Olive Oil for Gallstones: What the Research Shows About the Flush
Search for olive oil for gallstones and you will quickly meet the "liver and gallbladder flush": a large dose of olive oil, usually with fruit juice, taken after a day or two of fasting or special eating, followed by the passing of green, pebble-like "stones". The research tells a different story. When the "stones" from a flush were sent for laboratory analysis, they turned out to be largely soap-like fatty material made from the oil itself, not gallstones. A large dose of fat can also make a gallbladder that holds stones contract hard, which is exactly how a stone gets pushed into a duct. Olive oil as an everyday food is a separate question, and there the evidence is calmer and more interesting. This article sets out what the studies actually show, and where the line between food and flush sits.
For our own oil, see our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) — a food for the kitchen, not a flush.
The Short Answer
- There is no good evidence that an olive oil "flush" dissolves or removes gallstones. Mayo Clinic's gallstone guidance says there is "no evidence that it's an effective treatment for gallstones".
- The green "stones" people pass after a flush are not what they seem: a 2005 letter in The Lancet by Sies and Brooker reported that flush "stones" analysed in the laboratory were made largely of fatty acids — essentially soap formed from the oil — rather than gallstone material.
- A large dose of oil is not harmless if you have gallstones. Fat makes the gallbladder contract, and the NHS notes that a stone blocking a bile duct can cause severe pain, and sometimes inflammation of the gallbladder or pancreas, or jaundice.
- As an everyday food, the picture is different: in a 14-year US cohort of 45,756 men, those eating the most monounsaturated fat had a modestly lower risk of symptomatic gallstone disease (relative risk 0.83). That is an association, not proof, and not a treatment.
- If you know or suspect you have gallstones, the right first step is your GP. Severe tummy pain, a high temperature or yellowing skin or eyes need urgent help — call 999 or go to A&E in the UK, or your local emergency number elsewhere.
- Sidr & Stone sells extra virgin olive oil as a food. Please never use our oil, or anyone's, for a gallbladder flush.
What the Olive Oil Gallbladder Flush Claims
Does olive oil break down gallstones? No reliable study shows that it does. The gallbladder flush — also sold as a "liver flush" or "gallbladder cleanse" — claims that a large dose of olive oil, often mixed with citrus juice, flushes stones out of the gallbladder. Mayo Clinic notes that although olive oil can act as a laxative, there is no evidence it treats gallstones.
The idea is old. A paper titled "Treatment of Gall Stones by Large Doses of Olive Oil" appeared in the British Medical Journal as early as 1895, and the modern versions circulate as recipes with day-by-day timetables. We are deliberately not repeating those timetables or amounts here. The reason is in the next two sections: the evidence that a flush removes stones is missing, and the reasons to think it can cause harm in someone who has stones are well grounded.
Gallstones themselves are common. The NHS notes that they often cause no symptoms at all, that they can sit in the gallbladder or in the bile ducts that connect it to the liver and pancreas, and that many are found only by chance on a scan for something else.
Those Green "Stones": What Laboratory Analysis Found
The flush's persuasive power comes from what people see afterwards: dozens of soft, green or brown pebbles. It looks like proof. The most direct test of that proof is to analyse the pebbles, and that is what two doctors did.
In a 2005 letter to The Lancet, titled "Could these be gallstones?", Sies and Brooker described "stones" passed by a patient after an olive oil flush. Laboratory analysis found they were made largely of fatty acids rather than the cholesterol and bile pigment that genuine gallstones are made of. The explanation is saponification: in the gut, a large amount of oil meeting digestive juices can form soft, soap-like lumps — "stones" that were never in the gallbladder at all.
That finding matters because it removes the flush's main piece of evidence. Passing green lumps after drinking a large amount of oil tells you the oil went through you. It does not tell you a single gallstone moved.
What about studies that claim success? The most recent we found is a 2026 single-patient case report in Advances in Mind-Body Medicine (Uma Devi and colleagues): a 59-year-old man with gallstones, already on conventional medication, underwent three flush sessions over six months alongside an apple-based diet, and his ultrasound stone size fell. The authors themselves note that a single case limits how far the result can be generalised. One patient, with several things changing at once and no comparison group, cannot tell you whether the flush did anything.
Why a Large Dose of Oil Can Be Risky With Gallstones
The gallbladder's job is to store bile and squeeze it out when you eat fat. That squeeze is normal and healthy. In someone with gallstones, though, it is also the moment a stone can be pushed into the narrow ducts that drain the gallbladder — and a deliberately large dose of oil asks for a strong squeeze.
The NHS describes what happens when a gallstone blocks a bile duct: tummy pain that can be severe and constant, last from 30 minutes to several hours, sit in the middle of the tummy or under the right ribs, and come with sickness or vomiting. This is biliary colic. The NHS also lists the rarer but serious complications of a blockage: inflammation of the gallbladder (cholecystitis), inflammation of the pancreas (pancreatitis), and jaundice. A hospital FAQ from Gleneagles in Singapore makes the same point directly about flushes: trying to flush out gallstones can cause a blockage.
