: being or relating to a clinical trial in which the treatment given to each subject is not concealed from either the experimenters or the subject <an open–label multicenter study> — compare double-blind, single-blind
First Known Use of open–label
Medical Definition of open–label
: being or relating to a clinical trial in which both the researchers and the patients know who receives the drug and who receives a placebo <long-term open–label studies>—compare double-blind, single-blind
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