Missed a Dose of Aimovig (Erenumab)? Here's What to Do
Medically reviewed by Lauren Okafor | MD, The Frank H Netter MD School of Medicine, Loyola University Medical Center on July 26th, 2026.
Published on July 23rd, 2026. Updated on July 26th, 2026.
Key takeaways
Erenumab's long half-life of about 28 days means one missed dose rarely causes an immediate migraine rebound, but the protection window is not unlimited.
Inject the missed dose as soon as you remember, unless your next scheduled dose is only a few days away. In that case, skip it and resume your normal schedule.
Double-dosing is never appropriate. It does not restore protection faster and may increase the risk of side effects.
Missing two or more consecutive monthly doses warrants a conversation with your prescriber about the best way to safely resume treatment.
Simple strategies like recurring calendar alerts, autoship enrollment, and proper pen storage can prevent most missed doses before they happen.
How Erenumab Dosing Works and Why Timing Matters
Aimovig (erenumab) is a once-monthly subcutaneous injection prescribed in either a 70 mg or 140 mg dose. It belongs to a class of medications called CGRP receptor antagonists, which work by blocking calcitonin gene-related peptide activity, a key driver of migraine attacks. Because the medication targets this pathway at the receptor level, it requires consistent monthly dosing to maintain a stable therapeutic effect in the bloodstream.
Unlike daily oral migraine preventives, a monthly injectable gives patients a longer buffer if a dose is delayed. However, that buffer has limits. Erenumab's protective effect is tied directly to how much of the medication remains active in your system, and that level declines over time without a new injection. Understanding this relationship helps explain both why one missed dose is unlikely to be a crisis and why multiple consecutive missed doses can meaningfully set back your progress.
What to Do Immediately After Missing a Dose
The standard guidance for a missed erenumab dose is straightforward. Inject the missed dose as soon as you remember, even if it is several days late. From that point, reschedule your next injection one month out from the new injection date.
The main exception is when your next scheduled dose is very close, typically within a few days. In that scenario, it is better to simply skip the missed dose and continue on your original monthly calendar. This approach keeps your schedule clean and avoids any confusion about overlapping doses.
What you should never do is inject two doses at the same time to compensate. Double-dosing does not accelerate the return of migraine protection and may increase the likelihood of side effects such as injection-site reactions or constipation. One dose, on your adjusted schedule, is the right path forward.
How Your Migraine Protection Is Affected by a Gap
One of the reassuring features of erenumab is its long half-life of approximately 28 days. This means that even after a missed injection, the medication does not vanish from your system immediately. For most patients, meaningful migraine protection can persist for several weeks beyond the missed dose window.
That said, migraine frequency may begin to creep back around 4 to 6 weeks after the last injection, and individual responses vary. Patients who are particularly sensitive to changes in their preventive regimen may notice earlier or more pronounced returns of headache activity.
For patients who miss multiple consecutive monthly doses, the recovery timeline is longer. It may take approximately 2 to 3 months of resumed consistent dosing to regain the full preventive effect. This makes early action, and communication with your prescriber, especially important when multiple doses have been skipped.
Scenario |
Recommended Action |
When to Call Your Doctor |
|---|---|---|
Missed dose, next injection is more than 1 week away |
Inject the missed dose now, reschedule next dose 1 month later |
Only if unusual side effects occur after reinjecting |
Missed dose, next injection is within a few days |
Skip the missed dose, resume on original schedule |
If migraines worsen significantly before the next dose |
Missed 2 or more consecutive monthly doses |
Contact your prescriber before restarting |
Yes, call to discuss a safe restarting strategy |
Pen may have been stored incorrectly or exposed to heat |
Do not inject. Contact your pharmacist first |
If you are unsure whether the medication is still effective |
Common Reasons Doses Are Missed and How to Prevent Them
Specialty pharmacy delays are among the most common causes of missed erenumab doses. Because Aimovig is not stocked at most standard retail pharmacies, patients rely on scheduled shipments that can occasionally be delayed or arrive damaged.
