Your migraines won't stop, Your genes may be why.

MTHFR encodes an enzyme that catalyzes one of the most critical steps in cellular metabolism: converting dietary folate and B12 into their active forms so your cells can produce energy and regulate inflammation. It also influences nitric oxide production, the molecule that keeps your cerebral blood vessels relaxed and responsive.

The C677T variant, carried by roughly 40% of people with European ancestry, reduces MTHFR enzyme efficiency by 40 to 70%. Your cells can’t convert B vitamins fast enough to meet demand, and your nitric oxide production drops. This creates two migraine problems at once: impaired mitochondrial energy production in brain cells makes them more excitable, and reduced vascular tone makes blood vessels less stable and more prone to the vasodilation cycles that trigger migraine pain.

You might feel this as migraines that cluster during times of high stress or illness, when your energy demand spikes. Or as migraines that come with particular intensity during your menstrual cycle, when hormonal shifts demand more methylation capacity. The migraine doesn’t resolve quickly because the underlying energy deficit persists. You’re essentially asking a depleted mitochondrion to regulate its own pain signals.

COMT clears the catecholamine neurotransmitters (dopamine, norepinephrine, epinephrine) from your synapses. These molecules are central to pain modulation. Your brain uses them to suppress pain signals coming from the trigeminal nerve, the nerve system that fires during migraines. COMT also influences how sensitive your pain-processing circuits become.

The Val158Met variant, present in roughly 25% of people as a homozygous slow variant, slows COMT enzyme activity significantly. Catecholamines accumulate in your synapses and stay there longer than they should. This sounds like it might increase pain suppression, but it actually does the opposite: prolonged catecholamine signaling leads to receptor downregulation and sensitization of pain circuits. Your brain becomes hyperresponsive to pain signals. Migraines get worse, they last longer, and the medication you take to abort them works less effectively because your pain threshold is lower to begin with.

You might notice your migraines worsen when you consume caffeine (which raises catecholamine levels further), or that your migraine pain feels unusually intense and resistant to your usual abortive medication. The slow COMT variant essentially amplifies pain signaling in the trigeminal system, making each migraine harder to shut down.

SLC6A4 encodes the serotonin transporter, the protein that recycles serotonin from the synapse back into the presynaptic neuron so it can be reused or broken down. Serotonin is one of the master regulators of migraine pathophysiology. Low serotonin availability triggers the vasoconstriction and vasodilation cycles that initiate migraine pain. It also worsens central pain sensitization, meaning your brain becomes increasingly responsive to pain signals as migraine progresses.

The 5-HTTLPR short allele, carried by roughly 40% of the population in at least one copy, reduces the efficiency of the serotonin transporter. Serotonin gets reuptaken more slowly, but it also gets degraded faster by monoamine oxidase, leaving you with less total serotonin availability over time. This is especially pronounced during times of stress or in the luteal phase of the menstrual cycle, when serotonin metabolism accelerates. The result is a migraine threshold that’s chronically lowered and migraine duration that stretches because the serotonin system is depleted.

You might notice your migraines are worse during stressful periods or that they cluster in the week before your period. You might find that migraines come in waves rather than isolated events. This is the serotonin system struggling to maintain equilibrium and failing intermittently. Each migraine depletes serotonin further, making the next one easier to trigger.

NOS3 encodes endothelial nitric oxide synthase, the enzyme that produces nitric oxide in your blood vessels. Nitric oxide keeps your cerebral blood vessels relaxed, responsive, and able to regulate blood flow dynamically. When blood vessels lose this ability to dilate and constrict smoothly, they become hyperreactive to triggers. This hyperreactivity is the vascular half of migraine pathophysiology. Without adequate nitric oxide signaling, your cerebral blood vessels are primed to overreact.

The Glu298Asp variant (rs1799983), present in roughly 30 to 40% of the population, reduces the amount of nitric oxide your endothelial cells produce. Your cerebral blood vessels lose tone and become more susceptible to the vasodilation cycles that trigger and perpetuate migraine pain. This makes your migraines not just more frequent but more resistant to resolution. Once a migraine vasodilation cycle starts, your blood vessels have less biochemical brake to stop it. The migraine persists longer because the vascular machinery that should naturally resolve the dilation is compromised.

You might experience your migraines as throbbing pain that feels unusually vascular, or notice that your migraines respond poorly to vasoconstrictors like triptans. You might also notice that your migraines are worse during periods of poor cardiovascular fitness or when you’re not exercising regularly, because exercise is one of the main ways your body upregulates nitric oxide production.

AOC1 encodes amine oxidase, copper-containing 1, an enzyme that breaks down histamine in the bloodstream and vascular tissue. Histamine is a powerful vasodilator. When it accumulates in your blood vessel walls, it triggers the very dilation cascades that cause migraine pain. During mast cell activation (which happens during stress, immune challenges, or allergic reactions), histamine floods your circulation. If your AOC1 enzyme is less efficient, histamine lingers, and blood vessels stay dilated longer.

Variants in AOC1 that reduce enzyme activity are present in roughly 20 to 30% of the population, with higher prevalence in certain ancestry groups. Histamine accumulates in your vascular tissue and perpetuates the vasodilation phase of migraine. This means your migraine doesn’t resolve on its own because the histamine that triggered it is still present, still signaling vessel dilation. You’re stuck in the migraine cycle longer. Your standard abortive medication might work temporarily, but as soon as the drug wears off, the histamine signal is still there.

You might notice your migraines are worse on high-histamine days (when you eat fermented foods, aged cheeses, cured meats, or alcohol), during allergy season, or after stressful events that trigger mast cell activation. You might also notice your migraines come with unusual flushing, sweating, or other signs of vasodilation and mast cell involvement.

TNF encodes tumor necrosis factor alpha, a powerful pro-inflammatory cytokine that your immune system releases during times of stress, infection, or tissue damage. In moderation, TNF is protective. But when it’s overproduced, it drives neuroinflammation in the brain and sensitizes pain pathways in the trigeminal system. TNF also increases vascular permeability, allowing more immune molecules to cross the blood-brain barrier, which amplifies migraine pain.

Certain TNF promoter variants increase TNF production under stress or immune challenge. Your brain becomes more neuroinflamed, your trigeminal pain pathways become more sensitized, and your migraine duration extends because the underlying inflammation isn’t resolving. This is especially pronounced if you’re dealing with chronic stress, ongoing infections, or autoimmune activation. Each migraine triggers more TNF, which sensitizes your pain circuits further, making the next migraine easier to trigger and harder to stop.

You might notice your migraines are worse during times of high stress, illness, or immune challenge. You might find that standard pain medications are less effective than they used to be, or that you’re getting migraines more frequently even without obvious new triggers. This is neuroinflammation compounding over time, progressively lowering your migraine threshold.