Median effective dose
The median effective dose (ED50) refers to the dose of a drug or biologic that produces a specific beneficial therapeutic response in 50% of the population that takes that dose. A dose-response curve is used to determine the median effective does. In order to be useful, the mean effective dose of a drug or biologic should be much less the median toxic dose (TD50).
StatPearls: ED50 [Internet, 2020]
Merck Manual Professional Version: Dose-Response Relationships
Estimating the Maximum Safe Starting Dose in Initial Clinical Trials for Therapeutics in Adult Healthy Volunteers
Content and Format of the Dosage and Administration Section of Labeling for Human Prescription Drug and Biological Products