Qingquan Wang, Nianping Feng, Yongtai Zhang
Cinnamomum cassia (L.) J. Presl. (CC) is an important medicinal and edible plant with significant therapeutic potential and economic value. This review summarizes its major chemical constituents, including volatile oils, polysaccharides, flavonoids, phenolics, phenylpropanoids, and terpenoids, together with their pharmacological activities, such as antioxidant, anti-inflammatory, antimicrobial, hypoglycemic, neuroprotective, and cardiovascular protective effects. To improve quality evaluation and standardization, potential quality markers (Q-markers) are systematically identified based on phylogeny, measurability, traceability, pharmacological efficacy, and preparation characteristics. Unlike previous reviews, this work comprehensively integrates the nutritional profile, Q-marker characterization, pharmacodynamic prediction, botanical features, toxicological safety, clinical applications, and advanced drug delivery systems of CCs. This review provides a comprehensive theoretical basis for the quality control, rational utilization, and clinical translation of CC.