Tart Cherry Juice Warnings: Who Should Not Take It

Tart cherry juice is a food, and for most adults the only "warning" is the one that applies to any fruit juice: sugar. The cautions that matter are specific. A 30 mL serving of Montmorency concentrate carries about 365 mg of potassium, 18% of the adult reference intake, a consideration for anyone with chronic kidney disease or on a potassium-sparing diuretic, an ACE inhibitor or an angiotensin receptor blocker.¹ Cherries contain sorbitol, which loosens stools and which the NHS tells people with IBS to avoid.^{2, 3} Unsweetened juice is still free sugar, capped by the NHS at 150 mL a day.⁴ There is no NHS warning page about tart cherry, no published liver injury linked to it, and its melatonin is measured in nanograms.⁵ This is the safety page beside the Wellgard sleep guide and the Wellgard ashwagandha guide; what the fruit is studied for is on what is tart cherry good for.

Is there an NHS warning about tart cherry juice?

No. What the NHS does say applies by extension. Fruit juice counts as at most one of your five a day, limited to 150 mL daily and taken with meals, because the sugars freed by juicing damage teeth; even unsweetened juice is a source of free sugars.^{4, 6} Adults need about 3,500 mg of potassium a day from food; too much from supplements can cause stomach pain, nausea and diarrhoea.¹ People with kidney disease whose blood tests show high potassium are referred to a dietitian.⁷ People with IBS are advised to avoid sorbitol.³ And for gout, the condition tart cherry is most often bought for, frequent attacks or high urate need uric acid-lowering medicine taken regularly, even when symptom-free.⁸ What to drink before bed sets the juice beside the other bedtime drinks.

Who should not drink tart cherry juice, or should ask first?

Nobody is told to avoid cherries as a fruit. These groups should read the label and ask a pharmacist before taking a concentrate or capsule daily:

• Chronic kidney disease, especially stage 3 or beyond, or dialysis. Damaged kidneys clear potassium slowly and renal dietitians count every source.⁷
• Potassium-sparing diuretics (spironolactone, eplerenone, amiloride), ACE inhibitors (ramipril, lisinopril and the other -prils), angiotensin receptor blockers (losartan and the other -sartans) and prescribed potassium supplements. All raise blood potassium; a daily concentrate adds to it, so tell the prescriber.
• Diabetes. Concentrate is natural sugar in a small volume; count it like any juice and check your readings when you start.⁶
• IBS, fructose or sorbitol intolerance, or a sensitive gut. See the stomach section below.
• Pregnancy and breastfeeding. Cherries as food are fine; concentrates and capsules carry a label instruction to consult a GP first, because there is no supplement-dose data in pregnancy.
• Children. Diluted juice is a food; concentrates are adult supplements labelled keep out of reach of children.
• Allergy to cherries or other stone fruits, usually an itchy mouth, occasionally more.

Read the label of any concentrate for its potassium and natural sugars per 30 mL serving; food-supplement labels also say to consult a GP if pregnant, breastfeeding, taking medication or under medical supervision.

Is tart cherry juice bad for your kidneys?

Not for healthy kidneys, and it is not a kidney "cleanse" either: the uric acid fall in one 48-hour study of 48 healthy adults was about 8% within hours, in a study without a water control; against water a single serving made no difference.^{9, 17} Healthy kidneys excrete potassium easily and the 3,500 mg a day the NHS cites comes from food; a medium banana carries around 400 mg, so 365 mg from concentrate is a banana's worth.¹ When kidney function is reduced, that amount can push blood potassium up, and high potassium can disturb heart rhythm, which is why the caution exists.⁷ With kidney disease, ask your renal team, who know your latest potassium result. Kidney stones: no adult trial; the one trial, in children, is on cherries and gout.

Does tart cherry juice upset your stomach?

It can, and the reason is sorbitol. Cherries are among the fruits that contain this sugar alcohol, measured at 0.5 to 6 g per 100 g across the sorbitol-containing fruits in one food-composition survey; it is poorly absorbed, draws water into the bowel and ferments lower down.² At the volumes the American sleep trials used, 240 mL of juice twice a day, that is a lot of cherries, and readers describe bloating, wind and loose stools.¹⁰ People with IBS are told by the NHS to avoid sorbitol altogether.³ The fixes: a smaller amount, concentrate diluted rather than large glasses of juice, with food, and stopping if the gut objects.

How much sugar is in tart cherry juice, and does it matter?

All the sugar in unsweetened tart cherry juice is the fruit's own, and juicing frees it, which is why the NHS treats even unsweetened juice as free sugar and limits it to 150 mL a day.^{4, 6} Concentrate packs that sugar into a smaller volume: read the "of which sugars" line per serving and treat it like a glass of juice. For someone with diabetes it is counted like any carbohydrate; and it goes with a meal, not sipped through the evening.

Does tart cherry juice interact with medicines?

There is no drug-interaction study on tart cherry, so this is pharmacology and label text, in UK medicine names and without doses.

Sources for the rows: the NHS potassium guidance, the 2016 blood-pressure study, the 2012 gout study and the 2001 fruit assay.^{1, 5, 11, 12}

Is tart cherry juice safe in pregnancy, for children and every day?

