A standard Botox treatment for chronic migraines involves 31 injections split across seven muscle groups in the head, neck, and shoulders. Each injection delivers a small, fixed dose, and the entire session takes about 15 to 20 minutes. Here’s what the full treatment looks like, who qualifies, and how long it takes to work.
The 31 Injection Sites
The injections follow a specific, FDA-approved protocol. They’re distributed across seven muscle areas, with most given in symmetrical pairs on the left and right sides:
- Corrugator (between the eyebrows): 2 injections, one on each side
- Procerus (bridge of the nose/lower forehead): 1 injection at midline
- Frontalis (forehead): 4 injections, two on each side
- Temporalis (temples): 8 injections, four on each side
- Occipitalis (back of the head): 6 injections, three on each side
- Cervical paraspinals (back of the neck): 4 injections, two on each side
- Trapezius (upper shoulders): 6 injections, three on each side
Your provider may add up to 8 extra injections in areas where your pain concentrates most, bringing the total to as many as 39. But the baseline protocol is always 31.
What the Procedure Feels Like
The needle used is tiny, small enough that no numbing or anesthesia is needed beforehand. Most people describe each injection as a brief pinch or sting that fades within seconds. The areas around the temples and back of the head tend to be more sensitive than the forehead, but the discomfort is mild overall. Because each injection delivers only 0.1 mL of fluid, there’s very little pressure at the injection site. You can drive yourself home and return to normal activities the same day.
Who Qualifies for Treatment
Botox is FDA-approved specifically for chronic migraine, defined as 15 or more headache days per month, with headaches lasting 4 hours or longer per day. If you have episodic migraines (fewer than 15 days per month), Botox is not currently approved for you, even if those migraines are severe.
Insurance companies typically add their own requirements on top of the FDA criteria. Most require that you’ve tried and failed preventive medications from at least two or three different drug classes, such as beta-blockers, certain antidepressants, and anti-seizure medications. Many insurers also require that the treatment be administered by or in consultation with a neurologist or headache specialist. Expect a prior authorization process, which your doctor’s office usually handles.
How Many Rounds Before It Works
One round of 31 injections is not usually enough to judge whether Botox will help you. Treatments are given every 12 weeks, and most patients don’t see meaningful improvement until the second or third round. That means it can take six to nine months from your first session to know if the treatment is working.
This is important to understand going in, because the first round can feel discouraging. The effects of Botox build gradually as the medication repeatedly blocks the pain-signaling chemicals released by nerve endings around those muscle groups. If you’ve completed two or three full cycles with no improvement at all, you’re unlikely to respond with continued treatment, and your provider will typically recommend a different approach.
What Happens Between Sessions
The effects of each treatment session wear off over the 12-week interval. Some people notice their migraines creeping back in weeks 10 through 12 before their next appointment. This is normal and doesn’t mean the treatment has stopped working. Your provider will keep you on a consistent 12-week schedule to maintain the preventive effect.
Common side effects include neck pain or stiffness, soreness at the injection sites, and occasionally temporary weakness in nearby muscles. Some people experience mild drooping of an eyelid or eyebrow, which resolves on its own as the Botox wears off. These side effects tend to be less common after the first session, partly because your provider refines their technique based on how you respond.
Tracking Your Results
Before starting Botox, keep a headache diary for at least a month so you have a baseline to compare against. Record how many headache days you have, how long they last, and how severe they are. This makes it much easier to judge whether the treatment is actually reducing your migraine burden or if it just feels like it might be helping. A reduction of even a few headache days per month can meaningfully improve quality of life when you’re starting from 15 or more.