In the Phase 3 ATTAIN-1 trial, participants taking the 36mg dose of orforglipron lost on average 12.4% of their body weight over 72 weeks, alongside lifestyle counselling. Individual results vary; not everyone reaches this.
Orforglipron (brand name Foundayo) is a once-daily GLP-1 tablet. Below we explain what the ATTAIN-1 result actually means, how it compares in context with other options, and how to set realistic expectations.
What the ATTAIN-1 trial measured
ATTAIN-1 was the Phase 3 clinical trial studying orforglipron for weight management. Participants received the medicine alongside lifestyle counselling — meaning dietary and activity support formed part of the programme, not the tablet alone.
The headline figure is an average. Some people in a trial lose considerably more than the average and some lose less, which is why the average is only ever a guide to what a group achieved, not a promise for any one person.
Citation: Eli Lilly Phase 3 ATTAIN-1 (2026), published in the New England Journal of Medicine.
How much weight did people lose on orforglipron?
To restate clearly: on the 36mg dose over 72 weeks, average weight loss was 12.4%. Individual results vary; not everyone reaches this.
For a person weighing 100kg, 12.4% represents around 12kg over roughly 16–17 months of treatment — a meaningful reduction, but one that builds gradually rather than in the first few weeks.
It is worth understanding why the figure is what it is. Orforglipron is a small-molecule GLP-1 receptor agonist, meaning it activates a single gut-hormone pathway that helps control appetite. That is a different design from a medicine acting on two receptors, and trial results reflect these differences.
Putting 12.4% in context
Trial percentages are easy to compare at a glance but hard to compare fairly. Different trials enrol different people, run for different lengths of time and use different doses, so these numbers are not head-to-head comparisons.
With that caveat firmly in place, here is what the trials we can reference reported:
| Medicine | Trial & dose | Average weight loss | Duration |
|---|---|---|---|
| Orforglipron (Foundayo) | ATTAIN-1, 36mg | 12.4% | 72 weeks |
| Wegovy Tablet (oral semaglutide) | OASIS 4, 25mg | 16.6% | 64 weeks |
| Wegovy injection (semaglutide) | STEP UP, 7.2mg | 20.7% | 72 weeks |
| Mounjaro (tirzepatide) | SURMOUNT-1, 15mg | 22.5% | 72 weeks |
Individual results vary; not everyone reaches these figures. These are cross-trial figures included for context only — they were not measured against each other in a single study, so they cannot tell you which medicine would suit you.
Why orforglipron is of interest
Orforglipron is a small-molecule GLP-1 receptor agonist designed to survive digestion, so it is taken as an ordinary once-daily pill — any time of day, with or without food or water.
That is a notable practical difference. The other GLP-1 tablet, the Wegovy Tablet, must be taken first thing on an empty stomach with a small sip of plain water, then followed by a 30-minute wait before eating, drinking anything else or taking other medicines — because taken with food it is far less effective. Orforglipron does not carry that timing restriction.
Its UK status — and our position
Orforglipron was approved by the US FDA on 1 April 2026, and the MHRA granted a UK marketing authorisation on 10 August 2026 for weight management and type 2 diabetes — the first approval of this GLP-1 tablet in Europe.
A marketing authorisation permits a medicine to be prescribed in the UK; it does not mean any particular pharmacy stocks it. We do not supply orforglipron yet, and we intend to offer it once we are able to obtain it.
There is no published UK price for orforglipron, and NHS funding is a separate decision made by NICE — no timetable for that has been confirmed. Rather than estimate, we would rather say so plainly. You can read a factual overview on our Foundayo reference page.
Setting realistic expectations
Whichever medicine you and a prescriber consider, a few principles apply to everyone:
- Averages are not targets. The 12.4% figure describes a group over 72 weeks — your result may be higher or lower.
- Lifestyle support matters. In the trials, medicine was combined with dietary and activity counselling; the tablet is not a standalone fix.
- Weight loss is gradual. These figures reflect more than a year of treatment, not a quick result.
- Suitability is individual. A medicine is only appropriate after a clinical assessment.
Side effects to be aware of
As a GLP-1 medicine, orforglipron shares the class side-effect profile seen with other GLP-1 treatments. The most common effects reported with this class are gastrointestinal — such as nausea, diarrhoea, constipation and vomiting — along with decreased appetite and fatigue, and these are often most noticeable early on.
Rarer but serious effects across the GLP-1 class can include severe allergic reactions and pancreatitis. Any medicine in this group is a Prescription-Only Medicine and should only be used under professional supervision.
If you ever experience side effects from a medicine, you can report them through the MHRA Yellow Card scheme at https://yellowcard.mhra.gov.uk/.
Who these treatments are generally for
UK eligibility for weight-management medicines is typically for adults aged 18 and over with a BMI of 30 or more, or a BMI of 27–30 alongside a weight-related condition such as type 2 diabetes, high blood pressure or sleep apnoea.
They are not suitable for everyone — for example if you are pregnant, planning pregnancy or breastfeeding, have type 1 diabetes, a personal or family history of medullary thyroid cancer or MEN2, a history of pancreatitis, severe gastrointestinal disease, an active eating disorder, severe liver or kidney impairment, or a known allergy to the active ingredient.
What you can do now
While orforglipron is not something we currently supply, licensed alternatives are available now, including two GLP-1 tablets and two once-weekly injections. You can compare them on our treatments overview or the combined weight-loss injections page.
A treatment is only ever prescribed if it is clinically appropriate for you after a free online consultation with a GPhC-registered prescriber — it is never guaranteed. You can start that free eligibility check at start a consultation, or read more about The Weight Clinic.
This article is for information only and is not a substitute for personalised medical advice. Weight-loss medicines are prescription-only, are not suitable for everyone, and are prescribed only after a clinical consultation with a GPhC-registered prescriber. Individual results vary. Always speak to a UK-registered pharmacist or doctor before starting or changing any prescription medication.
