Palo Santo (Bursera graveolens) essential oil is steam-distilled from the heartwood of a wild South American tree and is characterised by a high limonene content (~60%), with alpha-terpineol, menthofuran, and carvone as secondary constituents. Phytochemical studies confirm anti-proliferative activity against tumour cell lines attributable to the oil's complex terpenoid profile.^[1] The well-established anti-inflammatory pharmacology of limonene provides mechanistic support for the analgesic and anti-inflammatory uses documented in Andean traditional medicine.^[2]