Patient experience data from social media capture unsolicited patient conversations and help understand their subjective experiences of illness and treatment. Unlike electronic health records, which only capture the perspective of doctors, social media allows us to learn how patients experience their condition, its progression, treatment, unmet needs and impact on daily life. Regulatory bodies such as the FDA and EMA recognize the potential of this data for patient-centered drug development. The document suggests best practices for social media listening in the areas of study purposes and objectives, data collection and data analysis. They illustrate these procedures with a case study that reveals key symptoms and comorbidities in patients with type II diabetes and their impact on quality of life over a 24-month period. The goal is to establish a rigorous methodological foundation for patient experience data that can support clinical trials, post-marketing evidence, and regulatory processes.