Is My CGRP Working? How to Measure CGRP Progress

"Is my CGRP working?" is a reasonable question to ask after months of injections or infusions. The honest answer is that your intuition about this is less reliable than you might expect, because migraines vary naturally month to month and the brain is not good at averaging across time. What you need is objective data, collected before treatment and compared against data collected during treatment. This guide explains exactly how to do that and what the numbers actually mean.

Why You Cannot Rely on Intuition Alone

Memory for pain is compressed and distorted in well-documented ways. After a bad stretch, every month feels terrible. After a good month, the previous bad months feel less severe in memory. If a CGRP preventive gives you a 40 percent reduction in migraine days, you might genuinely feel like "it's not really doing much" because you still have attacks, while missing that you used to have almost twice as many.

The inverse problem also exists. A particularly good month due to low stress, favorable weather, or just normal biological variability can make a treatment look highly effective when it may not be. Confirmation bias is strong: if you wanted the treatment to work, a few good weeks will feel like proof.

Objective tracking sidesteps both of these problems. The data does not remember wrong, and it does not care what you hoped for.

The Baseline Problem: Why It Must Come First

You cannot measure change without knowing where you started. A baseline is your pre-treatment migraine frequency, typically measured over three months of consistent daily logging before you begin a new preventive.

If you started a CGRP preventive without an established baseline, you still have options:

• Use pharmacy records. Acute medication prescription fills before treatment give a rough proxy for attack frequency.
• Use prior medical records. If a neurologist documented your migraine frequency in an earlier visit, that note can serve as baseline documentation.
• Reconstruct from memory with caution. This is the least reliable option, but "I was having approximately 15 days per month before starting" is still better than no baseline at all.

Going forward, the first thing to establish before any new preventive is three months of prospective daily logging. It takes almost no time per day but makes every subsequent treatment decision more grounded. See monthly migraine days for how to count correctly.

The Metrics That Tell the Real Story

Monthly migraine days is the headline number, but it is not the only signal. A complete picture of CGRP progress includes:

Monthly migraine day reduction. Calculate your average monthly migraine days for the three months before treatment, then compare to your average for each subsequent three-month period. A 50 percent or greater reduction is the benchmark used in clinical trials and commonly required by insurance for prior authorization renewal.

Breakthrough medication use days. Track how many days per month you take an acute medication (triptan, CGRP acute, NSAID used for attacks). This number should decrease as a preventive takes effect. Unchanged or increasing acute medication use despite claimed improvement is a red flag worth discussing with your prescriber.

MIDAS and HIT-6 scores. These validated questionnaires measure migraine-related disability and headache impact, respectively. They give your prescriber a standardized way to compare your functional impairment before and during treatment. If your migraine day count drops modestly but your MIDAS score drops substantially, that is meaningful. The scores are explained in full in MIDAS and HIT-6 explained.

Severity trends. If attacks are less severe on treatment even when they still occur, that is a real outcome worth tracking. A day that used to put you in a dark room for 12 hours but now resolves to a manageable level after two hours is a meaningful change, even if it still registers as a migraine day.

Aura frequency. For people with migraine with aura, tracking whether auras decrease, remain the same, or increase is additional clinical data.

What Realistic Timelines Look Like

CGRP preventives generally do not work immediately. The neurological mechanisms involved take time to produce measurable changes in attack frequency. In general terms:

• Month one: Some patients notice improvement; many do not. Month-one data is real but noisy.
• Month two to three: The signal becomes clearer. This is when most prescribers start evaluating response.
• Month four to six: For partial responders, some additional benefit may still accumulate.

Natural migraine variability means that one good month does not confirm efficacy and one bad month does not refute it. That is why three-month averages are more meaningful than individual months. A single bad month due to illness, a major life stressor, or a hormonal surge is not evidence a treatment failed. A flat or worsening three-month average is.

If you are at the three-month mark with no meaningful change in any of the metrics above, that is objective information. Bring your log to your prescriber and discuss whether to continue, adjust the dose, or consider a different approach.

Organizing the Comparison

The format that works best for a prescriber review:

You do not need to build this table manually. If you have been logging daily in a structured app, this is a summary report, not a data entry project.

The CGRP prior authorization renewal process often requires exactly this kind of before-and-after comparison. Insurance reviewers and prescribers both need the baseline versus current monthly migraine days, the percentage reduction, and disability scores presented in a usable format. See the CGRP prior authorization renewal guide for what documentation is typically required.

When the Numbers Are Ambiguous

A 30 percent reduction in migraine days is neither a clear success nor a clear failure. What matters in this zone:

• Is your disability score improving even if the day count is not dropping dramatically?
• Are attacks resolving faster with acute medication?
• Have you had fewer emergency visits or missed work days?
• Is your quality of life on non-migraine days better?

These are legitimate factors to weigh with your prescriber. The 50 percent threshold is a useful benchmark, not a hard biological law. Some patients live meaningfully better lives with a 35 percent reduction because their attacks are less severe or their most disabling attacks are the ones that decreased.

If the numbers are flat across all measures after an adequate trial, that is also a clear signal. Not every preventive works for every patient, and the data is more actionable than a guess.

Migraine Tracker: CGRP Log is built around this exact workflow. It calculates your monthly migraine day counts, tracks breakthrough medication use, logs MIDAS and HIT-6 scores, and generates a one-page renewal report showing your baseline versus current data and percent reduction. The hard part of measuring CGRP progress, which is collecting consistent data over months and then organizing it, is handled automatically so you can focus on the conversation with your doctor.