FECO- Fully extracted cannabis oil. RSO - After its namesake Rick Simpson. The big difference between FECO and RSO is the solvent used to extract the cannabinoids and other plant compounds. We use a very safe 200 proof, food grade ethanol, whereas RSO was traditionally extracted with less safe solvents. Strong and highly medicinal. Full spectrum cannabis concentrate. Intended for oral use. Please consult your healthcare provider for dosing suggestions tailored to your health condition.