Pivotal studies of approved botulinum toxin type A (BoNTA) formulations for treatment of glabellar lines have mostly included treatment-naive participants, and the impact of prior BoNTA treatment on efficacy and safety is not well documented. OBJECTIVE To evaluate whether prior BoNTA treatment affects efficacy, duration of response, and tolerability for treatment of glabellar lines. METHODS Adults with moderate or severe glabellar lines treated with DaxibotulinumtoxinA for Injection (DAXI) or placebo from the randomized, double-blind SAKURA 1/2 trials and the open-label SAKURA 3 safety study were analyzed by prior BoNTA treatment status. Efficacy was evaluated using investigator and participant assessments. RESULTS In this analysis, 609 participants (52.2% BoNTA-experienced) from the SAKURA 1/2 trials and 2,380 (38.0% BoNTA-experienced) from the SAKURA 3 study were evaluated. Proportion of participants with none or mild glabellar lines and duration of response were similar between the BoNTA-naive and BoNTA-experienced cohorts in both the DAXI and placebo groups. The incidence of adverse events was also comparable regardless of prior BoNTA treatment status. CONCLUSION Efficacy and tolerability were similar with DAXI and placebo regardless of prior BoNTA treatment. Assuming an appropriate washout is observed, future BoNTA trials should enroll both treatment-experienced and treatment-naive participants to reflect clinical practice.