The two pivotal Mirvaso trials (2013)

Two identically designed trials, 260 people in one and 293 in the other, compared brimonidine gel with the same gel minus the active drug, once daily for four weeks. The gel beat the plain gel across the full 12 hours on days 1, 15 and 29, with a difference showing as early as 30 minutes after the very first application. Side effects were mostly mild, short-lived skin reactions. Worth knowing: the trial authors reported no rebound, no tachyphylaxis and no worsening of other rosacea signs. The rebound problem surfaced later, once large numbers of people were using it outside of studies.