This exploratory trial investigates the effect of a chicken extract supplement on mental energy and its potential underlying mechanisms of action among healthy adults using a randomized, double-blind, placebo-controlled clinical trial design. Mental energy is a multi-dimensional construct comprising transient feelings about fatigue, vigor and motivation and cognitive performance in terms of sustained attention and reaction time.

A sub-study investigates the immediate biochemical changes after taking chicken extract.

Inclusion Criteria:

• Male or female at 35-64 years of age
• Assessed by investigator to be in good health
• Normal cognition based on investigator's clinical judgement per the routine practice
• Modified PSQI score > 5
• Agree to participate in the study and provide written informed consent
• Agree to abstain from herbal extracts or dietary supplements throughout the study period

Exclusion Criteria:

• BMI < 18.5 or ≥ 27 kg/m2
• Concurrent pharmacological treatments
• Current systemic diseases or current/history of neurological or cerebrovascular diseases
• Active peptic ulcer, or a history of peptic ulcer within the last 2 years
• Medications or interventions in the last 4 weeks, which in the investigators' judgement could potentially affect the outcome measures
• Regular significant quantities of dietary supplements or herbal extracts (> 2 times a week) in the last 4 weeks
• Regular excessive caffeine consumption, heavy alcohol consumption or heavy habitual smokers
• Any drastic changes in lifestyle (including diet, smoking, sleep, exercise, and mental and physical activities) in the last 4 weeks
• Not able to maintain the same lifestyle throughout the study period
• Inadequate visual and auditory acuity to allow neuropsychological testing per investigator's judgment
• Inability to undergo fMRI scan
• Any consumption of chicken extract supplement, or carnosine or anserine supplement, in the preceding 4 weeks
• History of allergy to caseinate, milk, or chicken meat
• Women who are pregnant or lactating or intending to do so
• Current enrolment in another interventional study
• Subjects who show unstable sleep habits during the previous month
• Excessive blood donation or blood drawn prior to baseline