How Much Olive Oil Should You Take for Constipation?

About two tablespoons per day is the dose with the most clinical support. That amount, taken plain on an empty stomach, was used in the largest randomized trial directly testing olive oil for constipation, and it produced measurable improvements in stool consistency and symptom scores within two weeks. Smaller doses have also shown benefit in specific populations, and the type of olive oil you choose turns out to matter more than you might expect.

What the Clinical Trials Actually Used

The most direct evidence comes from a double-blind randomized trial that enrolled 140 adults diagnosed with constipation. Each participant consumed two tablespoons of olive oil daily, taken plain and not mixed into food, for four weeks. Constipation symptom scores dropped significantly in both groups, but the group receiving extra virgin olive oil saw far greater improvement than the group receiving refined olive oil. By the end of four weeks, the extra virgin group’s average symptom score had fallen from roughly 11.3 to 3.5, while the refined group went from about 11.4 to 7.7.¹ That is a dramatic difference for two products most people treat as interchangeable.

A separate, smaller trial looked at constipated hemodialysis patients and started them on just 4 milliliters of olive oil per day, which is less than a teaspoon. Even at that low dose, constipation scores improved significantly over the study period, dropping from about 10.3 to 3.2 on average. The olive oil group did as well as the mineral oil group, which is the traditional medical laxative oil.² This suggests even modest amounts can help, though the study population was small and medically complex, so the dose may not translate directly to otherwise healthy adults.

Putting these together, the practical range is somewhere between one teaspoon and two tablespoons daily. If you are otherwise healthy and trying olive oil for occasional constipation, two tablespoons on an empty stomach in the morning is the best-supported starting point. If you are sensitive to fats or want to ease into it, starting with a single tablespoon and increasing after a few days is a reasonable approach that no study contradicts.

Extra Virgin Outperforms Refined

One of the more useful takeaways from the research is that not all olive oil works equally well. In the large trial described above, the extra virgin group’s stool consistency scores were significantly higher than the refined group’s by the second week, and the gap widened through week four.³ Higher stool consistency scores on the Bristol Stool Form Scale mean softer, easier-to-pass stools, which is exactly what a constipated person wants.

The likely reason is that extra virgin olive oil retains a much higher concentration of polyphenols and other minor compounds that are stripped out during the refining process. These compounds have anti-inflammatory effects in the gut and may directly stimulate intestinal motility. Refined olive oil still provides the fat-based lubrication effect, but it lacks those extra bioactive components. If you are going to try olive oil specifically for constipation, the evidence says to spend the extra money on a genuine extra virgin product. Light, “pure,” or “classic” olive oils are all refined to varying degrees and appear to deliver a weaker effect.

How Olive Oil Eases Constipation

Olive oil works through a few different mechanisms, and understanding them helps explain why the timing of your dose matters. First, the fat itself acts as a lubricant. When you take a tablespoon or two on an empty stomach, a portion of it coats the intestinal lining before being fully digested, making it physically easier for stool to move through. This is the same basic principle behind mineral oil laxatives, which are essentially non-digestible lubricants.

Second, olive oil is a strong trigger for cholecystokinin, a hormone that stimulates bile release and intestinal contractions. Compared to oils rich in polyunsaturated fats, olive oil is a particularly potent releaser of this hormone.⁴ That bile release does two things: it helps emulsify fats for digestion, and it has a mild laxative effect on the colon. If you have ever noticed that a fatty meal sends you to the bathroom, cholecystokinin is part of the reason.

Third, the monounsaturated fat in olive oil (primarily oleic acid) appears to soften stool by increasing the water content of intestinal contents. This is partly why the effect builds over days rather than hitting instantly. And for extra virgin olive oil specifically, the polyphenols add an anti-inflammatory dimension that may calm an irritated gut lining and improve overall motility.

