The effect of night milk versus day milk in insomnia

INTERVENTION: Night milk: 30minutes prior to bed take product orally daily for 3 weeks. Night milk is from cows milked at night and contains milk protein (600mg/100g). Dose: 250ml (25g of total milk powder). There will be a one week wash‐out period before starting arm 2 of the study. CONDITION: Insomnia PRIMARY OUTCOME: Sleep onset latency, using EEG from overnight study and estimate over one week from actigraphy. Subjective sleep quality. PROMIS Pittsburgh sleep quality index , Functional Outcomes of Sleep Questionnaire SECONDARY OUTCOME: PROMIS sleep disturbance questionnaire PROMIS sleep related impairment questionnaire Wake after sleep onset. This will be assessed using EEG during an overnight sleep study on night 21. INCLUSION CRITERIA: Sleep onset latency >30min Adult 25‐60 years PSQI score >= 7