Castoreum is a distinctive fragrance note that can be derived from natural sources or created synthetically. Natural versions often come from specific plants, flowers, or materials, while synthetic versions can replicate or enhance natural scents.

Castoreum has unique olfactory characteristics that contribute to the overall fragrance composition, with its own intensity, longevity, and how it interacts with other notes.

This note appears most commonly as a base note, suggesting it has deep, foundational qualities.