Iohexol is a contrast agent.Target: OthersIohexol is a contrast agent. The osmolality of iohexol ranges from 322 mOsm/kg-approximately 1.1 times that of blood plasma-to 844 mOsm/kg, almost three times that of blood. Despite this difference, iohexol is still considered a low-osmolality contrast agent; the osmolality of older agents, such as diatrizoate, may be more than twice as high.