BACKGROUND: Tazarotene has been extensively studied in clinical trials and is widely used to treat acne vulgaris (acne), with data suggesting that is one of the most potent topical retinoids. Irritation from the cream, foam, and gel formulations has limited its use in clinical practice. OBJECTIVE: To assess the efficacy, safety, and tolerability of a unique tazarotene 0.045% lotion formulation based on polymeric emulsion technology in subjects with moderate or severe acne. Methods: A total of 1614 subjects, 9 years and older were randomized to receive tazarotene 0.045% lotion or vehicle in two identical double-blind, randomized, vehicle-controlled 12-week studies evaluating safety and efficacy (inflammatory [papules and pustules] and noninflammatory [comedonal] lesion counts and using Evaluator Global Severity Scores [EGSS]). Treatment success was defined as at least a 2-grade improvement in EGSS and ‘clear’/’almost clear’ and efficacy assessed through reduction in lesion counts. In addition, patients completed a validated Acne-Specific Quality of Life (Acne-QoL) questionnaire. Safety, adverse events (AEs), and cutaneous tolerability were assessed throughout. RESULTS: Tazarotene 0.045% lotion demonstrated statistically significant superiority to vehicle in reducing inflammatory and noninflammatory lesion counts at week 12. Mean percent reductions in inflammatory and noninflammatory lesions were 55.5% and 51.4% (Study 1, both P<0.001 versus vehicle [45.7% and 41.5%, respectively]) and 59.5% and 60.0% (Study 2, both P<0.001 versus vehicle [49.0% and 41.6%, respectively]), with tazarotene 0.045% lotion at week 12. Treatment success was achieved by 25.5% (Study 1) and 29.6% (Study 2) of subjects treated with tazarotene 0.045% lotion (both P<0.001 versus vehicle [13.0% and 17.3%, respectively]). Improvements in QoL domain scores were consistently greater with tazarotene. Tazarotene 0.045% lotion was well-tolerated. The most common treatment-related AEs were application site pain (5.3%), dryness (3.6%), and exfoliation (2.1%). CONCLUSION: Tazarotene 0.045% lotion provides statistically significant greater efficacy than vehicle in terms of lesion reduction and treatment success, with a highly favorable safety and tolerability profile in moderate-to-severe acne patients. JJ Drugs Dermatol. 2020;19(1):70-77. doi:10.36849/JDD.2020.3977