Foundayo (Orforglipron) vs Wegovy Pill UK: Which Weight Loss Tablet Is Better?

For the first time, two different daily GLP-1 tablets have been authorised in the UK for weight management. Foundayo (orforglipron) was licensed on 10 August 2026, following the authorisation of Wegovy tablets (oral semaglutide) on 11 June 2026. They are both daily tablets and both GLP-1 medicines — and that is roughly where the similarity stops.

✍️ Written by Shadeia Younis, Superintendent Pharmacist (GPhC No. 2052119) and the Slinic Clinical Team
Last medically reviewed: 15th August 2026 · Clinical content verified against the UK Summary of Product Characteristics for Foundayo (electronic Medicines Compendium, 14 August 2026) and for Wegovy tablets (eMC, 16 June 2026)

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At a glance

Why one needs a fasting protocol and the other doesn’t

This is the root of every practical difference between them, and it’s worth two minutes to understand.

Semaglutide is a peptide — a protein-based molecule. Proteins are what your digestive enzymes are built to destroy, which is why semaglutide was an injection for years. The Wegovy pill gets around this by pairing it with an absorption enhancer called SNAC, which protects the molecule in the stomach long enough for a little of it to cross into the bloodstream. Even so, the estimated absolute bioavailability is only around 1–2%, and absorption is reduced by food and by larger volumes of water.

Orforglipron is not a peptide. It is a small, chemically synthesised non-peptide molecule that activates the same GLP-1 receptor but survives digestion on its own. Its absolute bioavailability was around 77% after a 1 mg capsule dose, decreasing at higher doses. A high-fat meal reduced exposure by only around 4% to 19%, which is why the SmPC states it can be taken with or without food.

What each looks like in an actual day

If none of those rows describe you, the routine difference may not matter much. If two or three do, it probably matters more than a percentage point of trial efficacy.

What the weight-loss trials found

These come from separate trials. Different populations, different durations, different protocols — so the comparison is indicative rather than definitive.

In ATTAIN-1, at the maximum dose, 77.1% of participants lost at least 5% of their body weight, 59.6% lost at least 10%, and 20.1% lost at least 20%. The corresponding placebo figures were 22.1%, 8.6% and 1.6%. Mean weight change was −12.4% with the highest orforglipron dose versus −0.9% with placebo.

The honest reading: numerically, oral semaglutide produced the larger mean reduction in these separate trials, but the studies cannot establish that one treatment causes greater weight loss than the other. The numerical difference is around one percentage point, and differences in study duration, participants and trial design mean it should not be interpreted as a treatment difference.

The one direct comparison — and its catch

Unusually for two newly launched medicines, a head-to-head trial does exist. ACHIEVE-3 randomised 1,698 people with type 2 diabetes to orforglipron or oral semaglutide over 52 weeks, both alongside metformin.

What ACHIEVE-3 does show is that orforglipron has substantial glucose-lowering and weight-reducing efficacy when compared directly with the oral semaglutide doses studied. It cannot tell us how Foundayo compares with Wegovy 25 mg for weight management.

Dose ladders

Both titrate upward from a low starting dose to limit gastrointestinal side effects, but the numbers look nothing alike — and there is no conversion between them, because they are different molecules.

Foundayo has six strengths: 0.8, 2.5, 5.5, 9, 14.5 and 17.2 mg. You start at 0.8 mg, and after at least 30 days the dose should be increased to 2.5 mg. Further increases follow at intervals of at least 30 days, according to response and tolerability, to a maximum of 17.2 mg once daily. Our full doses guide covers the schedule and the medicines that cap it at 9 mg.

The Wegovy pill titrates 1.5 mg → 4 mg → 9 mg → 25 mg, with a minimum of one month at each dose level. The 25 mg dose is the maintenance dose, although the previous level can be maintained if needed. Note that this is the weight-management ladder, which differs from the diabetes-dose ladder you may also see quoted.

Side effects

Both share the GLP-1 class profile: predominantly gastrointestinal, worst during titration, settling over time. No head-to-head trial has compared their tolerability for weight management, so “which is gentler” cannot be answered from evidence.

