What is open label drug study

A study of the effects of a drug in a group of patients in which both the patient and the person evaluating the effectiveness of the therapy know exactly what drug and dose of drug is being taken. Typically a drug of interest is compared to either an existing standard (control) treatment, or no treatment if there is not an established effective therapy. Though much easier to perform than double-blind clinical trials, the reliability and applicability of the results of open label drug studies are less clear since both patients and the evaluators might have a bias towards wanting the study drug to work better than the control treatment.