Remedy · fruit
Prunes for constipation: what the evidence says
The old remedy holds up: in trials, a daily handful of prunes improved constipation about as well as a fiber supplement. Research on bone density is early.
By the editors of Alimentotherapy Last reviewed 3 min read Not medical advice
Prunes
Prunus domestica (dried plums)
Best-supported use: Constipation
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The short answer
Prunes have moderate evidence for constipation: in a crossover trial 50 grams twice a day beat psyllium on bowel movements and stool consistency, and in healthy adults with low fiber intake 80 to 120 grams a day increased stool weight and frequency Attaluri 2011; Lever 2019. They work through fiber plus sorbitol, a natural sugar alcohol, and British dietetic guidelines now include them for chronic constipationStacewicz 2001; Dimidi 2025.
The evidence, use by use
Each claim graded on human studies only. How we grade
| Use | Grade | What the research found |
|---|---|---|
| Chronic constipation | Moderate | In a 40-person crossover trial, 50 g of prunes twice a day improved complete bowel movements and stool consistency more than psyllium. In a pooled review of foods, prunes and psyllium came out about level. Attaluri 2011; Vanderschoot 2024; Chey 2021 |
| Stool output in healthy adults with low fiber intake | Moderate | In a trial of 120 adults, 80 g or 120 g of prunes a day for four weeks increased stool weight and frequency compared with water alone; flatulence was more common. Lever 2019 |
| Bone density after menopause | Limited | Small trials in postmenopausal women found dried plum (50 to 100 g a day) slowed bone loss or improved some bone density measures compared with control foods. These were short trials of a few dozen women. Hooshmand 2011; Hooshmand 2016 |
How many prunes, and how to eat them
The trials used weighed amounts, so a kitchen scale is the easiest way to match them. Prune sizes vary, so weigh a portion once and count how many that is for your brand:
- 50 g twice a day in the comparison with psylliumAttaluri 2011.
- 80 g or 120 g a day with 300 mL of water in healthy adults; both raised stool frequency, and the higher dose raised stool weight the most Lever 2019.
- 100 g a day in a US comparison with kiwifruit and psyllium Chey 2021.
In the kitchen
Start with a few a day and work up over a week; the gas settles as your gut adjusts. Stewed prunes, prunes in porridge and prune puree all count. Drink water with them.
Prunes are an easy way to add fiber, and logging a few days of meals in Cronometer shows how much a daily handful moves your total.
Why they work: fiber and sorbitol
Dried prunes contain about 6.1 g of fiber per 100 g and a large amount of sorbitol, 14.7 g per 100 g, a sugar alcohol that draws water into the bowel Stacewicz 2001. Prune juice is filtered and has essentially no fiber, but it still contains sorbitol (about 6.1 g per 100 g), which is why the juice also has a laxative effect Stacewicz 2001.
The same review notes prunes are rich in potassium, about 745 mg per 100 g Stacewicz 2001. That matters if your doctor has told you to limit potassium.
Prunes, kiwifruit or psyllium?
A US trial that compared all three found each one increased complete bowel movements, with kiwifruit causing the fewest side effects and the least dissatisfaction Chey 2021. If prunes give you too much gas, try kiwifruit; if you want a measured dose, try psyllium. The regularity guide puts them side by side.
Before you try it: safety and interactions
Who should avoid it or ask first
- You have been told to limit potassium (for example with kidney disease, or some blood pressure medicines): prunes are high in it.
- You react to sorbitol or follow a low-FODMAP diet for IBS: sorbitol is one of the polyols that diet limits.
- You have constipation with severe pain, vomiting, blood in the stool or a sudden change in habit: see a clinician.
Possible side effects
- Gas and flatulence, more common with prunes than control in trials.
- Loose stools or cramping at large amounts, because of the sorbitol.
Pregnancy and breastfeeding
Prunes are an ordinary food and a common first step for constipation in pregnancy. Mention persistent constipation to your midwife or doctor. Lever 2019; Stacewicz 2001
Medicine interactions
Check another food or medicine in the interactions list.
Common questions
How many prunes should I eat for constipation?
Trials used 80 to 120 grams of prunes a day, or 50 grams twice a day; weigh a portion once to see how many prunes that is. Start with a few a day and build up, because gas is the most common side effect.
Does prune juice work as well as whole prunes?
Prune juice still contains sorbitol, about 6.1 grams per 100 grams, and that has a laxative effect, but filtering removes nearly all the fiber. Most trials used whole prunes, so whole or stewed prunes are the better-studied choice.
Are prunes better than fiber supplements?
In a 40-person crossover trial, 50 grams of prunes twice a day improved bowel movements and stool consistency more than psyllium. A 2024 review of food trials found prunes and psyllium about level. Either is a reasonable first step for mild constipation.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
- PubMedAttaluri A, et al. Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation. Aliment Pharmacol Ther. 2011. PMID 21323688.
- PubMedLever E, et al. The effect of prunes on stool output, gut transit time and gastrointestinal microbiota: a randomised controlled trial. Clin Nutr. 2019. PMID 29398337.
- PubMedChey SW, et al. Exploratory comparative effectiveness trial of green kiwifruit, psyllium, or prunes in US patients with chronic constipation. Am J Gastroenterol. 2021. PMID 34074830.
- PubMedvan der Schoot A, et al. Systematic review and meta-analysis: foods, drinks and diets and their effect on chronic constipation in adults. Aliment Pharmacol Ther. 2024. PMID 37905980.
- GuidelineDimidi E, et al. British Dietetic Association guidelines for the dietary management of chronic constipation in adults. J Hum Nutr Diet. 2025. PMID 41081513.
- PubMedStacewicz-Sapuntzakis M, et al. Chemical composition and potential health effects of prunes: a functional food? Crit Rev Food Sci Nutr. 2001. PMID 11401245.
- PubMedHooshmand S, et al. Comparative effects of dried plum and dried apple on bone in postmenopausal women. Br J Nutr. 2011. PMID 21736808.
- PubMedHooshmand S, et al. The effect of two doses of dried plum on bone density and bone biomarkers in osteopenic postmenopausal women: a randomized, controlled trial. Osteoporos Int. 2016. PMID 26902092.
Keep reading
- GoalFood for regularity: fiber, fluids, kiwifruit and prunesMost adults eat well under the fiber they need. Raising it slowly, with fluid, is the first step; kiwifruit, prunes and psyllium all have trial support.
- RemedyKiwifruitTwo green kiwifruit a day is one of the best-tested food approaches to constipation, and the gentlest on the gut. The sleep research is small and uncontrolled.
- RemedyPsylliumThe seed husk sold as a bulk fiber. It has the best evidence of any fiber supplement for chronic constipation and a solid record on LDL cholesterol.
- GoalFood and digestive comfort: bloating, gas and sensitive gutsFor a sensitive gut, enteric-coated peppermint oil and a short, dietitian-guided low FODMAP trial have the strongest evidence. Most bloating comes from what and how fast we eat.