When to get help. NHS advice is to ask for an urgent GP appointment or contact NHS 111 if tummy pain lasts longer than 30 minutes, and to call 999 or go to A&E if you have sudden severe tummy pain, pain spreading to your back with vomiting, a very high temperature or shivering, or yellowing of the skin or the whites of the eyes. Outside the UK, use your local urgent care or emergency number. Our article on olive oil side effects covers who else should be careful with large amounts.
What the Research Shows About Olive Oil in Everyday Eating
Take away the flush and a more useful question remains: does the kind of fat you eat day to day relate to gallstone risk? Here the human evidence is modest but real, and it points in a sensible direction.
| Study | Design and size | What it found | Honest limits |
|---|---|---|---|
| Tsai et al., Annals of Internal Medicine, 2004 | Prospective cohort, 45,756 US male health professionals, 14 years, 2,323 new cases | Highest vs lowest fifth of monounsaturated fat intake: relative risk 0.83 (95% CI 0.70 to 1.00) for symptomatic gallstone disease | Observational; men only; monounsaturated fat from all foods, not olive oil specifically |
| Baggio et al., American Journal of Clinical Nutrition, 1988 | Controlled diet study, 11 young volunteers on a metabolic ward | Olive-oil-enriched diet cut LDL cholesterol by 12.2% vs a low-fat diet; bile cholesterol saturation and gallbladder volumes were unchanged | Very small; healthy volunteers, not people with gallstones |
| Sies and Brooker, The Lancet, 2005 | Letter: laboratory analysis of flush "stones" | The "stones" were largely fatty acids — soap-like material, not gallstones | A single analysis, not a trial; but it addresses the flush's central claim directly |
The Health Professionals Follow-up Study analysis by Tsai, Leitzmann, Willett and Giovannucci is the strongest piece here. Men in the top fifth for cis-unsaturated fat intake had a relative risk of 0.82 for gallstone disease compared with the bottom fifth, and the authors concluded that a high intake of these fats, within an energy-balanced diet, was associated with lower risk. Association is not causation, and this was not an olive oil study — but olive oil is one of the richest everyday sources of monounsaturated fat.
The 1988 Baggio study is a useful counterweight. Swapping to an olive-oil-enriched diet improved blood lipids, but it did not change the measures of bile that relate to cholesterol stone formation. In other words, olive oil looks like a sensible everyday fat; it does not look like a gallstone treatment. That fits the NHS list of risk factors, which includes a diet high in fat and low in fibre — the overall pattern matters more than any single ingredient. Our pieces on olive oil and the liver and olive oil and gut health take the same food-not-medicine approach.
Three Fair Objections
"But I have seen the photos of the stones." So have we, and they are convincing until you know what they are made of. The one laboratory analysis published in a major journal found soap-like fatty material, not gallstones. Something real comes out; it simply is not what the flush promises.
"A case report says a flush shrank someone's gallstones." It does, and we have described it above. It is one patient, already on conventional treatment, with a diet change at the same time and no comparison group — the authors themselves call for proper trials. That is a reason to study the question, not a reason to try it at home.
"Olive oil is healthy, so what is the harm?" Olive oil in normal culinary amounts and a large single dose taken to provoke the gallbladder are different things. The first is a food with a good research record; the second deliberately triggers the contraction that can move a stone into a duct. If you have no gallstones, the flush has nothing to remove; if you do, it carries real risk.
If You Have Gallstones: Sensible Next Steps
None of this means doing nothing. It means doing the things that are known to help, and acting on the urgent signs above rather than waiting them out.
- See your GP if you have symptoms or have been told you have gallstones; an ultrasound scan is the usual test.
- Do not self-treat with a flush or cleanse, and do not stop any prescribed treatment.
- If you are waiting for treatment, follow the dietary advice you are given — the NHS notes you may be advised to eat a low-fat diet.
- For everyday eating, use olive oil in normal culinary amounts as a replacement for less helpful fats, not as an extra on top. Our guide to how much olive oil per day sets out what the studies used.
- If you want to drink olive oil neat for other reasons, read our piece on drinking olive oil first, and check with your GP if you have gallstones.
When you are choosing an oil for the kitchen, our guide to choosing a quality olive oil covers grade, origin, harvest dates and storage.
Why Sidr & Stone
We sell olive oil for cooking, dressing and eating — and we would rather lose a sale than see our oil used for a flush. Everything below describes how Sidr & Stone's oil is grown and made; none of it is a health claim.
- Sidr & Stone's extra virgin olive oil comes from a single estate — our own family-owned farm near Marrakech, Morocco — and we control every step from tree to bottle, with no blending across origins.
- The Sidr & Stone grove is rain-fed, with no irrigation; the trees take what the season gives.
- Sidr & Stone's olives are organically grown, with no synthetic fertilisers, pesticides or herbicides (not yet certified; certification is in progress).
- Each Sidr & Stone release is a small, limited single-harvest batch; once it is gone, it is gone until the next harvest.
- Sidr & Stone's oil is cold-pressed within hours of harvest to protect flavour, aroma and polyphenols.
- It is unfiltered extra virgin, minimally processed, and may show a little natural sediment — normal in an unfiltered oil.
