<![CDATA[Cosmos caudatus Kunth, a tropical medicinal herb traditionally used across Southeast Asia, has emerged as a promising botanical ingredient for cosmeceutical applications. This narrative review systematically synthesizes current evidence on its dermatological properties through comprehensive literature search of Scopus, PubMed, Google Scholar databases (2015-2025). Phytochemical characterization consistently identifies flavonoid glycosides, particularly quercetin derivatives (quercitrin, isoquercitrin, rutin), as major bioactive constituents responsible for multifaceted skin benefits. In vitro studies demonstrate potent antioxidant activity (IC₅₀ 17.77-163.6 μg/mL in DPPH assay), significant inhibition of collagenase, elastase, and matrix metalloproteinases underlying anti-aging effects, and superior tyrosinase inhibition (IC₅₀ 6.803 μg/mL) for skin brightening. Photoprotective capacity exhibits substantial formulation-dependent enhancement, progressing from minimal protection in raw extracts (SPF 3.26) to ultra-protection in optimized cream formulations (SPF 45.59). Advanced delivery systems including nanotechnology (particle size 160-176 nm) and microencapsulation (79.67% flavonoid retention) further enhance stability and bioavailability. Additional antimicrobial activity against Propionibacterium acnes positions C. caudatus uniquely for acne-hyperpigmentation management. Despite robust in vitro evidence, clinical validation through human trials remains a critical research priority. This review establishes C. caudatus as a scientifically validated, multifunctional botanical ingredient with substantial commercial potential in the natural cosmeceutical market.]]>
