Background <p>Botulinum toxin (BTX) injection remains the mainstay for addressing dynamic glabellar lines. However, traditional morphology-based classifications may not exhaustively encompass the heterogeneous sums of glabellar muscular vectors. This study aims to propose and evaluate the efficacy of a muscle-based strategy that centers on direct assessment and neuromodulation of expression muscles contributing to glabellar lines.</p> Methods <p>A retrospective review was conducted on patients who underwent BTX injection between July 2022 and July 2025. Expression muscles that potentially contribute to glabellar lines, including depressor supercilii, corrugator supercilii, procerus, frontalis, and orbicularis oculi, were sequentially assessed during exertive frowning and accordingly neuromodulated. Esthetic outcomes were recorded through standardized photographs taken at baseline and follow-ups. Patient satisfaction was assessed using FACE-Q questionnaires and a self-designed patient-reported discomfort grading scale.</p> Results <p>A total of 823 patients were included in the study, reporting generally high satisfaction rates. No severe complications were recorded; transient ecchymosis occurred in 2.07% of the included cases. Post-treatment discomfort or unnatural expressions were reported by 12.39% of the cohort, with 79.41% resolving spontaneously within 2&#xa0;weeks.</p> Conclusions <p>This muscle-based paradigm provides an anatomically guided, conceptually intuitive framework for glabellar line treatment, with a favorable safety profile, yet its clinical advantages over conventional approaches remain to be further validated.</p> Level of Evidence IV <p>This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors <a href="http://www.springer.com/00266">www.springer.com/00266</a>.</p>