Will I know if I'm getting a placebo in a clinical trial?

You will always be told ahead of time if a clinical trial uses a placebo at all — this is covered during informed consent and written into the consent form before you decide whether to join.

However, knowing that a trial uses a placebo is different from knowing which specific group you've been assigned to. In many placebo-controlled trials, participants aren't told during the study which group they're in, so that the comparison between groups stays unbiased.

What you can count on is transparency about the trial's design overall: whether a placebo is used, in what way, and what each group would receive. If this is a concern for you, ask the study team directly how the trial handles placebo use and whether you'd ever learn which group you were in, and when.