The short version
- A randomised crossover trial in 20 volunteers found tart cherry juice concentrate significantly raised total urinary melatonin and increased total sleep time and sleep efficiency, without shifting circadian timing.
- In 15 older adults with insomnia, tart cherry juice significantly reduced only minutes awake after sleep onset; sleep latency, total sleep time and efficiency were not significantly better than placebo.
- A polysomnography study found an 84-minute increase in sleep time, but it had only eight completers, and three of the original eleven volunteers were excluded and referred because they had sleep apnea.
- The largest study, in 44 participants over 30 days, found no significant difference in sleep time or quality between Montmorency tart cherry and placebo.
- The authors of the 15-person trial noted their own effect was considerably smaller than that of hypnotic drugs or cognitive behavioural therapy for insomnia.
Most of the plants sold for sleep are sold on tradition. Tart cherry is unusual: it is sold on a molecule. Montmorency cherries genuinely contain melatonin, and that gives the claim a mechanism you can point at. Then you look at how many people have been studied, and the confidence drains out of the room.
Twenty volunteers, and a measurable hormone
Howatson and colleagues ran the study that started this, published in the European Journal of Nutrition. Twenty volunteers took either a tart cherry juice concentrate or placebo for seven days in a randomised, double-blind, placebo-controlled crossover, with sleep tracked by actigraphy and questionnaire and 48 hours of sequential urine collection.
Total urinary melatonin content was significantly elevated in the cherry juice condition, with no difference between baseline and placebo. Time in bed, total sleep time and sleep efficiency all increased significantly with the concentrate. The timing of the melatonin circadian rhythm did not shift; there was only a trend toward a higher peak and amplitude.
That last point is more informative than it looks. If cherry juice worked purely as a circadian timing signal, you would expect the rhythm to move. It did not. What changed was how much melatonin was in the system, and the sleep measures that went with it were duration and efficiency rather than phase.
Then the samples get smaller, not bigger
Pigeon and colleagues tested a proprietary tart cherry blend in 15 older adults with chronic insomnia, crossover, two weeks per arm. Against placebo, the only significant improvement was in minutes awake after sleep onset. Sleep latency, total sleep time and sleep efficiency showed no significant advantage over placebo. Their own summary of effect sizes: moderate, and in some cases negligible.
What makes that paper worth citing is the paragraph most supplement pages would skip. The authors put the effect in context themselves: comparable to or exceeding what has been observed in studies of valerian and in some studies of melatonin, but considerably less than the effects of evidence-based insomnia treatments — hypnotic agents and cognitive behavioural therapy. That is a research team volunteering that their own product's effect is second-tier.
Losso and colleagues went further and used polysomnography. Eleven subjects were randomised; three were excluded because they turned out to have sleep apnea and were referred on. The eight completers increased sleep time by 84 minutes on polysomnography, and the kynurenine-to-tryptophan ratio fell, suggesting the juice's procyanidin B-2 was making more tryptophan available by inhibiting an enzyme that degrades it.
Eighty-four minutes is a big number. Eight people is a small number. Both of those facts are load-bearing, and any page quoting the first without the second is misleading you. Notice too that three of eleven volunteers with "insomnia" actually had a breathing disorder — a rate that should make anyone pause before treating persistent bad sleep as a supplement problem.
The trial that found nothing
Hillman and colleagues gave 44 participants either two 240 ml bottles a day of Montmorency tart cherry juice, a placebo drink, powdered cherry capsules, or placebo capsules, for 30 days. Sleep was tracked daily. There were no significant differences in sleep time or quality between groups, though both improved over the 30 days — which is exactly what regression toward the mean looks like when you recruit people during a bad patch. Blood pressure and body composition were unaffected. The authors say plainly that their results conflict with the previous data.
This is the largest of the four studies and it is the negative one. That ordering matters. In a young literature, the pattern where small positive pilots are followed by a larger null result is common, and it usually means the early effect was smaller than it looked.
Why we are not selling you a cherry capsule
We do not stock one, and this article is part of why. The total randomised evidence here is under a hundred people across four studies pointing in three directions. Tart cherry sits in the same tier as valerian: a plausible ingredient with a coherent story and an evidence base too thin to justify a confident claim, let alone a premium.
There is also a practical problem with the capsule form specifically. The trials that found benefits used juice concentrate and 240 ml servings; the study using powdered capsules found nothing. Whatever is doing the work — melatonin content, procyanidins, or the placebo of a nightly ritual — may not survive being dried into a pill.
What we'd actually tell you
If you like cherry juice, drink it. It is a food, it is cheap relative to supplements, it carries a small real dose of melatonin, and the worst case is that you enjoyed a drink. Two things to keep in mind: concentrate carries a meaningful sugar load, and the melatonin in it is unquantified on the label, so if you are also taking a melatonin supplement you are stacking without knowing the total.
Do not buy it expecting an 84-minute result. Do the free work first — caffeine timing, alcohol, a consistent wake time — because ordinary sleep hygiene has more evidence behind it than this does. And if bad sleep has been going on for months, remember that three of eleven volunteers in the polysomnography study were sent to a sleep physician instead. That is a better outcome than another bottle.
Good questions
How much tart cherry juice should I drink for sleep?
The trials that found benefits used juice concentrate over seven days or two 240 ml servings a day for two weeks. That is the studied range. Be aware that the concentrate carries a real sugar load and the melatonin content is not quantified on the label, so if you also take a melatonin supplement you are stacking an unknown amount on top of a known one.
Do tart cherry capsules work as well as the juice?
There is no evidence that they do. The positive studies used juice or concentrate; the one study that tested powdered tart cherry capsules found no effect on sleep time or quality over 30 days. Whatever is doing the work may not survive being dried into a pill. If you are going to try this, the juice is the form with the data.
Does tart cherry juice contain enough melatonin to matter?
It measurably raises melatonin in the body, which is more than most sleep botanicals can claim. In a crossover trial, total urinary melatonin was significantly elevated after cherry juice concentrate and unchanged after placebo. What it did not do was shift the timing of the melatonin rhythm, so it behaves less like a circadian signal and more like a small top-up.
Why does LUVO not sell a tart cherry supplement?
Because the total randomised evidence is under a hundred people across four studies that point in three directions, and the largest of them found nothing. We would have to overstate that to sell it. Tart cherry is a pleasant food with a plausible mechanism and a thin evidence base, and we would rather you bought a bottle of juice from a supermarket.
Is an 84-minute increase in sleep realistic?
No, not as an expectation. That figure comes from eight people who completed a pilot study, and three other volunteers were excluded because they had sleep apnea. Small pilots produce large numbers; the larger 44-person trial found no difference at all. Treat 84 minutes as an artefact of sample size rather than as a prediction about your week.
Sources
- Howatson G, Bell PG, Tallent J, Middleton B, McHugh MP, Ellis J. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr, 2012. View study
- Pigeon WR, Carr M, Gorman C, Perlis ML. Effects of a tart cherry juice beverage on the sleep of older adults with insomnia: a pilot study. J Med Food, 2010. View study
- Losso JN, Finley JW, Karki N, et al. Pilot Study of the Tart Cherry Juice for the Treatment of Insomnia and Investigation of Mechanisms. Am J Ther, 2018. View study
- Hillman AR, Trickett O, Brodsky C, Chrismas B. Montmorency tart cherry supplementation does not impact sleep, body composition, cellular health, or blood pressure in healthy adults. Nutr Health, 2026. View study
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