In pregnancy, cherries and a glass of diluted juice are food, and the NHS list of foods to avoid has nothing against them; the question is the concentrate or capsule dose, for which there is no pregnancy data, so labels say consult your GP.¹³ For children, diluted juice is a food; concentrates are adult products kept out of reach. Every day: most trials ran one to two weeks, the longest 12; a 30 mL serving of concentrate is a fruit portion with a banana's worth of potassium and a glass of juice's sugar, an ordinary daily food for an adult with normal kidneys and no medicine in the table.^{10, 15, 18}

Frequently asked questions

Is there a tart cherry liver warning?

No. No published case report links tart cherry to liver injury, none of the trials reported a liver signal, and there is no regulator notice. Any new supplement that coincides with dark urine, pale stools, itching or yellowing eyes is stopped and a GP seen the same day, and a suspected reaction can be reported to your local authority's trading standards or environmental health team, which works with the Food Standards Agency.¹⁴

What are the side effects of tart cherry concentrate, extract or capsules?

Loose stools and bloating from sorbitol at larger amounts; the sugar load of concentrate; and the potassium consideration for the kidney and medicine groups above. Capsules carry less sugar and sorbitol. No trial reported a serious adverse event.^{9, 10, 11}

Does the melatonin in cherries make them unsafe with sleep medicines?

No. Montmorency cherries contain 13.46 nanograms of melatonin per gram, so 100 g carries about 1.3 micrograms, around a thousandth of a prescription tablet.⁵ Do sour cherries help you sleep explains why the figure is so often misquoted in milligrams.

Is tart cherry juice a laxative, and does it help constipation?

It can loosen stools, because cherries contain sorbitol, a sugar alcohol that draws water into the bowel; that is why large glasses do it and 30 mL of concentrate rarely does. No trial has tested tart cherry for constipation. The NHS constipation page lists other sorbitol fruits, fluids and fibre, and does prune juice help constipation covers the fruit with trials.¹⁶

Is sour cherry juice good for you, according to the NHS?

The NHS has not said. It counts cherry juice as fruit juice: one portion of five a day at most, 150 mL, with a meal.⁴

Sources

1. NHS. Vitamins and minerals: others (potassium). nhs.uk/conditions/vitamins-and-minerals/others.
2. Muir JG, et al. Measurement of short-chain carbohydrates in common Australian vegetables and fruits by high-performance liquid chromatography (HPLC). Journal of Agricultural and Food Chemistry, 2009. PubMed 19123815.
3. NHS. Diet, lifestyle and medicines for IBS. nhs.uk/conditions/irritable-bowel-syndrome-ibs/diet-lifestyle-and-medicines.
4. NHS. 5 A Day: what counts? nhs.uk/live-well/eat-well/5-a-day/5-a-day-what-counts.
5. Burkhardt S, et al. Detection and quantification of the antioxidant melatonin in Montmorency and Balaton tart cherries (Prunus cerasus). Journal of Agricultural and Food Chemistry, 2001. PubMed 11600041.
6. NHS. How does sugar in our diet affect our health? nhs.uk/live-well/eat-well/food-types/how-does-sugar-in-our-diet-affect-our-health.
7. NHS. Chronic kidney disease: living with. nhs.uk/conditions/kidney-disease/living-with.
8. NHS. Gout. nhs.uk/conditions/gout.
9. Hillman AR, Uhranowsky K. Acute ingestion of Montmorency tart cherry reduces serum uric acid but has no impact on high sensitivity C-reactive protein or oxidative capacity. Plant Foods for Human Nutrition, 2021. PubMed 33506357.
10. Losso JN, et al. Pilot study of the tart cherry juice for the treatment of insomnia and investigation of mechanisms. American Journal of Therapeutics, 2018. PubMed 28901958.
11. Keane KM, et al. Effects of Montmorency tart cherry (Prunus cerasus L.) consumption on vascular function in men with early hypertension. American Journal of Clinical Nutrition, 2016. Supplier-funded. PubMed 27146650.
12. Zhang Y, et al. Cherry consumption and decreased risk of recurrent gout attacks. Arthritis and Rheumatism, 2012. PubMed 23023818.
13. NHS. Foods to avoid in pregnancy. nhs.uk/pregnancy/keeping-well/foods-to-avoid.
14. Food Standards Agency. How to report a food safety or hygiene issue for members of the public. gov.uk.
15. Howatson G, et al. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. European Journal of Nutrition, 2012. PubMed 22038497.
16. NHS. Constipation. nhs.uk/conditions/constipation (page last reviewed 26 October 2023).
17. Lamb KL, Lynn A. Tart cherry juice has no acute effects on uric acid, vascular function and inflammation: a randomised crossover trial. Nutrition and Health, 2026. PubMed 41604330.
18. Wang C, et al. Arthritis Research and Therapy, 2023. Randomised trial, 12 weeks. PubMed 37679816.

General information, not medical advice: with kidney disease, diabetes or any regular medicine, ask a pharmacist before a daily cherry concentrate or capsule.