Rick Simpson Oil (RSO) is a highly concentrated cannabis extract traditionally made using a solvent to extract cannabinoids from cannabis plant material. Because the process involves flammable solvents and legal restrictions vary by location, it carries significant safety and legal risks.Rick Simpson Oil, often called RSO, is a concentrated cannabis oil known for its thick, dark appearance and high cannabinoid content. It was popularized by Rick Simpson and is commonly associated with wellness and medical cannabis discussions.