THC: 67.717% CBD: 0.821% RSO Darts. The graduated lines are easy to see and will help make dosing easier for you! Rick Simpson Oil or RSO is named after a Canadian medical marijuana activist known for sharing a simple method for extracting oils from cannabis. He was motivated to share his technique after using cannabis oil to cure his own cancer. Since then, many have used cannabis oil in combination with lifestyle and diet changes to put their stage 4 cancer into remission.