Tart cherry
Prunus cerasus

Tart cherry is the sour cherry (Prunus cerasus), a different species from the sweet table cherry (Prunus avium). Almost all the research has been done with a single variety, Montmorency, the most widely grown according to a 2021 review.

It is sold as a concentrate to dilute, as juice or in capsules of freeze-dried fruit. What is studied in it are its polyphenols, especially the anthocyanins, the pigments that give it its deep red color. The fruit also contains small amounts of melatonin, the same molecule that is sold in tablets for sleep.

The main anthocyanin in tart cherry is cyanidin-3-glucosylrutinoside, followed by cyanidin-3-rutinoside, cyanidin sophoroside and peonidin-3-glucoside, according to a 2009 analysis of ten products funded by the cherry industry. Peonidin is disputed: the 1997 analysis does not find it, and the difference could be due to the method. Altogether, at least 24 anthocyanins, 12 phenolic acids, 17 flavanols and 18 flavones have been described, with an average of 352 mg of total polyphenols per 100 g of fresh fruit, according to the 2021 review that cites that figure.

The European list of applications for health claims includes at least four for tart cherry, two of them worded as “antioxidant support” and “joint support”, and another for the cherry stalk, referring to the urinary tract. Applying for a claim is not obtaining it, and we have not been able to verify the outcome of these applications.

Tart cherry’s sporting reputation began with studies that did not use it alone: the first ones, one of them in marathon runners who recovered their strength sooner, gave a blend with apple juice, so they could not separate the effect of the cherry.

Then came eight trials with placebo and without declared blends. The three that found something in favor (in strength, sprinting or time in a test) predate 2020 and have between 8 and 27 participants. The three most recent, from 2024 and 2026 and in capsules, saw no differences in either recovery or performance, although in one of them part of the cherry group received placebo because of a supply error. The signal exists, but it is weak, and the most recent evidence does not confirm it.

The two meta-analyses that have pooled these trials do not say the same thing. The 2026 one finds that maximal strength recovers sooner with tart cherry, but rates that conclusion as very low certainty at every time point measured, and sees no effect on muscle soreness. The 2021 one does find a small effect on muscle soreness. The 2026 one includes trials with apple juice blends and, according to its accepted manuscript, the 2021 one does too; the latter was written by authors of several of the trials it pools.

On performance, eight trained cyclists completed a 15 km time trial 4.6% faster after a week of capsules. It is one of the few trials with no funding from outside the university, although the capsules were donated by the company that supplied them. But eight people are very few to generalize from.

The 2026 meta-analysis pooled 19 trials and 385 participants, published between 2006 and 2022, and admitted non-randomized studies and comparators without placebo. Its effect on maximal isometric strength grows over time after exercise, from 0.63 right after to 2.14 at 72 hours (standardized effect sizes), with heterogeneity between trials of between 69.30% and 92.67%. It also pools a lower C-reactive protein up to 48 hours. Its sensitivity analysis shows how fragile the result is: the immediate improvement in strength stops being significant when a single trial is removed, and that of C-reactive protein depends on a trial whose participants match another’s in number and age, perhaps the same cohort counted twice. Its authors do not declare any funding or conflicts, and none of them is an author of any of the trials it pools.

The 2021 one pooled 14 studies and found effects in favor on strength (−0.78), power (−0.53) and muscle soreness (−0.44, with an interval of −0.87 to −0.02); in its convention, the negative sign favors the cherry. Its independence cannot be determined: its funding is not reported and its authors co-authored several of the included trials. A third one, from 2020, pooled ten endurance trials with an effect of 0.36 (interval of 0.07 to 0.64), but its list of studies has not been accessible, so it is not known which products it includes.

The most recent trial without a card, from 2026, assigned 50 active people to a daily 500 mg capsule of powder, with 5.8 mg of phenols per dose, or to rice flour, for the ten days around 15 sprints of 30 meters. There were no differences in any variable. But the manufacturer supplied replacement capsules with a different coding and part of the cherry group received placebo, without the article saying how many were affected; the same text states that no one switched groups. It declared an intention-to-treat analysis and analyzed only the 40 who finished. It was funded by a company where one of the co-authors worked at the time of publication.