For Foundayo specifically, gastrointestinal effects occurred in 68.7% of people at the highest dose against 36.3% on placebo, and were mostly mild or moderate. Between 3.7% and 6.8% of people stopped because of them across the doses studied. Our side effects guide sets out the full frequency tables.

One practical difference is that the Wegovy tablet must be taken after an extended fasting period, whereas Foundayo can be taken at another time of day if that fits better.

Other medicines

This is where Foundayo is the more complicated of the two, and it deserves stating plainly rather than being buried.

Orforglipron is a substrate of CYP3A4 and CYP2J2, and of P-gp, OATP1B1 and OATP1B3. In practice that means:

• A strong CYP3A4 inhibitor or an OATP1B inhibitor caps your licensed maximum at 9 mg once daily
• Ritonavir and telaprevir should be avoided altogether
• Strong CYP3A4 inducers — rifampicin, phenytoin, St John’s wort — should also be avoided
• The simvastatin dose should be halved when taken with orforglipron

The Wegovy pill’s interaction concerns run differently, centring on the absorption window and what else you take in the morning. Whichever you’re considering, bring your complete medication list to assessment — prescriptions, over-the-counter medicines, herbal products and supplements.

There is also an important difference around oral contraception. Foundayo may reduce the effectiveness of oral hormonal contraceptives, so its SmPC advises switching to a non-oral method or adding a barrier method for 30 days after starting and for 30 days after every dose increase. The Wegovy tablet SmPC, by contrast, reports no clinically relevant change in exposure to the oral contraceptives studied.

Factors a prescriber may consider when comparing Foundayo and Wegovy tablets

• You take morning medicines that can’t be delayed — levothyroxine is the obvious one
• You work shifts or wake at irregular times
• You fast for religious reasons
• You’ve tried the Wegovy pill and found the protocol unworkable in practice
• You travel frequently across time zones
• You know yourself well enough to know a 30-minute morning window won’t survive contact with your actual mornings

Factors a prescriber may consider with oral semaglutide

• You already have a settled early-morning routine and the protocol genuinely fits it
• You’ve done well on semaglutide before, by injection, and would rather stay with a molecule you know suits you
• You take a medicine that would cap Foundayo at 9 mg and you want access to a full dose range
• Previous experience with semaglutide may be relevant, as semaglutide has a longer history of clinical use than orforglipron
• Availability. Foundayo is newly licensed and supply is still establishing

Neither list replaces an individual assessment, and neither is a recommendation. They set out factors a prescriber may weigh when considering which treatment is appropriate for an individual.

Switching between the two

Some patients may consider switching between oral semaglutide and Foundayo because their administration requirements differ considerably.

The rules are the same as any GLP-1 switch. There is no dose-for-dose conversion. You should not deliberately take two GLP-1 receptor agonists together. And the timing between stopping one and starting the other is a prescriber decision, not something to work out yourself.

One thing in your favour if you’re going this direction: because Foundayo has no fasting window, the switch usually makes your daily routine simpler rather than more complicated — which is the opposite of most medicine changes.

Frequently asked questions

1. Which works better for weight loss?

On separate weight-management trials, oral semaglutide 25 mg produced 13.6% average reduction over 64 weeks and orforglipron 12.4% over 72 weeks. Those are different trials, so the comparison is indicative. No head-to-head trial has compared them at their weight-management doses.

2. Didn’t a study compare them directly?

ACHIEVE-3 did, in people with type 2 diabetes, and orforglipron produced greater weight reduction and a larger HbA1c reduction. But it used the diabetes doses of oral semaglutide — 7 mg and 14 mg — not the 25 mg weight-management dose. It doesn’t settle the weight-loss comparison.

3. Do I really have to fast for the Wegovy pill?

Yes — it’s what makes the medicine absorb. A fast of at least 8 hours, then an empty stomach, no more than 120 ml of plain water, and at least 30 minutes before eating, drinking or taking other oral medicines. Skipping it doesn’t just reduce the effect; it undermines the mechanism.

4. Can I take Foundayo with breakfast?

Yes. The SmPC states it can be taken once daily at any time of day, with or without food, and with no water restriction.

