The opposite of the phrase "most neutralized" can depend on the context in which it is used. However, some possible antonyms are "most charged," "most potent," "most active," and "most alive." In a chemical sense, "most neutralized" refers to the state of a substance after it has been stripped of its acidic or alkaline properties, so antonyms might include "most acidic" or "most alkaline." In a more general sense, "most neutralized" could mean something that has been made neutral or unremarkable, so antonyms might include words like "most distinctive," "most prominent," or "most outstanding." Ultimately, the appropriate antonym for "most neutralized" depends on the meaning and context of the phrase.