One hundred and twenty-eight male and female active duty personnel, adult dependent and retiree patients from the Navy Medical Center at Camp Lejeune who meet the International Classification of Headache Disorders 3rd Edition (ICHD-3) criteria of ≥15 headache days per month lasting 4 hours or longer will participate in the trial. Subjects will be group-allocated randomly, 64 to onabotulinumtoxinA and 64 to incobotulinumtoxinA. Injections of either treatment will occur twice, 12 weeks apart, in the head and neck regions. The primary treatment efficacy measurement will be the mean change in headache days 12 to 24 weeks post-treatment. Participants will complete an electronic diary to report headache days, their severity, and adverse effects or unforeseen events. A baseline will be established four weeks prior to the first botulinumtoxinA (Botox or Xeomin) administration using the number of headache days and two questionnaires, Headache Impact Test-6 (HIT-6) and the Migraine Specific Quality (MSQ) Questionnaire, which assess headache impact and Health-Related Quality of Life (HRQOL), respectively. These questionnaires will also be administered at weeks 12 and 24 of the study. The baseline, 12-, and 24-week analysis will be performed using a time vs. treatment repeated measures analysis of variance for headache days. Secondary outcomes (total scores of both the HIT-6 and MSQ) will be analyzed similarly.