Most people taking Emgality notice fewer migraine days within the first month of treatment. Clinical trials consistently show a statistically significant reduction in monthly migraine days starting at month one, for both episodic and chronic migraine. That said, the full benefit builds over time, and many people continue to improve through months three to six.
Why the First Month Matters
Emgality works by binding to a protein called CGRP, which plays a central role in triggering migraine attacks. By neutralizing CGRP before it can activate pain pathways, the medication reduces migraine frequency rather than treating attacks after they start. This is a preventive approach, so it works in the background between injections.
Your first dose is a loading dose of 240 mg (two injections at once), which is double the regular monthly dose of 120 mg. This isn’t arbitrary. The loading dose brings the medication to its full working concentration in your bloodstream immediately, rather than making you wait several months to build up. Without it, reaching that same concentration would take roughly four monthly doses. So the loading dose essentially fast-tracks your results by about three months.
What Clinical Trials Show Month by Month
In the REGAIN trial, which studied Emgality in people with chronic migraine (15 or more headache days per month), patients experienced significantly fewer migraine days compared to placebo starting in month one. The EVOLVE-1 and EVOLVE-2 trials, which focused on episodic migraine (4 to 14 migraine days per month), found the same early benefit.
The improvements don’t plateau after that first month. Across four major clinical trials, Emgality continued reducing monthly migraine days over three to six months of treatment. For people with episodic migraine, benefits were tracked over six months and remained consistent throughout. For chronic migraine, the effect held steady across the three-month study period. Many doctors and insurers look for at least a 50% reduction in monthly migraine days as the benchmark for whether the medication is working well enough to continue.
Not everyone hits that 50% threshold in month one. Some people see a modest improvement early on that deepens with continued use. The clinical data doesn’t identify a distinct group of “late responders,” but the gradual improvement pattern means it’s reasonable to give the medication at least three months before deciding it isn’t helping.
What to Realistically Expect
Emgality is not a cure for migraine, and it won’t eliminate every attack. In clinical trials, the average reduction was several migraine days per month compared to placebo. That might sound modest on paper, but for someone going from 10 or 15 migraine days a month down to five or six, the quality-of-life difference is significant.
Some people respond dramatically and others see only a partial benefit. If you’ve been on Emgality for a full three months without any noticeable change in migraine frequency or severity, that’s a reasonable point to reassess with your prescriber. But dropping the medication after just one or two doses because you still had migraines would be premature. The loading dose gets the drug into your system quickly, but your brain’s migraine threshold may take longer to stabilize.
How the Injection Schedule Works
After the initial loading dose of 240 mg (two 120 mg injections given on the same day), you switch to a single 120 mg injection once a month. It’s a subcutaneous shot, meaning you inject it just under the skin of your abdomen, thigh, or the back of your upper arm. Most people self-inject at home using a prefilled pen or syringe.
Consistency matters. Because the medication works by keeping CGRP levels suppressed between doses, skipping a month or spacing injections further apart can reduce its effectiveness. The drug has a long half-life, so missing one dose by a few days isn’t a crisis, but staying on a regular monthly schedule gives you the best chance of sustained results.
Factors That Affect Your Response Time
Several things can influence how quickly you notice a difference. People with episodic migraine (fewer baseline migraine days) sometimes notice improvements more clearly because each migraine-free day is a larger percentage change. People with chronic migraine may take longer to feel like the medication is “working” simply because they started from a higher number of migraine days, even if the absolute reduction is similar.
Your migraine triggers also play a role. Emgality targets one specific pathway, so if your migraines are driven heavily by CGRP activity, you’re more likely to respond quickly and robustly. If other factors like hormonal fluctuations, sleep disruption, or medication overuse are contributing, you may need to address those alongside the injection for the full benefit to show. Keeping a migraine diary during your first three months on Emgality gives you an objective record to compare against your baseline, which is more reliable than trying to remember how things felt a month ago.