Stigmatization of skin conditions like alopecia areata (AA) and androgenetic alopecia (AGA) impairs quality of life (QoL), but research is limited. The aim of this study was to compare stigmatization and QoL in individuals with AA and AGA in German-speaking (GS) and US samples and identify stigmatization predictors. This cross-sectional online survey included AA and AGA participants from GS countries (April-August 2020) and the USA (May-August 2021). Stigmatization and QoL were assessed using the Perceived Stigmatization Questionnaire (PSQ) and Hairdex, along resilience, happiness, and social support assessment tools. Regression analyses evaluated disease severity, duration, age, gender, marital status, and social support as stigmatization predictors. All subgroups perceived stigmatization and impaired QoL. GS-AA (n = 423, 93.6% women) participants perceived more stigma but better QoL than GS-AGA (n = 102, 79.4% women). The US sample (AA: n = 199, 84.4% women
AGA: n = 47, 93.6% women) showed similar trends, though insignificant. GS participants reported higher stigma and US participants lower QoL. Stigmatization was associated with being male, younger, employed, severe disease, daily-life restrictions, and anxiety. Both samples were predominantly female, with the US sample being older and smaller, potentially reducing significance. In conclusion, sociodemographics and gender influence stigmatization and QoL. Interventions should enhance resilience and social support.