More on the relationship between hormone therapy and migraine in trans people

I’ve previously written about how feminizing or masculinizing hormone therapy can affect migraines in trans people with this condition. It’s something I’ve experienced myself: as a child, I had frequent migraines with severe pain, nausea, and sensory sensitivity, which almost entirely abated at the onset of puberty and then made a reappearance once I started estrogen at age 23. The association between sex hormones and migraines is well-established, with Pringsheim & Gooren (2004) finding that trans women on HRT had approximately the same prevalence of migraines (26%) as cis women, and a much greater prevalence of migraines than cis men. Cis men have been found to be “more likely to have longer-lasting periods of migraine remission after childhood” (Jamieson, 2017), and cis men who experience migraines tend to have higher levels of estradiol (van Oosterhout et al., 2018).

A chapter in the recent volume Gender and Migraine  offers further details on the mechanisms behind the increased occurrence of migraine in trans women on HRT, the kinds of migraines that trans people experience, and when trans people are most likely to experience them.

Maassen van den Brink & MacGregor (2019) note that high levels of estrogen are associated with migraines that feature auras, a sensory phenomenon that can feature flashing patterns of light or blind spots, while lower levels of estrogen are associated with migraines without auras. The authors observe that trans women taking high doses of estrogen appear to experience an elevated rate of migraines with aura. They speculate that this may be because estrogen increases susceptibility to cortical spreading depression, a neurological phenomenon linked to migraine aura. Estrogen can also affect the serotonin and opioid systems as well as certain neuropeptides, which have been linked to migraine, and notably increases circulating levels of nitric oxide in trans women, which can directly cause migraines. Conversely, testosterone is likely to decrease trans men’s likelihood of migraines.

The authors recommend that transdermal estrogen, such as patches or gel, are preferable to oral estradiol in order to achieve more steady dosing. They suggest that injectable estrogen should be avoided due to the resulting high peaks (producing migraine with aura) falling to low trough levels (producing migraine without aura), but state that this can be avoided with more frequent injections or a reduction in dose. Because aura has been associated with an increased risk of ischemic stroke in trans women, and estrogen may increase the risk of embolism, the authors recommend that trans women “should be counselled about the importance of smoking cessation as well as actively managing other modifiable cardiovascular risk factors.” In trans men, even if menstrual suppression has been achieved with testosterone, ovarian suppression may not be complete, leading to estrogen withdrawal migraines; depot medroxyprogesterone acetate may effectively address this.

The benefits of HRT are something that many trans people are understandably unwilling to go without; at the same time, migraines are just a miserable and unbearable experience. As noted, modifications to one’s HRT regimen can help to make migraines less frequent, and whether you’re trans or cis, there are plenty of effective treatments available. Since my last post on this, monthly injectable CGRP inhibitors for migraine prevention have been further developed into oral CGRP inhibitors taken as needed for aborting migraine attacks. This may provide a greater safety profile than commonly used triptan drugs, which produce a constriction of blood vessels that can be dangerous in those who already have cardiovascular risk factors. The bottom line: if you’ve been having migraines since starting HRT or changing your dose, this is worth discussing with your healthcare provider to find a treatment that works for you. ■