Practical strategies to reduce missed doses include setting a recurring monthly calendar alert tied to a memorable date, enrolling in autoship programs through your specialty pharmacy, and using reminder tools available through the Aimovig manufacturer support program. Staying a few days ahead of your scheduled injection date by tracking shipments proactively can also help.
Proper storage is equally important. Erenumab autoinjector pens should be kept refrigerated between 36 and 46 degrees Fahrenheit. Accidental exposure to heat, freezing temperatures, or direct sunlight can compromise the medication, which may force an unplanned delay while a replacement pen is ordered. If you ever suspect your pen was stored incorrectly, consult your pharmacist before injecting.
Side Effects and What to Watch After a Late Injection
For most patients, reinjecting after a short gap does not significantly increase the risk of serious adverse events. Erenumab has a well-established safety profile, and a brief interruption in dosing does not typically change that.
However, some patients may experience mild injection-site reactions such as redness, swelling, or localized pain when restarting after a gap. This is thought to occur because the body had a partial break from the medication. These reactions are generally short-lived and manageable with a cold compress or basic first aid.
It is worth tracking your migraine activity in the weeks following a missed dose. If you notice a significant rebound in headache frequency or severity, documenting that pattern and sharing it with your prescriber is valuable. Doctronic, which has completed more than 22 million AI consultations, can be a convenient first step for patients who want to quickly assess whether their symptoms warrant a clinician visit before their next scheduled appointment.
When to Reach Out to Your Prescriber or Pharmacist
Not every missed dose requires a phone call, but there are situations where professional input is important. Contact your prescriber if you have missed two or more consecutive monthly doses, as they can help you determine the safest and most effective strategy for getting back on track. A prescriber may also want to assess whether any changes to your overall migraine management plan are needed during that gap.
Reach out if you experience unexpected or severe side effects after reinjecting following an extended break. While uncommon, any reaction that feels unusual compared to your prior experience with erenumab deserves professional evaluation.
Finally, if there is any uncertainty about whether your autoinjector pen was stored properly during a shipping delay or other disruption, ask your pharmacist before using it. Injecting a compromised pen may mean you are not receiving effective medication while also delaying a valid replacement. A quick consultation with your pharmacist or through a platform like Doctronic can save time and help you make the right call.
Frequently Asked Questions
Missing one monthly Aimovig injection is manageable because erenumab has a half-life of about 28 days. Protection does not disappear immediately. Inject the missed dose as soon as you remember, or skip it if your next scheduled dose is very close. Consistent monthly dosing is important for long-term migraine prevention.
No. Double-dosing erenumab is not recommended and does not restore migraine protection any faster. Taking two doses at once may increase the risk of side effects without added benefit. Always return to your regular single monthly dose schedule and consult your prescriber if you are unsure how to get back on track.
Erenumab has a half-life of approximately 28 days, meaning it decreases gradually in your system over time. Meaningful migraine protection may begin to decline around 4 to 6 weeks after a missed injection, though this varies by individual. This long half-life is why a single missed dose is generally less critical than missing a daily oral medication.
Not necessarily right away. Because erenumab stays active in the body for several weeks, migraine frequency may not increase immediately after one missed dose. However, some patients are more sensitive to gaps in dosing. If you notice migraines returning sooner than expected, track that pattern and share it with your prescriber.
Inject the missed dose as soon as you remember, then schedule your next dose one month from that new injection date. If the missed dose was close to your next scheduled date, skip it and continue on your original schedule. After missing multiple doses, talk to your prescriber, as it may take 2 to 3 months to regain full preventive effect.
The Bottom Line
Missing a single dose of erenumab is a manageable situation when you respond promptly and follow the right steps. Inject as soon as you remember, avoid double-dosing, and resume your normal monthly schedule. Because consistent dosing is central to long-term migraine prevention, it is worth setting up reminders and pharmacy automation to prevent future gaps. If you have missed two or more doses or are unsure how to restart, Doctronic offers free AI consultations and $39 video visits available 24/7, with treatment plan guidance that aligns with board-certified physicians 99.2% of the time. This article is informational and is not a medical diagnosis. Confirm with a licensed clinician, especially for new, worsening, or high-risk symptoms.
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