5. Are the tablets as effective as Mounjaro?

Not on the separate pivotal trial results. Tirzepatide 15 mg produced around 20.9% mean weight reduction at 72 weeks in SURMOUNT-1, compared with 13.6% for oral semaglutide 25 mg in OASIS 4 and 12.4% for the highest orforglipron dose in ATTAIN-1. These were separate trials rather than head-to-head comparisons.

6. Which has fewer side effects?

No head-to-head trial has compared their tolerability for weight management, so that can’t be answered from evidence. Both share the GLP-1 class profile, which is predominantly gastrointestinal.

7. Can I switch from one to the other?

Under prescriber supervision, yes. There is no dose-for-dose conversion between them and you should not deliberately take both. Your starting dose and timing should be decided by the prescriber based on what you are leaving, your current dose, treatment history and tolerability.

8. Is 17.2 mg of Foundayo stronger than 14 mg of the Wegovy pill?

The numbers aren’t comparable. They are different molecules with different potencies, so milligrams don’t translate between them.

9. Does either need refrigeration?

No. Both are tablets stored at room temperature, which is a practical advantage over the injections for travel.

10. Are either available on the NHS?

Foundayo is not — MHRA authorisation and NHS funding are separate processes, and the NICE assessment has not concluded. Check current NHS guidance for the Wegovy pill, as its position may have moved since it was licensed in June 2026.

11. Which is better if I take levothyroxine?

Foundayo does not have the Wegovy tablet’s required fasting administration window, which may simplify dosing if you also take levothyroxine. With oral semaglutide, the SmPC additionally reports a 33% increase in total thyroxine exposure when levothyroxine was co-administered, and says thyroid-parameter monitoring should be considered. Thyroid replacement requirements can also change as weight changes, so either way that needs monitoring.

12. Which should I choose?

That’s a decision for you and your prescriber. What can be said generally: the trial numbers are close enough that the daily routine, your other medicines and your own honest assessment of what you’ll keep to are likely to matter more than the efficacy difference.

Summary

Two daily tablets, two different molecules, similar trial results and completely different daily demands. Numerically, oral semaglutide produced the larger mean reduction across the separate weight-management trials, by around a percentage point — but those trials cannot establish a treatment difference. The one direct comparison used diabetes doses, so it doesn’t settle it either.

Where they genuinely differ is the routine. Foundayo does not require a fasting window. The Wegovy pill asks for a fast of at least 8 hours, an empty stomach, a measured amount of water and half an hour before anything else — every day, indefinitely.

That is not a small thing over a year of treatment, and it’s the difference most likely to determine which one actually works for you.

Related guides

• Foundayo (Orforglipron) UK — the complete guide to the oral GLP-1 tablet.
• Wegovy Pill UK — the complete guide to oral semaglutide.
• Foundayo Doses — the titration schedule and dose caps.
• Foundayo Side Effects — full frequency tables and what needs urgent attention.
• Switching from Mounjaro to Foundayo — what the evidence actually shows.
• Weight Loss Injections UK — the full overview of treatment options.
• Slinic Weight Loss Clinic — start an assessment.

References

1. Foundayo 17.2 mg film-coated tablets — Summary of Product Characteristics. Eli Lilly and Company Limited. electronic Medicines Compendium, last updated 14 August 2026. medicines.org.uk
2. MHRA — UK first in Europe to authorise orforglipron for weight management and type 2 diabetes. GOV.UK, 10 August 2026.
3. Wegovy 25 mg tablets — Summary of Product Characteristics. Novo Nordisk A/S. electronic Medicines Compendium, last updated 16 June 2026. medicines.org.uk/emc/product/102347/smpc
4. Wharton S, Aronne LJ, Stefanski A, et al. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment. N Engl J Med. 2025;393(18):1796–1806. doi:10.1056/NEJMoa2511774
5. Wharton S, Lingvay I, Bogdanski P, et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity (OASIS 4). N Engl J Med. 2025;393(11):1077–1087. doi:10.1056/NEJMoa2500969
6. ACHIEVE-3 — orforglipron compared with oral semaglutide in adults with type 2 diabetes on metformin, as reported in the Foundayo Summary of Product Characteristics, section 5.1.
7. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205–216. doi:10.1056/NEJMoa2206038
8. MHRA Yellow Card scheme — report suspected side effects. yellowcard.mhra.gov.uk