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.

Evidence last reviewed: August 2026

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.

Scientific references

Effect of kiwifruit consumption on sleep quality in adults with sleep problems
Lin HH, Tsai PS, Fang SC — Asia Pac J Clin Nutr, 2011
Acute effects of fresh versus dried Hayward green kiwifruit on sleep quality, mood, and sleep-related urinary metabolites in healthy young men with good and poor sleep quality
Kanon AP, Giezenaar C, Roy NC — Front Nutr, 2023
Effectiveness of Melatonin-Containing Foods on Promoting Sleep: A Scoping Review
Nisar T, Fuller A, Gyawali P — Food Sci Nutr, 2026

Where to buy

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