Aimovig is a prescription medication approved for the preventive treatment of migraine in adults. It was the first FDA-approved therapy designed to block a specific protein receptor involved in migraine attacks, and it’s used to reduce the number of migraine days per month rather than to treat attacks once they start. It comes as a self-administered injection taken once monthly.
How Aimovig Prevents Migraines
During a migraine, a signaling molecule called CGRP (calcitonin gene-related peptide) floods the brain and surrounding tissues. CGRP dilates blood vessels and triggers intense inflammation along pain pathways, which drives the throbbing head pain, nausea, and light sensitivity that define a migraine attack. People with frequent migraines tend to have elevated CGRP activity even between attacks.
Aimovig is a lab-made antibody that physically attaches to the CGRP receptor, blocking the molecule from binding and activating pain signaling. It was specifically engineered to latch onto a unique site on the receptor formed by two protein components, which makes it highly selective. It doesn’t suppress CGRP everywhere in the body or interfere with other closely related receptors. This targeted approach is a key reason Aimovig causes relatively few side effects compared to older migraine preventives like blood pressure medications or antidepressants, which affect the whole nervous system.
Who It’s Designed For
Aimovig is approved for adults 18 and older with migraine, whether episodic (fewer than 15 headache days per month) or chronic (15 or more). It has not been studied in children, and its safety in patients under 18 is unknown.
The American Headache Society now considers CGRP-targeting therapies like Aimovig a first-line option for migraine prevention. That means your doctor can prescribe it without requiring you to try and fail on older preventive medications first, though insurance coverage may still impose those requirements.
How Well It Works
In long-term data from patients with chronic migraine who started with an average of about 18 migraine days per month, Aimovig at the higher dose reduced that number by roughly 10.5 days. The lower dose reduced migraine days by about 8.5 per month. Those are averages, so some people experience near-complete relief while others see a more modest improvement.
Most clinical trials measured results over three to six months, and many patients noticed improvement within the first month or two. Doctors generally recommend giving Aimovig at least three months before deciding whether it’s working well enough to continue.
Dosage and How You Take It
Aimovig comes in two strengths: 70 mg and 140 mg. Both are injected once a month using either a prefilled autoinjector (similar to an EpiPen) or a prefilled syringe. Most people start at 70 mg, and your doctor may increase to 140 mg if you need more relief.
You inject it yourself at home into the skin of your abdomen, thigh, or upper arm. The autoinjector does most of the work: you press it against your skin, click the button, and hold it in place for about 15 seconds. The medication needs to be refrigerated but should sit at room temperature for 30 minutes before injection to reduce discomfort. Each device is single-use.
Side Effects
Aimovig has a notably mild side effect profile. In clinical trials involving over 1,200 patients on the medication, only two side effects occurred meaningfully more often than with a placebo injection.
- Injection site reactions (redness, pain, or swelling at the injection spot) occurred in 5 to 6% of patients on Aimovig compared to 3% on placebo.
- Constipation affected about 3% of patients on the higher 140 mg dose, compared to 1% on placebo. At the 70 mg dose, constipation rates were similar to placebo.
Since Aimovig reached the market, post-approval monitoring identified a less common but more serious concern: new or worsening high blood pressure. Some patients developed significant blood pressure elevations, including cases that required emergency care. This doesn’t happen to most people, but if you’re already monitoring your blood pressure or have cardiovascular risk factors, it’s worth tracking your readings after starting treatment.
How Aimovig Compares to Older Preventives
Before CGRP-targeting drugs arrived, the main options for migraine prevention were medications originally developed for other conditions: beta-blockers, certain antidepressants, and anti-seizure drugs. These can be effective, but they come with systemic side effects like fatigue, weight gain, cognitive fog, and dizziness that cause many people to stop taking them.
Aimovig’s advantage is its precision. Because it targets only the CGRP receptor rather than broadly altering brain chemistry, it avoids many of those quality-of-life trade-offs. The monthly injection schedule also simplifies adherence compared to daily pills, which is a practical benefit for people who struggle with consistent medication routines. The main disadvantage is cost. Without insurance coverage, Aimovig can run several hundred dollars per month, though manufacturer savings programs and prior authorization appeals can reduce out-of-pocket expenses significantly.