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Limited evidenceSleep & relaxation

Kiwifruit Extract

Kiwifruit is one of the few whole foods with published sleep data, but the studies used fresh fruit, were small, and mostly lacked a placebo group. Extract capsules have not been tested at all.

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What the science says

  • Sleep onset and quality with whole kiwifruit Limited evidence

    The frequently cited study gave two kiwifruit an hour before bed for four weeks to 24 adults with sleep problems and reported shorter sleep onset and better sleep efficiency. It was an uncontrolled, unblinded single-arm study, so expectation effects cannot be excluded.

  • Acute effects on a single night Limited evidence

    A controlled study comparing fresh versus dried Hayward green kiwifruit in healthy young men found little consistent acute effect on objective sleep measures, with some changes in mood and sleep-related urinary metabolites. The results do not clearly replicate the original four-week findings.

  • Serotonin and melatonin content as the mechanism Limited evidence

    A scoping review of melatonin-containing foods notes that kiwifruit is among the fruits studied for sleep promotion, but concludes that the dietary amounts involved are small relative to supplemental melatonin doses. Whether the extract format retains any of the relevant compounds is untested.

Dosage & safety

Studied doseThe studied intake was two medium green kiwifruit (roughly 130–150 g) one hour before bed. No dose has been established for concentrated extracts, and label doses of 250–500 mg are not equivalent to the fruit intake used in the studies.
SafetyKiwifruit is a common food allergen, sometimes with severe reactions, and cross-reacts with latex, avocado and banana — avoid if sensitised. The actinidin enzyme can irritate the mouth. High-oxalate content is a consideration for people prone to kidney stones. Otherwise low risk at food-level intakes.

How to take it

TimingOne hour before bed - that is exactly how the studies dosed it, and it is the only tested schedule.
With food?It is food; two whole kiwifruit is the intake that was studied, eaten as a bedtime snack.
Worth knowingCapsules listing 250-500 mg of 'kiwifruit extract' are not the same as two whole fruit - if you want the studied effect, buy the fruit.

Frequently asked questions

Does eating kiwi before bed help you sleep?

The evidence is limited. One uncontrolled study of 24 adults eating two kiwifruit an hour before bed for four weeks reported faster sleep onset, but it had no placebo group and a later controlled study found little consistent effect.

Do kiwifruit extract capsules work for sleep?

Kiwifruit extract capsules have not been tested at all; the sleep studies used whole fresh kiwifruit. A 250-500 mg capsule is not equivalent to two whole fruit, so if you want the studied intake, eat the fruit.

Is kiwifruit safe for everyone?

Kiwifruit is a common food allergen, sometimes causing severe reactions, and cross-reacts with latex, avocado and banana. Its oxalate content also matters if you are prone to kidney stones.

Scientific references

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