What the evidence says
The only contraindication in the UK Foundayo licence is an allergy to orforglipron or another ingredient in the tablet. Gallbladder disease and not having a gallbladder aren’t on that list.1
The licence doesn’t say that people without a gallbladder have the same safety profiles as everyone else. It gives no special dose instruction for this group because the trials didn’t report a separate analysis for them.1,2
Not having a gallbladder isn’t considered a reason not to prescribe Foundayo, but a clinician still needs to assess whether it’s suitable for you.
Absorption without a gallbladder
The gallbladder stores and concentrates bile, a fluid the liver makes that helps digest fat. Without a gallbladder, bile continues to flow from the liver into the small intestine, but it isn’t stored and released with meals.
Foundayo can be taken at any time of day, without restrictions on food or water. Studies in the general trial population found that food didn’t change absorption enough to affect how the tablet is taken.1
The food studies support the standard instructions for Foundayo, but they didn’t test absorption in people without a gallbladder.
The official prescribing information doesn’t give different instructions for people without a gallbladder. A prescriber can monitor how well Foundayo works and whether you tolerate the dose.
Gallstones and bile-duct problems
In Foundayo’s weight-management trials, 1.3% of people taking the medication reported gallstones, compared with 0.6% taking placebo. That’s equivalent to about 13 people in every 1,000 taking Foundayo, compared with six in every 1,000 taking placebo: seven additional cases per 1,000.1
An analysis that pooled 76 trials involving more than 100,000 people found that gallbladder or bile-duct disease was 37% more likely with GLP-1 medications, the family of appetite-reducing medicines that includes Foundayo, than in the comparison groups. The increase was larger in weight-loss trials and with higher doses or longer treatment.3
This increased risk isn’t due to the medications per se, but typically to how fast individuals are losing weight, as weight loss can change bile composition and make gallstones more likely.
Still, GLP-1 medications may also reduce how well the gallbladder empties, so the evidence doesn’t support attributing the risk to weight loss alone.3
Without a gallbladder, new gallbladder stones and gallbladder inflammation can’t develop. However, stones can remain in the bile ducts after surgery, and bile-duct problems can still cause pain, jaundice, infection, or inflammation of the pancreas, called pancreatitis.6
If you’ve had gallstone pancreatitis before, tell the prescriber even if you no longer have a gallbladder. Foundayo hasn’t been studied in people with a history of pancreatitis, and the official prescribing information advises caution.1
How a prescriber assesses you
There’s no fixed time you need to wait to start Foundayo after gallbladder removal. Your prescriber needs to know when the gallbladder was removed, whether recovery is complete, and whether digestive or biliary symptoms continue.
| Situation |
How it affects the assessment |
What to do |
| Recovered from surgery with no ongoing symptoms |
Not having a gallbladder isn’t an automatic barrier |
Tell the prescriber that you don’t have a gallbladder, why it was removed, and when |
| Recent surgery or recovery is continuing |
There’s no licence-based wait, but starting may be delayed until recovery is established |
Ask the surgical team and Foundayo prescriber to review the timing |
| Persistent watery or urgent diarrhoea |
Bile acid diarrhoea may be present before Foundayo is started |
Ask the GP to assess the symptoms so there’s a clear baseline |
| Previous gallstone pancreatitis or bile-duct stones |
The history affects the individual risk assessment |
Give the prescriber the diagnosis, treatment, and dates |
| Current severe pain, jaundice, fever, or repeated vomiting |
These symptoms need medical assessment before a prescribing decision |
Contact NHS 111 or seek urgent medical help |
Some private providers use their own screening rules, which can be stricter than the official UK prescribing information. If one provider doesn’t prescribe you Foundayo, it means you don’t meet that provider’s criteria. It doesn’t mean Foundayo can’t be prescribed to anyone without a gallbladder.
Answer screening questions honestly and say that you don’t have a gallbladder, even if a form asks only about current gallbladder problems. A GP or another qualified prescriber may reach a different decision after reviewing the full medical history.
