The supplements listed below are commonly used for headaches and have been evaluated by the American Academy of Neurology and the American Headache Society (AAN/AHS) in their 2012 guidelines on alternative treatments for migraines.
Butterbur. At least two clinical trials suggest that the herb butterbur (Petasites hybridus), in the daisy family, can help decrease the frequency, duration, and intensity of migraines when taken as a preventive. It is the only supplement rated “established as effective” by AAN/AHS. There’s no evidence it helps once a migraine has developed. However, butterbur contains toxic substances (pyrrolizidine alkaloids), so the extracts used in supplements must be carefully purified to remove the toxins. The most studied butterbur supplement, Petadolex from Germany, has no detectable levels of alkaloids. Other brands may not be safe. Don’t use butterbur if you are pregnant, nursing, or allergic to plants in the daisy family.
Feverfew. This common flower (Tanacetum parthenium), also in the daisy family, is rated as “probably effective” by AAN/AHS, which singled out an extract called MIG-99. Feverfew may reduce inflammation as well as levels of the hormone-like substances known as prostaglandins; among other effects, some prostaglandins play a role in producing pain sensations and migraine. A few small studies have shown that feverfew can help prevent (not relieve) migraines.
Magnesium. AAN/AHS rated magnesium supplements as “probably effective” for migraine prevention. Researchers have found that people with migraines tend to have low brain magnesium levels during an attack and are more likely to have low magnesium overall. Two studies from the 1990s found that supplements helped reduce the frequency of attacks, though another study did not. Recommended doses range from 400 to 600 milligrams a day (the adult Recommended Dietary Allowance, or RDA, is 310 to 420 milligrams a day). People with kidney disease should not take magnesium supplements except under medical direction.
Riboflavin. This B vitamin has also been rated as “probably effective” by AAN/AHS. Studies have found it effective at megadoses of 400 milligrams a day. That’s about 300 times the daily RDA.
Coenzyme Q-10 (CoQ10). A small study in Neurology in 2005 found that this vitamin-like substance, at 300 milligrams a day, helped reduce the number of days per year people suffered from migraines. But the AAN/AHS rated it lower, as only “possibly effective.”
Also see 4 Nondrug Options for Headaches.