The goal of this clinical trial is to learn if AB-free kava works to improve mobility and physical function in older adults with sleep difficulties. It will also learn about the safety of AB-free kava. The main questions it aims to answer are:

• Does AB-free kava improve physical function and/or mobility?
• Does AB-free kava effect sleep, stress, or cellular signaling? Researchers will compare AB-free kava to a placebo (a look-alike substance that contains no drug) to see if AB-free kava works to improve mobility and physical functioning.

This research study is testing whether a specially prepared form of kava, a traditional plant-based supplement, can help improve mobility, sleep, and stress in older adults. Kava has been used safely for centuries in the South Pacific as a natural remedy for relaxation and better sleep, but some modern versions raised safety concerns due to rare liver problems. Researchers have developed a safer version called "AB-free kava," which removes compounds (flavokavains A and B) believed to cause liver issues. Early lab and pilot studies suggest AB-free kava may help improve sleep, reduce stress, decrease inflammation, and support physical activity. This pilot clinical trial will enroll 40 sedentary adults age 70+ who have sleep difficulties. Participants will be randomly assigned to receive either AB-free kava (225 mg/day) or a placebo daily for 8 weeks. The study is double-blind, meaning neither participants nor researchers will know which treatment each person is receiving. Participants will complete visits at the start, midpoint (week 4), and end (week 8) of the study. At each visit, researchers will assess walking ability, grip strength, and sleep quality using wearable activity trackers and validated questionnaires. Blood and hair samples will be collected to measure stress hormones and inflammation. Participants will be screened for eligibility based on age, sleep problems, mobility, and general health. Those with significant health conditions, cognitive impairments, or certain medication use will not be eligible. The study aims to test whether AB-free kava is safe, acceptable, and potentially beneficial for improving sleep and physical function in older adults. If results are promising, this could lead to future larger studies testing AB-free kava as a natural option to support healthy aging.

Inclusion Criteria:

• Age > 70 years
• 8 ≤ Insomnia severity index (ISI) ≤21
• 4m walking speed <1 m/sec and >0.44 m/sec
• Mild to moderate physical impairment (Short Physical Performance Battery score < 10)
• Sedentary lifestyle (< 150 min per week of moderate intensity physical activity) verified by CHAMPS questionnaire
• Willingness and ability to give informed consent
• Willingness to be randomized to the intervention groups
• Availability for participation through duration of study Exclusion Criteria (General)
• Failure to provide informed consent
• History or clinical manifestation of diabetes, cholelithiasis, liver or renal disease, cancer, or progressive, degenerative neurologic disease (e.g., Parkinson's Disease, multiple sclerosis, ALS)
• Abnormal laboratory markers (e.g., renal or liver abnormalities, elevated potassium levels, or hemoglobin and hematocrit below the lower limit of normal)
• Residence in a Skilled Nursing Facility (SNF); residence in an Assisted Living Facility (ALF) or independent housing is allowed
• Self-reported inability to walk one block
• Significant cognitive impairment, defined as a known diagnosis of dementia or a Mini-Mental Status Exam score < 24
• Severe rheumatologic or orthopedic diseases (e.g., awaiting joint replacement, active inflammatory disease)
• Terminal illness with life expectancy less than 12 months, as determined by a physician
• Severe cardiac disease, including NYHA Class III or IV congestive heart failure, clinically significant aortic stenosis, history of cardiac arrest, use of a cardiac defibrillator, or uncontrolled angina
• Severe pulmonary disease, pneumonitis or interstitial lung disease
• Other significant co-morbid disease (e.g. renal failure on hemodialysis) or severe psychiatric disorder (e.g. bipolar, schizophrenia)
• Current use of antidepressant medications, antipsychotic agents, monoamine oxidase inhibitors, anticholinesterase inhibitors (i.e., Aricept)
• Refuses to reduce alcohol use to 3 or fewer alcoholic drinks per week during the study
• Planning to permanently leave the area in the next year
• Blood pressure readings >180/100 at screening
• Participating in another clinical trial or has received an investigational product within 30 days prior to screening/enrollment.

Exclusion Criteria (AB-free kava-related)

• Regular use of any medications that contain acetaminophen
• Current use of any forms of kava and not willing to stop for a 2-week washout period - dietary supplements or beverages
• Current use of antidepressant medications and antipsychotic agents (including monoamine oxidase inhibitors), or anticholinesterase inhibitors (i.e., Aricept)
• Diagnosed with liver dysfunction or with previous liver diseases during the past five years
• Levels of ALT, AST, ALP or total bilirubin over 3xlimit of normal (ULN) range at prescreen

Temporary Exclusion Criteria

• Acute infection (urinary, respiratory, other) or hospitalization within 1 month
• Myocardial infarction, CABG, or valve replacement within past 6 months
• Pulmonary embolism or deep venous thrombosis within past 6 months
• Stroke, hip fracture, hip or knee replacement, or spinal surgery within past 4 months
• Receiving physical therapy for gait, balance, or other lower extremity training