The effect of onabotulinumtoxinA for chronic migraine wears off over time, which is why treatment is given on a repeating cycle rather than once. Benefit often builds over the first few cycles rather than peaking immediately after the first treatment.
The effect of onabotulinumtoxinA for chronic migraine wears off over time, which is why treatment is given on a repeating cycle rather than once. Benefit often builds over the first few cycles rather than peaking immediately after the first treatment.
The medication's effect on nerve endings is temporary. As it wears off, the pain-signal dampening it produced diminishes and headache frequency tends to drift back up, which is why the treatment is scheduled at intervals rather than given once and reviewed. Your neurologist sets the interval; do not extend it on your own because you feel well, since the point is to prevent the pattern re-establishing rather than to respond to it after it has.
Many people notice more benefit from the second or third cycle than the first. That matters practically, because judging the treatment on one round is the commonest reason an effective preventive gets abandoned. Your neurologist will usually specify how many cycles constitute a fair trial before deciding. Agreeing that in advance is worth doing, because it turns a vague sense of whether it is working into a defined decision point.
By counting headache days per month and comparing against your pre-treatment baseline, not by how you feel in the days after an injection. Keep a simple calendar tally. That record is what makes the decision to continue, adjust the pattern or stop an evidence-based one rather than an impression. Injections are given in the office at either location; this practice performs no surgery and operates no infusion suite.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: American Academy of Neurology; MedlinePlus, National Library of Medicine; MedlinePlus: migraine.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.