How Quickly Does Aimovig Start Working After an Injection?
Aimovig (erenumab) reduces migraine frequency starting around day 7 after the first monthly subcutaneous injection, with full effects often taking up to 1 month. Some patients notice less severe attacks within the first week, but peak benefits typically appear by the fourth week of consistent use.[1]
What Do Clinical Trials Show onset Timeline?
In the pivotal phase 3 trials (PROMISE-1 and PROMISE-2), patients on 70 mg or 140 mg Aimovig saw a 50% or greater reduction in monthly migraine days by week 4. Mean reductions were 3.7 fewer migraine days (70 mg) and 3.7-4.3 fewer (140 mg) versus 1.8-2.3 for placebo. No significant benefit showed in the first week for most.[1][2]
Why Might Results Vary Between Patients?
Factors like migraine severity, prior treatments, and adherence affect speed. About 40-50% of patients respond by month 1; non-responders may need 3 months to assess efficacy. Weight-based dosing (140 mg for those over 70 kg) can influence response rate.[2]
What If I Don't See Results After One Shot?
Guidelines recommend continuing for 3 months before switching. If no 50% reduction in migraine days, consider alternatives like Emgality or Ajovy. Track headaches in a diary to quantify changes accurately.[3]
How Does Aimovig Compare to Other CGRP Migraine Preventives?
| Drug | Dose/Frequency | Typical Onset | Monthly Migraine Day Reduction (Trials) |
|------|----------------|---------------|-----------------------------------------|
| Aimovig | 70-140 mg monthly | 1 week (partial), 1 month (full) | 3.7-4.3 |
| Emgality | 240 mg loading, 120 mg monthly | 1 month | 4.7-5.7 (first month faster in some) |
| Ajovy | 225 mg monthly or 675 mg quarterly | 1 month | 4.6-5.2 |
| Vyepti | 100 mg IV every 3 months | Within 1 week (acute relief possible) | 4.0 (monthly) |
Aimovig acts by blocking the CGRP receptor; others target the ligand, leading to similar but not identical timelines.[2][3]
[1]: Aimovig Prescribing Information (Amgen)
[2]: NEJM Phase 3 Trials (2017)
[3]: American Headache Society Guidelines