RG1 may refer to: Ginsenoside Rg1, a bioactive molecule a United Kingdom postcode covering Reading area RG-1 (propellant) is a Soviet/Russian rocket propellant similar to RP-1 R1–RG1 (Rodalies de Catalunya), a commuter rail line in Catalonia, Spain

RG-I may refer to: Rhamnogalacturonan I, a type of pectin