When to Expect Results

If you are hoping for overnight relief, olive oil is probably not your best bet. The clinical trial data show that meaningful improvement in stool consistency started appearing in the second week of daily use, with the biggest gains by week four.³ This makes olive oil more of a gentle daily habit than an acute rescue remedy. Some people report feeling a mild urge to have a bowel movement within an hour or two of taking olive oil on an empty stomach, but this anecdotal response varies widely and the sustained benefit clearly builds over time.

For acute constipation where you need relief today, traditional osmotic laxatives or stimulant laxatives work faster. Olive oil occupies a different niche: it is something you add to your daily routine to keep things moving regularly, especially if you are prone to chronic or recurring constipation. Think of it less like a medicine you take when you are already backed up and more like a maintenance strategy.

How to Take It

The trial that showed the strongest results had participants take two tablespoons of olive oil plain, not cooked into food or mixed with anything else. That is about 30 milliliters, or roughly one large swallow. Most people find it easiest first thing in the morning before eating. The taste is strong if you are not used to drinking oil neat, but extra virgin olive oil has a peppery, slightly fruity flavor that many people grow to tolerate quickly.

A few practical tips that come up often:

Chase it: Follow the oil with a glass of warm water or a squeeze of lemon juice. The warmth may help stimulate peristalsis, and the lemon makes the oily aftertaste disappear.
Empty stomach matters: Taking it with or after a meal means the oil gets digested along with everything else, reducing the lubricating and cholecystokinin effects you want.
Start low if needed: One tablespoon for the first few days is fine. Some people experience mild nausea from a full two-tablespoon dose on an empty stomach at first.
Consistency over quantity: A daily tablespoon taken every morning will likely do more for chronic constipation than an occasional double dose taken only when symptoms are bad.

Mixing olive oil into a smoothie or drizzling it on a salad is a fine way to get the general health benefits of olive oil, but it dilutes and delays the concentrated laxative effect. For constipation specifically, plain and on an empty stomach is the way the research was conducted and the way the effect was measured.

Side Effects and How Much Is Too Much

Two tablespoons of olive oil adds about 240 calories to your day. If you are watching your weight, that is worth knowing, though in context it is roughly the same as a modest snack. The caloric load is the most common practical concern, and for most people it is manageable.

For digestive side effects, your body is remarkably efficient at processing olive oil. In a study that pushed healthy adults to extremely high fat intakes, including olive oil and corn oil, participants absorbed more than 98 percent of the fat even at doses up to 639 grams per day over 20 days.⁵ That is an absurd amount, over 20 times the constipation dose, and the body still absorbed nearly all of it. Abdominal discomfort and diarrhea did eventually appear, but the threshold varied enormously between individuals. One subject tolerated over 500 grams daily without symptoms. The takeaway is that two tablespoons is extremely unlikely to cause diarrhea, cramping, or fat malabsorption in a healthy person. If it does give you loose stools, you have probably found your personal threshold and can simply dial back to one tablespoon.

There is a positive correlation between the amount of fat consumed and the amount excreted, so in theory, very large doses could lead to greasy stools.⁵ But at the two-tablespoon level, this is not a realistic concern for most people.

Olive Oil for Children

Constipation in young children is extremely common, and parents understandably look for gentle remedies. The research here takes two different forms: oral and topical. For topical use, a pilot trial tested an abdominal ointment containing 85 percent olive oil in children aged one to four with functional constipation. The ointment was applied to the belly twice daily for four days. No adverse effects were reported, and the researchers described it as safe, well-tolerated, and effective.⁶ This is a gentler approach than oral dosing and avoids the challenge of getting a toddler to swallow oil.

For more severe cases, olive oil enemas have been studied in children with chronic constipation that had not responded to standard treatments. These used a dose of 1 to 2 milliliters per kilogram of body weight, administered either alone or followed several hours later by a glycerin enema.⁷ This is a clinical intervention, not something to try at home without guidance from a pediatrician. But it illustrates how seriously some clinicians take olive oil as a tool for managing difficult constipation in children.

