Affect of Melatonin on Sleep and Cognition in Cirrhosis

The goal of this clinical trial is to learn the affect of melatonin on sleep, cognitive function, and quality of life (QoL) in patients with cirrhosis and a complication called hepatic encephalopathy (HE). The main questions this study aims to answer are: * Does taking melatonin increase REM sleep, an important part of healthy sleep that is reduced in cirrhosis? * Does taking melatonin improve cognitive function and reported QoL? This is a pilot study, where participants will: * take one month of melatonin, followed by one month of thiamine, which is another supplement but is not suspected to impact sleep significantly. * Undergo cognitive testing and take surveys * Wear a commercial wearable sleep tracker * Have a formal sleep study and salivary melatonin collection at the end of taking each supplement at our sleep center Participants will be blinded, and neither they nor the researchers will know which supplement they are taking first and which they are taking second. They will also be randomized, with half starting with melatonin and the other half starting with thiamine.