Dextromethamphetamine is a stronger CNS stimulant than levomethamphetamine; however, both are neurotoxic, addictive and produce the same toxicity symptoms at high doses.
Dextromethamphetamine is a stronger CNS stimulant than levomethamphetamine; and, levomethamphetamine is a stronger PNS stimulant. Both are neurotoxic, addictive and produce the same toxicity symptoms at high doses.