"There are a wide variety of chemical compounds that have been studied for radioprotective effects.Although there is promising research, chemical radioprotectants have not been shown to be very effective and, within one limited exception, are not the standard of care in medicine."

Can Radiation Risks to Patients Be Reduced Without Reducing Radiation Exposure? The Status of Chemical Radioprotectants
Mettler JR FA et al
AJR 2011;196:616-618