Comparison of MMFS Dosages in Older Adults

Inclusion Criteria: 1. Male or female subjects, aged 60 to 85 inclusive at the time of screening with informed consent. 2. Subjects with body weight within 50 to 125 kg and height within 152.4 to 198.12 cm, able to comply with study requirements; have received high school diploma, GED, or equivalent. 3. Subjects must have regular access to an internet-connected computer, iPad, tablet computer, and/or smart phone to complete online assessments. 4. Subjects with difficulty in maintaining sleep by the following criteria: * Insomnia Severity Index (ISI) score ≥ 10 and ≤ 21 * 2 (moderate) or greater on question 2 OR question 3 of ISI 5. Subjects with at least "moderate" neuropsychiatric symptoms, as determined by a score of 6 or higher on the Mild Behavioral Impairment - Checklist (MBI-C) informant-report scale; * Subjective report of worsened neuropsychiatric symptoms (e.g., MBI-C items such as motivation, depression, anxiety, impulse control, delusions) since age 50, with recent decline 6. Score ≤ 7 and ≥ 4 on the D-KEFS Trail Making Test Condition 4 - letter-number switching test of executive function at screening, controlled for motor speed (condition 5) * Subjective report of worsened memory since age 50, with recent decline 7. Score of ≤ 7 and ≥ 4 on WMS-IV Logical Memory II (Delayed) 8. Subjects must be fluent in English 9. Subject must be willing to submit to blood draw(s). 10. Subjects must be able to understand the study, agree to the requirements and restrictions, be able to attend all scheduled visits, and be willing to give voluntary consent to participate in the study. Exclusion Criteria: 1. Subject with insomnia due to bladder problems, or other confounding medical condition such as chronic pain syndromes, chronic migraine, cardiac disease, nocturia (\> 3 times/night), asthma, gastroesophageal reflux disease (GERD), or hot flashes, determined by investigators. 2. Subject diagnosed with severe sleep apnea that is not treated/well-managed (e.g., by regular use of Continuous Positive Airway Pressure, CPAP, or Bilevel Positive Airway Pressure, BIPAP, device) 3. Subject's residence is an institutional facility such as a nursing home. 4. Females of child-bearing potential as defined as status post onset of menarche and not meeting any of the following conditions: menopausal for at least 2 years, status after bilateral tubal ligation for at least 1 year, status after bilateral oophorectomy, or status after hysterectomy. 5. History or diagnosis of any of the following sleep conditions: * Narcolepsy * Cataplexy (familial or idiopathic) * Circadian Rhythm Sleep Disorder * Primary Hypersomnia 6. Subjects with history or presence of any clinically significant cardiovascular (myocardial infarction; coronary angioplasty or bypass graft(s); valvular disease or repair; unstable angina pectoris; transient ischemic attack (TIA); cerebrovascular accidents (CVA); congestive heart failure or coronary artery disease (CAD), clinically important carotid or vertebrobasilar stenosis or plaque, pulmonary, respiratory, hepatic, renal (including poor kidney function, eGFR \<55 mL/min), hematological (sickle cell anemia or thalassemia, sideroblastic anemia or anemia of any etiology), gastrointestinal, endocrine (diabetes type I or II), immunologic, dermatologic, neurological, psychiatric disease or disorder within 6 months, or any uncontrolled medical illness which in the opinion of the Investigator would jeopardize the safety of the subject. Nonetheless, subjects with controlled co-morbid conditions (including diabetes, hypertension, heart disease, etc.) are permitted if considered stable within three months of the study start. All concomitant medications, supplements, or other substances must be at stable doses for at least 3 months prior to screening and must be kept as stable as medically possible during the trial. 7. Any of the following based on clinician interview : 1. Clinically significant psychiatric illness in past 6 months requiring hospitalization 2. Other psychiatric condition that, in the investigator's opinion, would interfere with the subject's ability to participate in the study 8. Suicidal ideation with intent, with or without a plan or method in the past 1 month or suicidal behavior in the past 6 months of Screening 9. History of alcoholism or drug dependency/abuse within the last 5 years of Screening, according to interview 10. Recent history (within the 6 months prior to Screening) of regular consumption (3 or more days per week) of either: 1. 2 or more (women) or 3 or more (men) alcoholic beverages per day or alcohol consumption within 3 hours prior to bedtime 2. More than 600 mg caffeine a day (e.g., 4 standard 8-ounce cups of brewed coffee, or typically consumes caffeine after 4pm \[16:00\]) 11. Known hypersensitivity to magnesium or to any of the formulation components (not including the common laxative effects of magnesium supplements) 12. Currently participating or has participated in a study with an investigational compound or device within 30 days of signing informed consent, or intent to participate in another clinical trial at any time during the conduct of this trial 13. Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the subject due to participation in the study.