On performance, the time trial of the eight cyclists was accompanied by a higher lactate after the preceding steady-pace segment and by a slightly higher tissue oxygenation index at rest. On whether daily intake interferes with adaptation to training, the closest thing is a two-week trial in 16 older men, in which muscle protein synthesis did not change versus placebo. It is context, not the answer.

Something similar happens with sleep. One trial described more than an hour of extra sleep, but in eight people and with figures that do not add up with its own analysis. Two others found no more sleep time, and one of them is the only health trial whose independence from the industry could be verified.

The most recent trial, from 2024 and paid for entirely by the cherry industry, gave capsules for two weeks to 34 adults with overweight and sleep problems, and found no difference at all from placebo, either in sleep or in inflammation. The favorable results are older: besides the eight-person trial (Losso card), a 2012 one with concentrate saw melatonin in the urine rise and described more sleep time, without the size of that improvement being settled.

Nor is it clear why it would work, if it works. In the trial that measured melatonin in the blood, it did not change versus placebo (Chung card).

The 2012 sleep trial, which the dossier keeps as provisional because it has not been possible to settle how many participants were analyzed, gave 20 volunteers 30 mL of concentrate twice a day for one week, versus a soft drink with less than 5% fruit, and told them that two fruit concentrates were being compared. Melatonin excreted in the urine rose versus placebo, but the time of its peak did not change: the internal clock did not shift. The manufacturer donated the concentrate, and the full funding has not been accessible.

In gout, the idea is that it lowers uric acid. A 2026 meta-analysis of four trials found a decrease that its authors describe as modest, that varies a lot between trials and that rests mainly on just one of them. The authors present tart cherry as a complement to lifestyle changes and not as a substitute for treatment, and warn that people taking allopurinol or febuxostat should not reduce or stop them on account of adding it. The only trial designed to measure gout attacks in the long term that we discuss here has no results that we have located.

The gout meta-analysis brings together four trials that are very different from one another: two are open-label, that is, the participants knew what they were taking, and one of them also uses a formula that adds citrate, a compound that, according to the authors themselves, may help eliminate uric acid. Of the eight comparisons it pools, only one shows a clear effect; in the other seven, the interval crosses zero. The result of the whole depends mainly on a single trial.

A 2020 trial in 50 people with gout, with public funding, compared four doses of concentrate and a placebo for 28 days, and found no differences either in uric acid or in attacks. It is not conclusive either: it could not be blinded, and its placebo contained a few drops of cherry extract.

The 2026 meta-analysis pools eight comparisons from four trials and gives a standardized difference of −0.22 (interval of −0.43 to −0.01), with heterogeneity of 88%. The result cannot be taken as solid: it depends mainly on a single comparison, with a difference of −3.63, which the article itself attributes in a table to the citrate trial and in its main figure to a 2019 trial with juice alone. It mixes placebo and usual-diet comparators, and counts as double-blind that 2019 trial, in adults with overweight, whose text does not declare it. Its authors do not declare any conflicts, it was funded by a public research program in China and it declares a PROSPERO registration, although its accepted version said that the review was not registered in advance.

That 2019 trial, funded by the cherry industry, reports a 19.2% drop in uric acid that is not reproduced with its own means, which give 15.2%; the difference could be due to the article averaging each participant’s changes, something that cannot be checked with what has been published.

The trial that will measure gout attacks is a protocol published in 2020: twelve months, double-blind, 120 people with gout and the frequency of attacks as the primary outcome. Two of its authors were receiving, at the time of publication, a grant from the cherry industry.

In people with non-metastatic hormone receptor-positive breast cancer who had been on an aromatase inhibitor for at least four weeks, a double-blind trial gave 1 ounce of concentrate in 8 ounces of water a day for six weeks, or a placebo syrup of undescribed composition. Of 60 patients enrolled, 48 entered the analysis: two dropped out because of diarrhea and ten did not follow the regimen, without the abstract saying in which group. Joint pain fell by 34.7% with cherry and by 1.4% with placebo, a statistically significant difference. The dossier keeps it as provisional: only the abstract has been read, which gives both 48 randomized and 60 enrolled, and it was funded by the cherry industry. It says nothing about cancer treatment or about adherence to the drug; any use is to be discussed with the oncology team.

