Effective dose (pharmacology) 有效剂量
（重定向自Effective dose 50）
An effective dose (ED) in pharmacology is the dose or amount of drug that produces a therapeutic response or desired effect in some fraction of the subjects taking it.
It has been stated that any substance can be toxic at a high enough dose. This concept was exemplified in 2007 when a California woman died of water intoxication in a contest sanctioned by a radio station. The line between efficacy and toxicity is dependent upon the particular patient, although the dose administered by a physician should fall into the predetermined therapeutic window of the drug.