Rick Simpson Oil (RSO) refers to a highly concentrated, thick cannabis oil used for topical application or oral ingestion rather than smoking or vaping. RSO was popularized in the early 2000s by Canadian engineer Rick Simpson, who developed a simple method using ethanol to extract cannabis into an oil for potential use in treating skin cancer lesions. Typically, RSO oil is produced by soaking raw cannabis plant material in pure ethanol to strip away and maximize extraction of the entire spectrum of available therapeutic compounds including THC, CBD, CBN, CBC, and hundreds of minor cannabinoids, terpenes, and other constituents into a dark green, viscous oil. Dispensaries often sell convenient RSO oral applicators pre-loaded with a measured dose in a syringe for easy dosing. While RSO remains scientifically unproven as an effective cancer cure, substantial anecdotal evidence and limited studies do suggest RSO provides symptom relief for pain, inflammation, anxiety, nausea, tremors, and more when ingested or applied topically.