ED50 stands for which of the following?

• A. Estimated Dose
• B. Effective Dose
• C. Efficacious Dose
• D. Endotoxin Dose

Answer: (B)

The main idea here is the median dose that produces the desired therapeutic effect. ED50 is the dose that yields the defined therapeutic response in 50% of individuals, shown on a dose–response curve. This value is a measure of potency: a drug with a lower ED50 needs a smaller dose to achieve the same effect. It is specific to the particular effect being measured and can vary with the endpoint, population, and conditions. The term is not used for “Estimated Dose,” and while “Endotoxin Dose” is a real phrase in other contexts, it’s not relevant to this concept. The standard term that ED50 represents is the Effective Dose—the dose at which 50% of subjects exhibit the desired effect.