This will be a widely inclusive, three-center, open-label pilot trial enrolling 100 people living with ALS. Duke (25 participants) and Temple (25 participants) will be traditional sites that consent, screen and follow participants in person, Everything ALS (50 participants) will be a decentralized site providing virtual consenting, screening and follow up. The total time commitment will be 9 months. All participants who pass screening will provide demographics, disease characteristics, co-morbidities, and concomitant medications. They will have a baseline ALSFRS-R score obtained, a baseline slope of Listener Effort Prediction Model (LEPM)-predicted Listener Effort (LE) progression, and Motor Movement Exam (MME) score. For those who enroll at Duke or Temple, blood will be drawn for neurofilament light chain (NfL) and IGFBP7 levels. For patients at Duke or Temple who consent to lumbar puncture, CSF will be drawn for NfL and IGFBP7 levels as well. Each month after baseline, participants will be contacted by phone by each site's study coordinator to review adverse events, new co-morbidities, and concomitant medications, and to generate a new clinician-administered ALSFRS-R score. For Duke and Temple participants, at month 1, 3 and 6 they will be asked to return for in person blood draws for NfL and IGFBP7 levels. Those who sign the additional consent for lumbar punctures will have CSF drawn as well and this will be checked for NfL and IGFBP7 levels at month 3, too. LSFRS-R is routinely measured as part of clinical care. All of the described blood tests and investigational treatments are being performed exclusively for research purposes. HMB will be given at a dose of 3g daily.