Melatonin is a hormone naturally found in our body that increases in our blood at night and controls how we sleep. Melatonin can also be taken as a pill and numerous clinical trials have documented improved sleep quality following melatonin supplementation before bed. However, it is not known whether such supplements actually increase blood melatonin above normal levels, particularly at night.

The aims of this study are to investigate whether a novel melatonin supplement (Ritual Sleep BioSeriesTM Melatonin) can increase blood melatonin in human participants at night, and to determine if taking the supplement before bed for two-weeks can improve sleep quality.

Inclusion Criteria:

• Healthy
• Aged 18-40
• Sometimes have trouble sleeping (Pittsburgh sleep quality index score >5)

Exclusion Criteria:

• Routinely taking melatonin supplements or other drugs known to affect sleep
• A diagnosed sleep disorder
• Major psychiatric illness
• Current physical injury
• Known or suspected hypersensitivity to melatonin
• Presence of major sleep disruptors at home (e.g. new born baby)
• Night shift/rotational-shift work
• Receiving non-pharmacological treatment for sleep disorder (e.g. cognitive behavioral therapy)
• Substance use disorder
• Recent (<1 month) increase in daily caffeinated drink consumption
• Consuming >14 standard alcoholic drinks per week
• Pregnant or lactating

Coded, known only to manufacturer / collaborator