How many times can I randomize in a study?

It depends on whether your study uses cohorts.

• For cohort studies, you can randomize into cohorts only one time.
• For studies without cohorts, you can randomize one or more times in a study.

When subjects are randomized a second or higher time, you can move some or all subjects into new treatment arms. And the study can change from being blinded to open label (or open label to blinded) after randomization, or you can leave it unchanged.

You can also move subjects into different treatment arms without randomizing again. If the protocol requires subjects to swap treatment arms without a second randomization event, simply select the appropriate treatment for each week while defining the dispensation schedule.