Efficacy of Dietary Supplementation With Melatonin in Targeting Sleep Quality

The single-center, randomized, cross over, double-blind, placebo controlled intervention study will include 30 subjects who will test the efficacy of three formulations with different dosages of melatonin on sleep quality parameters.

Inclusion criteria

• subject Informed consent form (ICF) is signed
• aged 24-65 years at the time of the signature of ICF
• suboptimal sleep quality according to Pittsburgh Sleep Quality Index (PSQI-SI): PSQI higher than 5
• no clinically significant (subthreshold) insomnia according to Pittsburgh Sleep Quality Index (PSQI-SI) (Kmetec et al., 2022): PSQI up to 9
• a body mass index (BMI) up to 32 kg/m2
• stable medications for non excluded concurrent medical conditions for six weeks prior to the screening visit
• ability to ingest oral food supplement (study product)
• willing to follow all study procedures, including attending all site visits and use of actigraphy

Exclusion criteria

• diagnosed or subject to therapy due to sleep disorders
• acute infectious disease
• any kind of chronic pharmacological therapy with antihypertensives or antidepressants
• any kind of other pharmacological therapy that could interact with active ingredients used in the study
• pregnancy or planned pregnancy, lactation, menopause (with clinically relevant symptoms/therapy)
• use of beta-blockers
• chronic use of use of prostaglandin synthesis inhibitors (nonsteroidal anti-inflammatory drugs), such as acetylsalicylic acid and ibuprofen
• supplementation with melatonin or other food supplements intendent for sleep quality during last 2 weeks
• unwillingness to maintain caffeine abstinence after 4:00 PM during the study
• not having a mobile upper extremity for attaching an actigraph
• known alcohol and/or drug abuse
• unwillingness to comply with the maximum limit of 2 alcoholic drinks per day, and only up to 1 alcoholic drink after 6:00 PM during the study
• known lactose/gluten intolerances/food allergies
• known gastrointestinal disease
• less than 5 years after treatment for gastrointestinal cancer (stomach, duodenum or colon)
• have stomach or bowel resection
• night work (including as part of shift work)
• mental incapacity that precludes adequate understanding or cooperation
• participation in another investigational study