For a child old enough to take oil by mouth, pediatric doses are not well established by trials. Many practitioners suggest starting with half a teaspoon for a small child and working up cautiously, but this is based more on clinical experience than on controlled data. The abdominal ointment approach is the only one with randomized trial support for very young children.

How Olive Oil Compares to Standard Laxatives

The hemodialysis trial found that olive oil performed as well as mineral oil, which has been used as a laxative for over a century.² That finding matters because mineral oil works but carries downsides: it can interfere with the absorption of fat-soluble vitamins, it occasionally causes lipoid pneumonia if aspirated, and it has a taste and texture most people find unpleasant. Olive oil avoids all three issues. It is a food your body knows how to digest, it provides its own nutritional value, and it is palatable enough that people can sustain the habit.

Compared to osmotic laxatives like polyethylene glycol or lactulose, olive oil works differently. Those agents pull water into the intestine to soften stool, and they work within a day or two. Olive oil’s effect is slower and more gradual, but it also does not carry the risk of electrolyte imbalance that comes with overusing osmotic laxatives. For people who need daily help with constipation and want to avoid pharmaceutical laxatives, olive oil is a reasonable option, though the evidence base is thinner than what exists for something like polyethylene glycol, which has been studied in dozens of large trials.

Stimulant laxatives such as bisacodyl or senna are faster still, often producing a bowel movement within six to twelve hours. They work by directly triggering contractions in the colon. Olive oil does not compete on speed. Where it holds an advantage is in safety for long-term daily use. Stimulant laxatives can cause dependence and tolerance with chronic use, while olive oil carries no such concern.

Interactions with Medications

Any significant amount of fat taken with medications can affect how those drugs are absorbed. Olive oil is no exception. Some medications are lipophilic, meaning they dissolve in fat and are absorbed more readily when taken with a fatty meal or an oil. This can increase the amount of drug that enters your bloodstream, sometimes significantly. Cyclosporine, an immunosuppressant, has been studied specifically in olive oil vehicles. Research in animal models showed that when cyclosporine was dissolved in olive oil, a portion of it was absorbed through the lymphatic system rather than the usual intestinal route, accounting for about 2 percent of total absorbed drug.⁸

For most common medications, two tablespoons of olive oil taken on an empty stomach hours before your pills is unlikely to cause clinically meaningful interactions. The risk is higher if you take the oil at the same time as a fat-soluble medication. Blood thinners like warfarin deserve particular caution because olive oil has a mild antiplatelet effect on its own, and very high doses could theoretically add to the blood-thinning effect. If you are on warfarin or another anticoagulant, it is worth mentioning your olive oil habit to your prescriber. For most other people, the interaction risk at a two-tablespoon daily dose is low.

When Olive Oil Is Not Enough

Olive oil is a gentle intervention, and gentleness has limits. If your constipation is caused by a medication like an opioid, by a condition like hypothyroidism, or by a structural problem like pelvic floor dysfunction, olive oil alone is not going to solve it. These causes require specific treatments. Opioid-induced constipation, for example, often needs a peripherally acting mu-opioid receptor antagonist, not dietary fat. Pelvic floor dysfunction responds to biofeedback therapy, not laxatives of any kind.

Red flags that suggest you should see a doctor rather than reaching for olive oil include constipation that comes on suddenly in someone over 50, blood in the stool, unintended weight loss, or constipation alternating with diarrhea. These patterns can signal conditions ranging from colorectal cancer to inflammatory bowel disease, and no amount of olive oil will address the underlying cause.

For garden-variety chronic constipation in an otherwise healthy person, olive oil is worth trying alongside the basics: adequate fiber intake, enough water, regular physical activity, and not ignoring the urge to go. It works best as one component of a broader strategy rather than a standalone fix. The research is encouraging but still limited in volume, and the largest trial to date enrolled only 140 people. More evidence would be welcome, but what exists points consistently in the same direction: a couple of tablespoons of good extra virgin olive oil each morning is a low-risk habit that genuinely helps keep things moving.