What to Expect When Starting Foundayo

What happens when you start Foundayo?

You begin on the lowest dose of 0.8mg daily and stay there for at least 30 days. Foundayo (orforglipron) is a daily pill licensed in the UK for weight management in adults. Beginning Foundayo at the lowest strength gives your digestive system time to adjust.

Foundayo dosing schedules run through six strengths, with a minimum of 30 days on each before titration (moving up through the doses).

What happens	When
You start on 0.8mg, the lowest dose	Day 1
Nausea, vomiting and diarrhoea are most likely	While your dose is going up
Your dose can move to 2.5mg	After at least 30 days
Then 5.5mg, then 9mg, then 14.5mg	After at least 30 days on each
You reach 17.2mg, the maximum dose	Around five months in, at the earliest
Average weight loss measured in ATTAIN-1	At 72 weeks

You can move up once you have completed at least 30 days on your current strength and feel ready for the next one. The maximum dose is 17.2mg a day.

Your dosage does not have to reach 17.2mg to be doing its job. You can reasonably stay on a dose for longer than one month if it is working comfortably. 

How do you take Foundayo when you start?

You take one tablet a day, with or without food, at any hour that suits you. Unlike with Wegovy tablets, you do not need an empty stomach. Pick whichever time you will actually remember. Swallow the tablet whole rather than breaking, crushing or chewing it.

Oral contraception, including the combined pill, may not work as reliably during your first days on the treatment. Foundayo’s Foundayo’s UK product information advises switching to a non-oral method such as an injection, patch or coil. Adding a barrier method is the alternative. Either option needs to cover the 30 days after you start and the 30 days after each dose increase.

If you miss a dose, take it as soon as you can and carry on as normal the next day. Do not take two tablets in one day to make up for a missed one, and do not use two smaller tablets to reach a higher strength. Get in touch with us if you have missed a full week or more, because your starting point may need reviewing.

What should you expect in your first week on Foundayo?

Your Foundayo first week is unlikely to show much on the scales, and that is normal. The 0.8mg starting strength sits below the maintenance doses tested for weight loss in ATTAIN-1. Its job is to get you onto the medicine comfortably.

Stomach emptying slows most sharply after that first tablet, then the effect fades with repeated dosing. Meals can therefore sit heavier in your opening days than they will later, even though the dose has not changed.

What are the most common side effects when you start Foundayo?

Feeling sick is the most common side effect of Foundayo. Around a third of people reported nausea in the ATTAIN-1 trial trial. Roughly one in ten people given a placebo, or inactive pill, reported the same. Constipation, diarrhoea and vomiting followed a similar pattern.

Side effect	5.5mg	9mg	17.2mg	Placebo
Nausea	28.9%	35.9%	33.7%	10.4%
Constipation	21.7%	29.8%	25.4%	9.3%
Diarrhoea	21.0%	22.8%	23.1%	9.6%
Vomiting	13.0%	21.4%	24.0%	3.5%

ATTAIN-1 tested orforglipron as capsules. The strengths above are the equivalent licensed tablet doses set out in the Foundayo product information.

Reports of nausea and other stomach effects clustered around dose increases, then became less frequent over time. Under 4% of those events counted as severe, though between 3.7% and 6.8% of people stopped Foundayo because of them. 

Hair loss affected 3.7% of people taking orforglipron and 1.8% of those on placebo. The hair loss was temporary, and tended to happen alongside the weight loss. Headache, dizziness, tiredness, reflux and gallstones also sit on the UK list of common reactions.

Month two and beyond on Foundayo: what should you expect?

Month two brings your first dose increase, to 2.5mg, and the same 30-day pattern repeats through each strength. Nausea, vomiting and diarrhoea happen more often while your dose is going up. They then become less frequent once you settle on it.

Appetite is harder to put a date on, because ATTAIN-1 measured weight rather than the timing of appetite changes. What the medicine does is reduce how much food you want. That can happen before anything shows on the scales. You might find you cannot finish a plate you would normally clear, or that you stop reaching for an evening snack. 

ATTAIN-1 recorded larger average weight loss at each higher maintenance strength over 72 weeks.

When will you start losing weight on Foundayo?

ATTAIN-1 measused average weight loss at 72 weeks, close to a year and a half. 

Foundayo dose	Average weight loss at 72 weeks
5.5mg	7.5%
9mg	8.4%
17.2mg	11.2%
Placebo	2.1%

For someone starting at 103kg, the average trial weight loss of 11.2% is roughly 11.5kg down. The table averages include people who stopped taking Foundayo partway through. The UK product information for Foundayo reports 12.4% at 17.2mg, which estimates what would happen if everyone stayed on treatment for the full 72 weeks.

Individual results vary, and your first eight weeks will look modest against a year and a half of treatment. Participants also followed a balanced, healthy diet and stayed active throughout.

A Foundayo beginner’s guide: how can you make the first few weeks easier?

