What is Foundayo?
Foundayo is the brand name for orforglipron, a once-daily oral GLP-1 receptor agonist tablet developed by Eli Lilly for the treatment of obesity and overweight with weight-related medical conditions. It was approved by the US Food and Drug Administration (FDA) on 1 April 2026 and is the second oral GLP-1 weight loss treatment to receive FDA approval, following the Wegovy tablet (oral semaglutide) in December 2025.
Unlike injectable GLP-1 treatments such as Mounjaro (Tirzepatide) and Wegovy (Semaglutide), Foundayo is a small-molecule, non-peptide compound that is taken as a tablet. This means it can be taken at any time of day without restrictions on food or water intake, offering greater convenience than existing oral and injectable GLP-1 treatments.
Eli Lilly has submitted Foundayo for regulatory approval in more than 40 countries and plans to launch in each market shortly after approval.
How does Foundayo work?
Foundayo works by mimicking the action of glucagon-like peptide-1 (GLP-1), a natural hormone released by the gut after eating. By activating GLP-1 receptors, Foundayo may support weight management through several mechanisms:
- Reducing appetite and food cravings, helping patients feel satisfied with smaller portions.
- Slowing gastric emptying, allowing food to remain in the stomach for longer.
- Helping to regulate blood sugar levels by stimulating insulin release and reducing glucagon secretion.
These are the same core mechanisms through which injectable GLP-1 treatments such as Mounjaro and Wegovy support weight loss. However, Mounjaro additionally activates GIP (glucose-dependent insulinotropic polypeptide) receptors, which may contribute to the greater average weight loss observed in Mounjaro clinical trials compared with GLP-1-only treatments.
How is Foundayo different from Mounjaro?
Foundayo and Mounjaro are both manufactured by Eli Lilly but differ in their formulation, delivery method, mechanism of action and clinical weight loss outcomes.
- Mounjaro (tirzepatide) is a once-weekly injection that acts on both GLP-1 and GIP receptors. In the SURMOUNT-1 clinical trial, patients taking the highest dose of Mounjaro (15mg) lost an average of 22.5% of their body weight over 72 weeks.
- Foundayo (orforglipron) is a once-daily oral tablet that acts on the GLP-1 receptor only. In the ATTAIN-1 Phase 3 trial, patients taking the highest daily dose lost an average of approximately 11% of their body weight over 72 weeks.
Injectable Mounjaro currently demonstrates greater average weight loss in clinical trials. However, Foundayo may be a suitable option for patients who prefer a tablet over injections, those who have difficulty with self-injection or those looking to maintain weight loss achieved through injectable treatment.
How does Foundayo compare to the Wegovy Pill?
Both Foundayo and the Wegovy pill (oral semaglutide) are oral GLP-1 weight loss treatments, but they differ in several important ways.
The Wegovy pill is a peptide-based treatment that must be taken once daily on an empty stomach, with a small amount of water. Patients should avoid eating, drinking or taking other oral medication for at least 30 minutes after taking it.
Foundayo is a non-peptide, small-molecule treatment that can be taken once daily at any time of day, with no restrictions on food or water. This may offer greater convenience and flexibility for patients in their daily routine.
In terms of weight loss results, the Wegovy pill demonstrated an average weight loss of approximately 13.6% over 64 weeks in its Phase 3 trial, whilst Foundayo showed an average weight loss of approximately 11% over 72 weeks at the highest dose.
How is Foundayo taken?
Foundayo is taken as one tablet once a day. The tablet should be swallowed whole and should not be broken, crushed or chewed. It can be taken at any time of day with or without food and with or without water.
Treatment begins at a starting dose of 0.8mg, which is gradually increased over several months to allow the body to adjust and to help reduce gastrointestinal side effects. The recommended dose escalation schedule is:
- Weeks 1 to 4: 0.8mg once daily (starting dose)
- Weeks 5 to 8: 2.5mg once daily
- Weeks 9 to 12: 5.5mg once daily
- Week 13 onwards: the dose may be further increased to 9mg, 14.5mg or 17.2mg once daily, depending on individual response and tolerability
If a dose is missed, it should be taken as soon as possible on the same day. No more than one tablet should be taken per day. Always follow the dosage instructions provided by your prescriber.
How much weight can you lose on Foundayo?
The weight loss achieved with Foundayo has been evaluated in two Phase 3 clinical trials:
- In the ATTAIN-1 trial (adults with obesity or overweight without type 2 diabetes), participants taking the highest dose lost an average of approximately 11% of their body weight (around 25 pounds or 11 kg) over 72 weeks, compared to approximately 2% in the placebo group.