In knee osteoarthritis, the only double-blind trial located used a blend of tart cherry and apple and did not differ from placebo. It was funded by the maker of the blend, and a co-author was, at the time of publication, a consultant to and shareholder in the company.

On blood pressure and cholesterol, the trial in people over 65 (34 people, twelve weeks, 480 mL a day of diluted concentrate) is the only main trial with a signal, and it is mixed. Systolic pressure fell 4.1 mmHg with cherry and rose 5.4 with placebo, but the cherry group started 8 mmHg higher and, at the end and adjusted, the difference was −1.54 mmHg, not significant. LDL cholesterol ended 20.6 mg/dL lower; triglycerides, 6.66 mg/dL higher, as did glucose (section 11). It was funded by the cherry industry. Three other trials, of two weeks, thirty days and three months, found no effect on the markers they measured or on inflammation.

On attention and mental tiredness there is a striking result: a three-month trial in middle-aged adults found, versus placebo, more sustained attention, more feeling of alertness and less mental fatigue. It is the only one on this page in which it was checked whether participants guessed what they were taking. It was funded by the industry, and those were not its primary outcomes.

The other trial with memory tests, in people aged 65 to 80, announced improvements in several of them in its abstract. In its own tables, none of them survives the comparison that matters: how each group changed versus the other over the course of the study. It is a good example of why it pays to read beyond the abstract.

In that trial in older adults, the abstract highlights fewer errors on a visual memory test, more satisfaction with one’s own memory and improvements on three other tests, with p values between 0.01 and 0.03. In the table, the group-by-time interactions for those same tests give between 0.06 and 0.32. And the test of repeating series of digits came out worse with cherry.

What has been studied points to three kinds of reader: people who exercise or play sports and want to recover faster, people who sleep poorly and are looking for something to help, and people who have high uric acid or gout. For the first two, the evidence is weak. For the third, the decision rests with the doctor who manages their treatment.

There is no established regimen. The trials used concentrate diluted in water, usually twice a day, juice or powder capsules: in sport, a few days before and after exercise; in sleep and health, from 48 hours up to three months. And since the content varies so much between products (section 06), the amount in one trial cannot be carried over to another product.

The concentrate is not light: 30 mL provide 25.5 g of carbohydrates and 102 kcal. For people with diabetes or who watch their blood glucose, it is something to assess with the doctor.

The regimens cited on this page are those of the trials, not a recommendation from Suplepedia.

Thirty milliliters of concentrate and a 500 mg capsule do not provide the same thing, and in several trials it is not even known how much they provided (section 06). That is why the rows of this table are not equivalent to one another. The trials’ regimens are reproduced here; they are not guidance for use.

Table · Regimens of the main trials

What each regimen provides varies more than the regimen itself. In the sport trials, what is declared ranges from 5.8 mg of phenols a day in one capsule to 611.9 mg of polyphenols in the high dose of an extract, without it being stated whether this last figure is per dose or per day. One concentrate measured by its own trial provided 7.7 mg of anthocyanins per dose; some capsules, 256.8 mg a day, with no declared method. In the two trials with extract, the article does not clarify whether the declared amount is per dose or per day, and so their daily dose cannot be calculated. With two daily doses of 30 mL of concentrate, carbohydrates add up to about 51 g a day (calculated on 25.5 g per dose).

Very little of the anthocyanins is absorbed, less than 5% of the dose in the study that measured it, and they disappear from the blood within a few hours.

Melatonin is also scarce. The highest figure located in a concentrate, 85.2 µg a day, comes from a single analysis and does not reach a third of the 0.3 mg (300 µg) that our melatonin page considers the physiological dose.

Intact anthocyanins peak in the blood between one and four hours after being taken and disappear between eight and twelve. Before them, around the first or second hour, smaller phenolic compounds appear, such as protocatechuic and vanillic acids, traces of which remain at eight hours. All of this comes from single-dose studies.

The analysis that gave the 85.2 µg figure was commissioned by the authors of a 2012 sleep trial, and it does not match what has been measured in the fresh fruit.

