Studying Melatonin and Recovery in Teens

Inclusion Criteria: Patients/youth: * Age 12-18 years * Participants undergoing elective major musculoskeletal surgery for eligible conditions * California state resident * Regular access to internet and smartphone * Can read and understand English or Spanish Parents/caregivers * Biological parent or legal guardian of youth * Can read and understand English or Spanish Exclusion Criteria: Patients/youth * Prescription medication for premorbid insomnia * Cognitive impairment or developmental delay * Does not agree to a 1-week washout if taking over the counter supplements or other sleep aids prior to the start of the study medication * High risk for sleep related breathing disorder * Chronic medical condition that is severe/systemic or requires regular treatment regimen * Psychiatric admission in prior 30 days * Patients that underwent major surgery in the last 3 months, or those that have not fully recovered from a prior surgery * BMI ≥ 99th percentile * Enrollment in another therapeutic study * Any serious underlying medical or psychiatric condition, that, in the opinion of the investigator, would contraindicate the patient's participation in the study