Pharmacology published a study in 2016 looking at medical marijuana for migraines, specifically in relation to its effects on serotonin, with very positive results. You’ll notice that neither study looked at CBD in isolation from other cannabinoids (which is an issue with a lot of research on CBD and pain). Truthfully, the research on CBD alone just isn’t sufficient to make any pronouncements about its effects on headache pain.
In fact, CBD is therapeutic in nature, and will work to manipulate bodily systems at the cellular level to return afflicted organ systems, tissue systems, and even chemical systems in the central nervous system back to a state of health and homeostasis. This is precisely why it has been capable of treating conditions such as depression and anxiety, to chronic physical ailments such as pain, inflammation, arthritis, and more.