (about 5 months), compared with 2 months for Rybelsus.

It can take longer to increase to the highest dose if side effects are impacting quality of life^1,2

Plus, at Second Nature we recommend taking the lowest effective dose for as long as it’s effective.

For example, if you’re losing weight sustainably and are managing the side effects well (or don’t experience any side effects), then there’s no clinical reason to increase your dose, whatever dose you’re on.

When using GLP-1 medications, it’s not about reaching the highest dose as quickly as possible, but using them to lose weight sustainably and avoid weight regain in the future.

Foundayo starts at 0.8 mg a day, increasing to 2.5 mg after at least 30 days. Further increases are to 5.5 mg, 9 mg, 14.5 mg, and 17.2 mg, with at least 30 days at each dose.¹

Rybelsus starts at 1.5 mg a day for one month, then increases to 4 mg. After at least another month, it can increase to 9 mg if more blood-sugar control is needed.²

Your prescriber can work with you to determine when you can increase your dose based on your progress and side effects. Both medicines are taken as one whole tablet a day.^1,2

Why do the trial doses look higher?

The highest trial doses were equivalent to the current maximum UK tablet doses.

Foundayo’s 36 mg trial capsule has the same effect as its 17.2 mg tablet, while the older 14 mg Rybelsus tablet has the same effect as its current 9 mg tablet.^1,2

The newer tablets are absorbed differently, so you need fewer milligrams for the same effect.

These comparisons apply within each medicine; they don’t provide a way to convert a Rybelsus dose into a Foundayo dose.^1,2

Other medicines and contraception

Some medicines speed up or slow down how our body breaks down Foundayo, changing how much of the drug reaches the bloodstream.

Foundayo can also raise levels of other medicines, so your pharmacist should check prescriptions and supplements before starting it.¹

For example, the antibiotic clarithromycin slows Foundayo’s breakdown. This raises its level in the bloodstream, so the maximum Foundayo dose is limited to 9 mg while they’re taken together.¹

Foundayo raises levels of the active form of simvastatin, a cholesterol-lowering medicine. Its UK instructions are to halve the simvastatin dose.¹

Carbamazepine, used for conditions including epilepsy, and the herbal remedy St John’s wort speed up Foundayo’s breakdown and should be avoided alongside it.¹

Rybelsus can increase absorption of levothyroxine, used for an underactive thyroid, so extra thyroid blood tests may be needed.^1,2

Does Foundayo affect the contraceptive pill?

Foundayo can make the contraceptive pill less effective. It slows stomach emptying, which can affect how other oral medications (like the pill) are absorbed.¹

Add a barrier method, such as condoms, or switch to non-oral contraception for 30 days after starting Foundayo and for 30 days after each dose increase.

Rybelsus doesn’t have this additional instruction with the contraceptive pill, as semaglutide doesn’t seem to impact its absorption in the same way.^1,2

Both medicines are unsuitable during pregnancy and breastfeeding. Foundayo should be stopped at least 3 weeks before a planned pregnancy and Rybelsus at least 2 months beforehand, with a plan for diabetes treatment where needed.^1,2

Starting or switching treatment

If you’re living with type 2 diabetes, but are struggling to keep your blood sugar within the target set by your diabetes team, Foundayo may be an option to switch to if you’re currently on Rybelsus.

In direct comparisons with Rybelsus, Foundayo produced a larger average reduction in HbA1c (average blood sugar levels) and doesn’t need to be taken on an empty stomach.^1,2,3

Before requesting a switch to Foundayo, check your Rybelsus dose and how you’re taking it.

Having food, drink, or other tablets too soon after Rybelsus can reduce its effectiveness, so wait at least 30 minutes before eating or drinking anything to improve effectiveness and may reduce the need to switch to a new medication.²

Still, Foundayo may be easier to fit around shift work, breakfast, or other morning medicines because you can take it any time of day, with or without food.¹

If you’re on Rybelsus for type 2 diabetes and it’s helping you manage your blood sugar levels, then there’s no reason to switch to Foundayo.

ACHIEVE-3 compared people starting one tablet or the other alongside metformin. It didn’t test switching from Rybelsus to Foundayo, so the results can’t predict how much an individual would benefit from changing tablets.³

Before switching, agree with your prescriber when to stop Rybelsus, which Foundayo dose to start, and when to check blood sugar.

If you also take insulin or a sulfonylurea, such as gliclazide, your diabetes team may need to reduce that dose to prevent low blood sugar.^1,2

Can you get Foundayo through the NHS?

You can’t get Foundayo on the NHS yet. However, NICE are currently reviewing whether the medication should be prescribed through the NHS, with a recommendation expected in January 2027.⁶

For diabetes treatment, your NHS diabetes team can check whether Foundayo is on the local prescribing list.

At the moment, most people on Foundayo in the UK will be using a private provider, like Second Nature.

Take home message

Foundayo produced greater average reductions in blood sugar and weight than Rybelsus in adults living with type 2 diabetes. At the highest doses studied, it lowered HbA1c by about 5 mmol/mol more over 52 weeks.³

However, digestive symptoms affected 58% of people taking Foundayo and 45% taking Rybelsus, suggesting that more people experience side effects on Foundayo.

