This study investigates the impact of Aalpha-s1 casein hydrolysate (ACH; Lactium®) on sleep quality in individuals with chronic insomnia, employing both subjective sleep profiles and objective polysomnography (PSG) recordings.

During the trial, the use of food or health products containing sedative or hypnotic ingredients or formulations is prohibited.

Inclusion Criteria:

1. age between 20 and 80 who meet the diagnostic criteria for chronic insomnia according to the International Classification of Sleep Disorders (ICSD) (Third Edition);
2. PSQI score greater than 5;
3. participants must voluntarily agree to participate in the trial after explanation by a physician and complete the informed consent form.

Exclusion Criteria:

1. currently using tranquilizers, hypnotics, or stimulant-related medications or substances (such as coffee or energy drinks);
2. patients with a history of significant head trauma;
3. individuals with alcohol abuse within the past year;
4. those with other severe medical conditions (e.g., hepatic or renal dysfunction);
5. Pregnant women or breastfeeding mothers;
6. participants unable to comply with the trial schedule;
7. individuals on a vegetarian diet;
8. those with allergies to dairy products.