This is a drug utilization and safety study evaluating initiators of Mysimba in the EU and US using administrative health databases, patient registries, and drug registers. The EU study will report on data from national health databases (Sweden, Norway, Finland, Denmark) that have at least 750 new users of Mysimba from 2017 and beyond. The US portion of the study will report on data from the Arcadia Database. The primary objectives are to describe demographic and baseline characteristics of initiators and to evaluate patterns of Mysimba initiation and use, including use among group that are inconsistent with the labelled indication (e.g. age <18 years, no obesity/overweight indication, alternative doses), and (b) use incompatible with contradictions set out in the SmPC (e.g. uncontrolled hypertension, seizure disorders, renal failure, hepatic impairment, dependence/withdrawal of opioid, opioid agonist, alcohol/benzodiazepine withdrawal). Secondary objectives will describe the occurrence of adverse events of special interest (AESIs), and evaluate event occurrence for patient groups (any user, users compliant with SmPC, uses out of compliance). Secondary objectives will also assess duration of Mysimba use and will explore information related to titration scheme (e.g. change, alignment with SmPC), dose adjustments, reasons for treatment discontinuation, and adverse events leading to treatment discontinuation. Descriptive statistics will be performed to describe user groups and treatment duration and patterns. The incidence of AESIs will be estimated with rates and 95% confidence intervals based on person-time at risk. Reasons for treatment discontinuation will be explored using available recent (e.g. within 90 days before/after discontinuation) data prior to the end of known treatment discontinuation.