These are three small studies. With 45 or 90 whole frozen tart cherries, in 12 people, anthocyanins appeared in the plasma with a peak between 2 and 4 hours and in the urine between 6 and 8, and with 90 cherries the antioxidant capacity of the blood was still raised at 12 hours. In 12 men who took 30 or 60 mL of concentrate, protocatechuic and vanillic acids peaked at one or two hours. And in 10 men with gout, with 60 or 120 mL, the main anthocyanin reached maximum concentrations of 8.3 and 19.0 ng/mL depending on the dose, with a bioavailability below 5% according to its authors.

The concentrate’s melatonin figure comes from a chromatography analysis commissioned from an outside laboratory: 1.42 µg per milliliter, about 42.6 µg per 30 mL. In the fresh fruit, a 2001 analysis measured 13.46 ng per gram in Montmorency. The two known citations of a third analysis, of several products, contradict each other on which variety has more and on whether the concentrate contains it.

No. Variety, processing and batch change a great deal what is inside, and laboratories measure it with methods that give different figures. That is why two trials with “30 mL of concentrate” are not necessarily giving the same dose, and several have published contents that cannot be correct.

Table · Total polyphenols by format, compared with raw frozen fruit (Jawad 2025)

And then there is how it is measured. Some methods assess the sample as a whole, and a 2021 review describes them as not very specific; others quantify each compound separately. That same review found that, of 43 studies, only 20 had analyzed the batch they gave their participants.

None of the sources for this page names a quality seal specific to tart cherry. The only control of the content that appears in them is the analysis some trials make of their own batch (section 06).

Why the older trials came out better than the recent ones: it may be the format, the type of participant or that favorable results were published sooner. How much it matters that the taste of tart cherry gives away the placebo. And whether taking it daily changes what is gained from training, something we have not found measured.

Nor is it known why it would help with sleep, if it does. Melatonin is scarce; another hypothesis, with laboratory data and data from only eight people, points to the tryptophan pathway; a third, to inflammation. None is proven.

Several pieces of this evidence have problems that are not visible in the abstracts. In the 2026 sprint trial, the supply error pushes toward finding no differences, and its size is not declared. In the half-marathon trial with capsules, race time, which could be an effect of the cherry itself, is then used to adjust other markers, and the p values in the abstract do not match those in the table. The two main sport meta-analyses pool products that are not comparable (section 06), and at least the 2026 one includes blends with apple juice.

The explanation for the time pattern remains open. If an expectation effect mattered, capsule trials, which are easier to blind, should find less effect than juice trials, and among the recent ones that is what happens; but there are exceptions in both directions: two capsule trials came out in favor and one with concentrate found no differences.

In several trials there were dropouts because of digestive discomfort or diarrhea. In those reviewed, no serious effects attributed to tart cherry were described, although none was large enough to detect rare effects.

It is advisable to talk it over with the doctor first in several situations. With diabetes: in a trial in people over 65, glucose at the end was higher with cherry than with placebo. With gout under treatment, because tart cherry does not replace the medication. With breast cancer treated with aromatase inhibitors, where there is a small trial on the joint pain those drugs cause: any use is to be discussed with the oncology team. With anticoagulants, and during pregnancy or breastfeeding, because we have not located studies, and that does not allow risks to be ruled out.

This section describes; it does not advise. For anyone who is on a treatment, or who is pregnant or breastfeeding, it is advisable to consult their doctor before taking any supplement.

In the trial in people over 65, glucose ended 7.94 mg/dL higher with cherry than with placebo and body mass index was slightly higher, although the two groups consumed the same calories. In healthy adults, thirty days altered neither glucose nor insulin. Neither of the two results can be carried over to people with diabetes.

In two trials in people with gout, half or all of the participants were taking allopurinol or febuxostat, and in what has been read of them neither describes interactions, although neither was designed to look for them. With a blend of tart cherry and apple, a skin reaction compatible with allergy was described.

In the three-month trial in middle-aged adults, fat mass rose in both groups, and its authors attribute this to the calories in the drinks, which were the same. The published cases of interaction with warfarin that come up when searching this topic correspond to cranberry, another species, and say nothing about tart cherry. An absorption study excluded people on anticoagulants by design, which is not interaction data either.

Table · Adverse effects described in the trials (no trial was large enough to detect rare effects)