- In the ATTAIN-2 trial (adults with obesity or overweight and type 2 diabetes), participants taking the highest dose lost an average of approximately 10.5% of their body weight (around 23 pounds or 10 kg) over 72 weeks.
- In the ATTAIN-MAINTAIN trial, patients who switched from injectable Wegovy or Mounjaro to Foundayo were able to maintain the majority of their previously achieved weight loss over 52 weeks, whereas the placebo group experienced weight regain.
Individual results may vary depending on factors such as starting weight, dose, adherence, diet and exercise habits and how well the treatment is tolerated.
Can foundayo be used after stopping Mounjaro or Wegovy?
Early clinical evidence suggests that Foundayo may help maintain weight loss achieved after injectable GLP-1 treatment. In the ATTAIN-MAINTAIN trial, participants who had previously completed 72 weeks of treatment with Mounjaro or Wegovy were re-randomised to receive either Foundayo or placebo.
Those who switched to Foundayo maintained the majority of their previously achieved weight loss, whereas the placebo group experienced significant weight regain. This suggests that Foundayo could serve as a convenient oral option for patients who wish to transition from injectable treatment to an oral tablet whilst preserving their weight loss outcomes.
What are the side effects of Foundayo?
The side effect profile of Foundayo observed in clinical trials is consistent with other GLP-1 receptor agonists. The most commonly reported side effects are gastrointestinal and tend to be mild to moderate in severity:
- Nausea
- Constipation
- Diarrhoea
- Vomiting
- Indigestion (dyspepsia)
- Abdominal pain
- Headache
- Bloating (abdominal distension)
- Fatigue
- Belching (eructation)
- Gastro-oesophageal reflux
- Flatulence
- Hair loss
These side effects are generally most pronounced during the dose escalation phase and tend to ease as the body adjusts to the treatment. In the ATTAIN-1 trial, approximately 6 to 10% of participants discontinued treatment due to gastrointestinal adverse events at higher doses, compared with approximately 4% in the placebo group.
When will Foundayo be available in the UK?
Foundayo is not yet approved or available in the UK. Following its FDA approval on 1 April 2026, Eli Lilly has confirmed that regulatory submissions have been made in more than 40 countries. In the UK, the MHRA would need to evaluate and approve the drug before it could become available.
The MHRA has established reliance procedures that allow it to consider assessments conducted by comparable regulators such as the FDA, which could support a faster review timeline. Based on typical regulatory timelines and the precedent set by other GLP-1 treatments, UK availability could be expected in late 2026 or early 2027.
How much will Foundayo cost in the UK?
UK pricing for Foundayo has not yet been confirmed, as the product has not received MHRA marketing authorisation.
UK private market pricing will depend on the MHRA approval timeline, manufacturing costs and the competitive landscape with existing injectable treatments such as Mounjaro and Wegovy. As a small-molecule tablet, Foundayo is generally simpler and less expensive to manufacture than peptide-based injectable treatments, which may support more competitive pricing over time.
Where can I buy Foundayo in the UK?
Foundayo is not yet available for purchase in the UK, as it is pending MHRA regulatory approval. Any website currently offering to sell Foundayo or orforglipron in the UK should be approached with caution, as the product is not yet licensed for UK sale.
Once approved for use in the UK, Foundayo is expected to become available through GPhC-regulated pharmacies. You can sign up above to receive updates as soon as Foundayo becomes available at Pharmica.
What weight loss treatments are currently available?
While Foundayo is not yet available in the UK, several weight loss treatments are currently available through Pharmica:
Sources:
- FDA: Approves First New Molecular Entity Under National Priority Voucher Program. [Accessed 8th April 2026]
- Eli Lilly: FDA approves Lilly's Foundayo (orforglipron), the only GLP-1 pill for weight loss that can be taken any time of day without food or water restrictions. [Accessed 8th April 2026]
- Eli Lilly: Foundayo (orforglipron) prescribing information and patient site. [Accessed 8th April 2026]
- Wharton S, et al. Orforglipron, an Oral GLP-1 Receptor Agonist for Obesity Treatment, New England Journal of Medicine, 2025. [Accessed 8th April 2026]
- Horn DB, et al. Orforglipron, an oral small-molecule GLP-1 receptor agonist, for the treatment of obesity in people with type 2 diabetes (ATTAIN-2), The Lancet, 2025. [Accessed 8th April 2026]