A larger average reduction in blood sugar doesn’t automatically make Foundayo the better treatment for someone already doing well on Rybelsus.³

Still, Foundayo may be easier to maintain as it can be taken with or without food and is also licensed for weight loss. Rybelsus needs to be taken on an empty stomach and is only licensed for type 2 diabetes in the UK.^1,2

Rybelsus also has evidence of reducing serious heart and stroke-related problems in people aged 50 or above living with type 2 diabetes and heart or kidney disease.⁴

If Rybelsus isn’t controlling blood sugar or its fasting instructions are difficult to follow, discuss switching with your prescriber. They’ll need to check other medicines, contraception, and the starting dose before prescribing Foundayo.

Second Nature combines medication support with help from registered nutritionists to plan balanced meals and develop eating habits that fit everyday life.

In our peer-reviewed study of a semaglutide-supported programme, the 135 members still active at 12 months lost an average of 19.1% of their starting weight.⁷

Among all 179 members with a recorded 12-month weight, 77.7% lost at least 10% of their starting weight.⁷

Second Nature's Mounjaro and Wegovy programmes

Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.

Why choose Second Nature over other medication providers, assuming you're eligible?

Because peace of mind matters.

We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.

Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.

At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.

With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.

We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.

Frequently asked questions

Is Foundayo better than Rybelsus for diabetes?

Foundayo lowered HbA1c by about 5 mmol/mol more than Rybelsus over 52 weeks at the highest doses studied.

However, stomach and bowel symptoms affected 58% of people taking Foundayo and 45% taking Rybelsus, so the greater blood-sugar reduction must be weighed against increased side effects.³

Can Rybelsus be prescribed for weight loss?

Rybelsus can support weight loss while treating type 2 diabetes, but it isn’t licensed for weight management in the UK.

Prescribing it for weight loss alone would be outside its approved use.

Foundayo is approved for weight loss in the UK.^1,2

Can you take Foundayo and Rybelsus together?

Taking Foundayo and Rybelsus together isn’t recommended. Both mimic GLP-1, and Foundayo’s U.S. prescribing information advises against combining it with another medicine of this type.⁹

If you’re changing tablets, your prescriber should give you instructions for stopping one and starting the other.

Can you switch straight from Rybelsus to Foundayo?

Your prescriber needs to tell you when to stop Rybelsus, when to start Foundayo, and which dose to use.

There’s no equivalent Foundayo dose for a Rybelsus prescription, so don’t replace your next tablet without those instructions.^1,2

Can you have breakfast with Foundayo?

Yes, you can take Foundayo with breakfast or at any other time, with or without food.

Rybelsus must be taken on an empty stomach, followed by at least 30 minutes without food, drink, or other tablets.^1,2

What happens if you miss a tablet?

For Rybelsus, skip the missed dose and take the next one the following day.

For Foundayo, take the missed dose as soon as possible, but don’t take more than one tablet in a day.^1,2

Can you take either tablet during pregnancy?

Neither should be taken during pregnancy. For a planned pregnancy, stop Foundayo at least 3 weeks beforehand and Rybelsus at least 2 months beforehand, with your prescriber arranging alternative diabetes treatment where needed.^1,2

References

1. Eli Lilly and Company Limited. Foundayo tablets: Summary of Product Characteristics. Updated August 2026. UK prescribing information.
2. Novo Nordisk Limited. Rybelsus 9 mg tablets: Summary of Product Characteristics. UK prescribing information.
3. Rosenstock J, Yabe D, Cox D, et al. Efficacy and safety of once-daily oral orforglipron compared with oral semaglutide in adults with type 2 diabetes (ACHIEVE-3): a multinational, multicentre, non-inferiority, open-label, randomised, phase 3 trial. The Lancet. 2026;407(10534):1147-1160. PMID: 41765029. Trial registration and posted results: NCT06045221.
4. McGuire DK, Marx N, Mulvagh SL, et al. Oral semaglutide and cardiovascular outcomes in high-risk type 2 diabetes. New England Journal of Medicine. 2025;392(20):2001-2012. PMID: 40162642.
5. Klein KR, Wysham C, Tuttle KR, et al. Cardiovascular safety of orforglipron versus insulin glargine in adults with type 2 diabetes at increased cardiovascular risk (ACHIEVE-4): a phase 3, event-driven, randomised, open-label, non-inferiority, active comparator trial. The Lancet. Published online 30 September 2026. PMID: 42815506.
6. National Institute for Health and Care Excellence. Orforglipron for managing overweight and obesity [ID6516]. In development. Accessed 14 October 2026. NICE appraisal.
7. Richards R, Whitman M, Wren G, et al. A remotely delivered GLP-1RA-supported specialist weight management program in adults living with obesity: retrospective service evaluation. JMIR Formative Research. 2025;9:e72577. doi:10.2196/72577.
8. Hudson JL, Wang Y, Bergia RE III, et al. Protein intake greater than the RDA differentially influences whole-body lean mass responses to purposeful catabolic and anabolic stressors: a systematic review and meta-analysis. Advances in Nutrition. 2020;11(3):548-558. Full text.
9. Eli Lilly and Company. Foundayo: U.S. prescribing information. Revised July 2026. Section 1, limitations of use. FDA prescribing information.