- It is 100% natural — a single ingredient, olive oil, with no additives.
- It is bottled in 500ml dark glass with a gold label to protect it from light.
- Sidr & Stone gives 10% of profits to charity, with fulfilment in the UK, EU, and US.
We will not tell you our oil is good for gallstones — that is exactly the claim this article warns against. What we will say is that it is single-estate Moroccan, rain-fed, organically grown and cold-pressed within hours of harvest, made to be enjoyed a spoonful at a time in good food.
Frequently Asked Questions
Is olive oil good for gallstones?
Olive oil is not a treatment for gallstones. As an everyday fat, monounsaturated-rich diets were linked with modestly lower gallstone risk in one large cohort of men, but a large dose of oil taken as a flush is not supported by evidence and can trigger pain in people with stones.
Does a gallbladder flush with olive oil work?
There is no good evidence that it removes gallstones. The green lumps passed afterwards were shown in a 2005 Lancet analysis to be largely fatty, soap-like material formed from the oil, not gallstones.
How do I know if I have gallstones?
Often you will not — gallstones frequently cause no symptoms. Pain under the right ribs or in the middle of the tummy is a reason to see your GP, who may arrange an ultrasound scan.
Can a gallbladder flush be dangerous?
It can be in people with gallstones. Fat makes the gallbladder contract, which can push a stone into a duct and cause biliary colic; the NHS lists cholecystitis, pancreatitis and jaundice among the complications of a blockage.
Is Sidr & Stone olive oil suitable for a liver or gallbladder flush?
No. We sell extra virgin olive oil as a food, and we ask customers never to use it — or any oil — for a flush or cleanse. If you have gallstones, speak to your GP before making any big change to how much oil you eat.
Can I still use olive oil if I have gallstones?
Many people with gallstones use olive oil in ordinary cooking, but follow the advice of your GP or dietitian, particularly if you have been advised to eat a low-fat diet while waiting for treatment.
Where can I buy Sidr & Stone olive oil?
Directly from our product page, as a limited single-harvest batch, with fulfilment in the UK, EU, and US.
Is olive oil a medicine?
No. Olive oil is a food, not a medicine. It has a long traditional history — including being honoured in the Prophetic Sunnah — and a substantial body of modern research, particularly around polyphenols, cardiovascular health, and the Mediterranean diet pattern. It can be a worthwhile part of a healthy routine, but it does not cure diseases and is not a substitute for medical care. Be cautious of any olive oil marketed with specific disease-cure claims.
Final Thoughts
The olive oil gallstone flush survives on one striking image: a bowl of green "stones". Once you know that a laboratory analysis found those stones to be soap-like material made from the oil, the case for the flush falls away, and what is left is a real risk for anyone who has gallstones — a hard gallbladder contraction that can push a stone where it should not go.
Olive oil as food deserves a fairer hearing. In a large cohort, diets richer in monounsaturated fat were associated with a modestly lower risk of gallstone disease, and swapping to olive oil improved blood lipids in a small controlled study. That is a reason to cook with good oil in sensible amounts, within a varied, fibre-rich diet — and to take gallstone symptoms to a doctor rather than to a recipe.
Our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) is single-estate, rain-fed and cold-pressed within hours of harvest, available as a limited single-harvest batch with fulfilment in the UK, EU, and US.
Our extra virgin olive oil is grown organically on our own single-estate farm on the plains outside Marrakech: we control every step from tree to bottle, and no synthetic pesticides, herbicides or fertilisers are used. It is not yet certified organic — certification is in progress, and we will publish it as soon as it comes through.
References
- Sies CW, Brooker J. Could these be gallstones? Lancet. 2005;365(9468):1388. doi:10.1016/S0140-6736(05)66373-8. PMID: 15836886.
- Tsai CJ, Leitzmann MF, Willett WC, Giovannucci EL. The effect of long-term intake of cis unsaturated fats on the risk for gallstone disease in men: a prospective cohort study. Ann Intern Med. 2004;141(7):514-522. doi:10.7326/0003-4819-141-7-200410050-00007. PMID: 15466768.
- Baggio G, Pagnan A, Muraca M, Martini S, Opportuno A, Bonanome A, Ambrosio GB, Ferrari S, Guarini P, Piccolo D. Olive-oil-enriched diet: effect on serum lipoprotein levels and biliary cholesterol saturation. Am J Clin Nutr. 1988;47(6):960-964. doi:10.1093/ajcn/47.6.960. PMID: 3132035.
- Uma Devi K, Saravanan V, Vijaya Bharathi E, Mooventhan A. Effect of Six Months of Gallbladder Flush on Size and Symptoms of A Patient With Cholelithiasis: A Case Report. Adv Mind Body Med. 2026;40(2):28-31. PMID: 40982748.
Disclaimer: This article describes what published research and NHS guidance say about olive oil, gallbladder flushes and gallstones at the time of writing; research findings and guidance may change, and readers should check current sources. It does not describe how to do a flush and does not recommend one. Olive oil is a food, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, including suspected gallstones, consult a qualified medical professional.