• Eat smaller portions and stop when you feel full, rather than finishing the plate out of habit.
• Sip fluids steadily through the day, because nausea, vomiting and diarrhoea can lead to dehydration. Severe dehydration can affect how well your kidneys work.
• Go easy on alcohol. The NHS advises avoiding it on semaglutide, a similar GLP-1 medicine, because it makes nausea worse. 
• Tell us about every medicine you take. If you already take simvastatin, your GP should halve the dose. Some antibiotics, such as clarithromycin, cap your Foundayo dose at 9mg.
• Tell your hospital team you take Foundayo before any operation or sedation. Foundayo can slow how quickly your stomach empties, which matters when you are sedated.

When should I see a doctor?

Speak to our clinical team about mild digestive side effects that you are able to manage at home. Reach out if you have any questions about whether to increase your dose, stay where you are, or pause.

Contact your GP or call NHS 111 the same day if you notice:

• Yellowing of your skin or eyes, or severe pain in the upper right of your abdomen, which can point to gallbladder problems
• Vomiting or diarrhoea so persistent that you cannot keep fluids down for more than six hours
• Sweating, shaking, a fast heartbeat or confusion, which can be signs of low blood sugar. This matters especially if you also take insulin or a sulfonylurea
• Severe constipation that will not shift, or abdominal pain with bloating and no bowel movement

Stop Foundayo and call 999 or go to A&E if you notice any of the following:

• Severe abdominal pain spreading to your back that does not go away, which can signal inflammation of the pancreas
• Sudden loss of vision, including partial loss in one eye
• Swelling of your face, lips, tongue or throat, or difficulty breathing
• Signs of severe dehydration such as passing little urine, extreme thirst or feeling faint

Frequently asked questions

How does Foundayo work?

Foundayo works by copying the action of GLP-1, a hormone your gut releases after you eat to tell your brain you have had enough. Orforglipron is a small molecule rather than a copy of the hormone itself. It acts on the areas of the brain controlling appetite. Hunger and food cravings both ease, and slowed stomach emptying keeps you full for longer after eating.

Does Foundayo have FDA approval as well?

Foundayo received approval by the Food and Drug Administration (FDA) in the United States in April 2026. This happened several months ahead of its UK license.

Why does US information about Foundayo mention thyroid cancer?

The US safety label warns that other GLP-1 medicines caused thyroid tumours in rats. It tells anyone with a personal or family history of medullary thyroid cancer not to take Foundayo.

Orforglipron did not cause those tumours in animal studies. In the UK, the only reason not to take Foundayo is an allergy to orforglipron or anything else in the tablet, or if there are any contraindications to your medical history and this is not suitable for you.

Who is Foundayo licensed for in the UK?

Foundayo is licensed for adults with obesity, meaning a BMI of 30 or above. It also covers adults with a BMI between 27 and 30 who have a weight-related condition. High blood pressure, sleep apnoea and type 2 diabetes all qualify. A separate licence covers blood sugar control in adults with type 2 diabetes.

How does Foundayo compare with the other oral options and with weekly injections?

Foundayo and the Wegovy pill from Novo Nordisk are the two licensed oral options for weight management in the UK. Weekly injections such as Wegovy and Mounjaro remain the alternative. 

Foundayo can be taken at any time of day, with or without food. The Wegovy pill needs an overnight fast, and injections need a weekly needle.

Can I get Foundayo on the NHS?

Foundayo is not currently available on the NHS. The National Institute for Health and Care Excellence, known as NICE, decides whether the NHS should fund a treatment. NICE expects to publish its guidance on orforglipron on 18 November 2026.

Key takeaways

• The bottom line: your first month is one 0.8mg tablet a day, and that month is about tolerance rather than weight loss.
• You can take Foundayo at any hour, with or without food.
• Stomach and bowel side effects peak while your dose is going up, then become less frequent over time.
• Tips for starting Foundayo: eat smaller portions, stay well hydrated, and tell us about other medicines or planned procedures.
• What to expect: Foundayo works over months rather than weeks. Adults with obesity or overweight lost around 11% of their body weight over 72 weeks at the highest dose.

References

Foundayo 17.2 mg film-coated tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 31 August 2026].

UK first in Europe to authorise orforglipron for weight management and type 2 diabetes, Medicines and Healthcare products Regulatory Agency, 2026 [Accessed 31 August 2026].

Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment, New England Journal of Medicine, 2025 [Accessed 31 August 2026].

Complete ATTAIN-1 results published in The New England Journal of Medicine, Eli Lilly and Company, 2025 [Accessed 31 August 2026].

Wegovy 25 mg tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 31 August 2026].

Semaglutide: a medicine to manage type 2 diabetes or treat obesity, NHS, 2026 [Accessed 31 August 2026].

Orforglipron for managing overweight and obesity [ID6516], National Institute for Health and Care Excellence, 2026 [Accessed 31 August 2026].

Foundayo (orforglipron) tablets: Highlights of Prescribing Information, U.S. Food and Drug Administration, 2026 [Accessed 31 August 2026].

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, Eli Lilly and Company, 2026 [Accessed 31 August 2026].

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