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.