Inclusion Criteria:  Males and females between 8 and 65 years of age (inclusive) at Screening Genetically confirmed diagnosis of PWS. Documentation of genetically confirmed diagnosis of PWS is acceptable. The same caregiver is available to complete the questionnaire throughout the duration of the study. After completion of the Tolerability period, Patients will have a mean HQ-CT score >= 13 and a decrease of HQ-CT score no more than 7 during Tolerability (run-in) period If receiving growth hormone, psychotropic therapy, metabolic treatments that could affect appetite (including metformin), and other treatment including thyroid hormone, must be on the same medication and dose for at least 4 weeks prior to consent/assent  Exclusion Criteria:  Known use of cannabis or cannabinoid containing products (including topical products) within 4 weeks prior to consent/ assent Use of prescription or over-the-counter weight loss agents within 4 weeks prior to consent/assent Implementation of new food or environmental restrictions within 4 weeks of consent/ assent Living in a group home setting 50% or more of the time Uncontrolled chronic conditions (diabetes, sleep apnea, etc.)