Cork By-Products as Bioactive Ingredients: From Waste Valorization to Pharmaceutical Prototypes

The pharmaceutical sector has evolved toward innovation-driven and sustainability-oriented development, driven by increasing regulatory pressure and global health challenges. In this context, cork (<i>Quercus suber</i> L.) has emerged as a promising bio-based resource due to its renewable nature, near-zero-waste processing chain, and growing evidence of biological activity. Cork by-products are rich in phenolic compounds, triterpenes, lignin derivatives, and other secondary metabolites exhibiting antioxidant, anti-inflammatory, and anti-aging properties, with relevance for pharmaceutical and dermocosmetic applications. These bioactivities are associated with the modulation of oxidative stress, inhibition of pro-inflammatory signaling pathways, and support of skin barrier function. This review provides an updated and focused overview of the chemical composition, bioactive potential, and valorization pathways of cork by-products, with particular emphasis on their translation into pharmaceutical and dermocosmetic formulations. Key challenges related to extraction standardization, bioavailability, safety, and clinical validation are critically discussed, highlighting future directions for the sustainable development of cork-derived bioactive ingredients within circular bioeconomy frameworks.