Digestive side effects
Nausea, constipation, diarrhoea, vomiting, indigestion, and abdominal pain are all very common Foundayo side effects.
Across the weight-management trials, digestive side effects affected 60.1% to 68.7% of people taking Foundayo, compared with 36.3% taking placebo.1
Most were mild or moderate, and nausea, vomiting, and diarrhoea were more frequent as the dose increased before becoming less common over time.1
The trials didn’t report digestive side effects separately for people without a gallbladder. These symptoms can overlap with digestive changes that were already present after surgery, making the cause harder to identify.
Foundayo starts at 0.8 mg once a day, and each increase is separated by at least 30 days. The next increase depends on side effects and progress, so tell the prescriber about side effects you’re experiencing before the dose review.1
- Eat three balanced meals a day
- Drink regularly, particularly during diarrhoea or vomiting
- Record when symptoms began and whether they changed after a dose increase
- Tell the prescriber about ongoing symptoms rather than increasing the dose without discussing them
Bile acid diarrhoea
Without a gallbladder, more bile acids can reach the large intestine, draw in water, and speed up bowel movements. This is called bile acid diarrhoea, and it usually causes watery or urgent diarrhoea that can be mistaken for a side effect of Foundayo.
A UK audit included 9,439 people who had gallbladder surgery, but only 202 were tested for bile acid diarrhoea. Among this small group, 62.8% had the condition.4
Testing was mainly carried out in people with symptoms, so this figure doesn’t show how common bile acid diarrhoea is among everyone without a gallbladder.
Ask your GP about bile acid diarrhoea if watery or urgent diarrhoea began after surgery, was present before Foundayo, or continues despite being on a stable dose.
Taking Foundayo with colestyramine
Colestyramine is a powder used to treat bile acid diarrhoea. Because it stays inside the gut and traps bile acids, it can also trap other medicines taken by mouth and reduce how much is absorbed.
The Questran instructions therefore say to take other medicines at least one hour before colestyramine or four to six hours afterwards.5
Foundayo and colestyramine haven’t been studied together, and the Foundayo prescribing instructions don’t list a specific interaction.
The advice to separate the medicines comes from the colestyramine instructions. Colestyramine can trap other medicines in the gut and reduce absorption, but this doesn’t mean a Foundayo-specific interaction has been found.5
Ask a pharmacist to plan the full schedule, especially if you take colestyramine more than once a day or alongside several other oral medicines. The pharmacist can separate every oral medicine from colestyramine, not only Foundayo.
Eating well without a gallbladder
After recovering from gallbladder surgery, most people can eat the same healthy diet as before. A large amount of fat in one meal can still cause diarrhoea, bloating, or urgency for some people, especially early in recovery.6
Most people don’t need to avoid fat altogether. If a large portion triggers symptoms, try a smaller amount across three balanced meals and adjust it based on what you tolerate. Whole-food sources include extra virgin olive oil, nuts, avocado, eggs, full-fat yoghurt, and oily fish.
We recommend eating a diet based on whole foods that contains enough protein, fibre, fat, and complex carbohydrates, and limits ultra-processed foods.
A useful guide is the Second Nature balanced plate: half vegetables, a quarter protein, a quarter complex carbohydrates such as wholegrain bread, oats, brown rice, or potatoes, plus a serving of fat.
Foundayo reduces hunger and food noise, which can make it harder to eat enough protein. Aim for a portion about the size of your hand at each meal, which works out to roughly 1.2 to 1.6 grams of protein per kilogram of body weight a day.
Research shows that faster weight loss can increase the risk of muscle loss while we’re also losing body fat. Resistance training and eating enough protein helps to prevent this.
Second Nature recommends aiming for around 0.5 kg (1 lb) a week and staying on the lowest Foundayo dose for as long as it’s effective.
A lower dose can remain appropriate when it continues to reduce hunger and food noise and is better tolerated; you can work with your prescriber to decide when to increase your dose.1
Second Nature has worked with the NHS since 2017. Take our 3-minute eligibility quiz, and a clinician will review your surgery, current symptoms, and medicines.
