The objective of this Phase 1 study is to assess the safety and efficacy of single treatment of AGN-151586 and of OnabotulinumtoxinA in the glabellar complex of participants with moderate to severe glabellar lines (GL).

Inclusion Criteria:

• Has moderate or severe glabellar lines (GL) at maximum frown as assessed by both the investigator and participant using the Facial Wrinkle Scale (FWS).
• Must be in good health as per investigator's judgment based on medical history, physical examination, vital sign measurements, 12-lead ECG parameters, clinical laboratory evaluations, and neurological assessment.

Exclusion Criteria:

• Active infection or dermatological condition at the treatment injection sites.
• History of immunization to any botulinum neurotoxin serotype or hypersensitivity to any botulinum neurotoxin serotype or any other constituents of the study drug or its excipients, and/or other products in the same class.