When to get medical help
Persistent, severe abdominal pain can be a symptom of pancreatitis. The Foundayo product information says to seek immediate medical attention because suspected pancreatitis would mean you’d need to stop taking the medication.1
Ask for an urgent GP appointment or contact NHS 111 if you have:
- Severe or worsening abdominal pain that doesn’t go away
- Yellow skin or yellowing in the whites of the eyes
- A high temperature, chills, or repeated vomiting
- Signs of dehydration, including dizziness, much less urine, or being unable to keep fluids down
Persistent watery diarrhoea without these urgent symptoms still needs a GP review, particularly if it began after gallbladder surgery or continues on a stable Foundayo dose.
Frequently asked questions
Can you take Foundayo without a gallbladder?
You can take Foundayo without a gallbladder if a clinician decides it’s suitable. Not having a gallbladder isn’t a reason not to prescribe the medication in the UK, but whether you’ll be prescribed Foundayo depends on your recovery, current symptoms, previous complications, and other medicines.1
How long after gallbladder surgery can you start Foundayo?
There’s no fixed waiting period after surgery. This is decided on a case-by-case basis, and starting Foundayo may be delayed if recovery is continuing or digestive, biliary, or pancreatic symptoms remain.
Is Foundayo less effective without a gallbladder?
The Foundayo trials didn’t report absorption or weight loss separately for people without a gallbladder.1,2
Can Foundayo cause gallstones if you don’t have a gallbladder?
New gallbladder stones can’t form if you don’t have a gallbladder. Stones can remain in the bile ducts after surgery, and bile-duct problems can still cause pain, jaundice, infection, or pancreatitis.6
Can you take Foundayo after gallstone pancreatitis?
Previous pancreatitis requires an individual clinical assessment. Foundayo hasn’t been studied in people with a history of pancreatitis, and the UK licence advises caution.1
How can you tell Foundayo diarrhoea from bile acid diarrhoea?
You can’t reliably separate the symptoms without an assessment. Diarrhoea that was present before Foundayo, began after surgery, is watery or urgent, or continues on a stable dose should be discussed with a GP.
Can you take Foundayo with colestyramine?
The medicines haven’t been studied together. The colestyramine label says to take other oral medicines at least one hour before it or four to six hours after, and a pharmacist should plan the routine around every medicine being taken.5
Why might an online provider refuse Foundayo if you don’t have a gallbladder?
Providers can use prescribing criteria that are stricter than the UK prescribing recommendations. If you’ve been denied a Foundayo prescription, that’s not because you can’t get Foundayo on prescription, only that the specific provider you’ve applied to has stricter prescribing policies.
Take home message
You can take Foundayo without a gallbladder; there’s no fixed waiting period after the surgery, and whether you’ll be prescribed Foundayo is made on a case-by-case basis. Not having a gallbladder isn’t listed as a reason not to prescribe Foundayo in the UK.1
The UK licence gives no special dosing instructions for people without a gallbladder. They weren’t excluded from the main trials, but the authors didn’t report their absorption, safety, or weight-loss results separately.1,2
New gallbladder stones can’t form if you don’t have a gallbladder, but retained bile-duct stones and pancreatitis remain possible. Previous pancreatitis, current pain, jaundice, fever, or repeated vomiting all change the clinical assessment.
Persistent watery diarrhoea may be bile acid diarrhoea rather than a side effect of Foundayo. If colestyramine is prescribed, its label advises leaving at least one hour before or four to six hours after other oral medicines, with a pharmacist planning the full schedule.4,5
At Second Nature, GLP-1 medication is combined with registered dietitian and nutritionist support, using whole-food meals, the balanced plate, and movement habits that can reduce the risk of weight regain if medication is stopped.
Our research in JMIR Formative Research found that active subscribers on Second Nature’s semaglutide-supported programme lost an average of 19.1% of their body weight at 12 months, and 77.7% achieved at least 10% weight loss.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.
