Mar 10 2010

Magnesium for Migraine

I received the following question from an SGU listener:

Recently when I visited a neurologists with my daughter to seek help for her migraines the doctor prescribed something that caught me off guard and in my research since the visit I still have not convinced myself of the validity. The doctor told my daughter she should start taking magnesium supplements. The doctor told her this would serve as a natural muscle relaxant.
I have been listening to your podcast for about 6 months now and enjoy it very much. I enjoy the entire crew and would really like your team’s take on the Migraine and Magnesium relation.

This is an excellent question, and reinforces the notion that science-based medicine is not about a list of acceptable beliefs or modalities – it is about method. There is nothing inherently implausible or unscientific about using vitamins, minerals, or other nutrients to address diseases or symptoms. All that matters is the science.

However, the current state of loose regulation did result in an explosion of the supplement industry, with a multiplication of dubious claims. This had the additional consequence of drowning out legitimate nutritional advice with all the nonsense, in a “boy who cried wolf” phenomenon. Now the skeptical consumer is and should be wary of any and all supplement claims.

Magnesium for migraine is a plausible hypothesis. Magnesium can affect both regulation of blood flow and neuronal function – both of which are physiological factors important in migraine. There is evidence that magnesium deficiency is common, and is more common in migraine patients than non-migraine sufferers.

But the basic science is complex, and there is evidence that low magnesium in brain tissue may be a side effect, and not a cause, of the physiological mechanisms of migraine. So the bottom line is that magnesium as a treatment for migraine is plausible, but there are still unknowns.

The clinical evidence needs to be divided into specific clinical claims: magnesium as a treatment for children vs adults, migraine with aura vs migraine without aura, acute treatment of migraine attacks vs migraine prophylaxis, and treatment of menstrual migraines.

Here is my quick summary of the evidence: There is preliminary evidence only in children, and more research is needed. Treatment of acute attacks with IV magnesium sulfate has mixed evidence, but more positive than negative. One study showed, however, that it can decrease the effectiveness of medication for nausea, often given to treat the nausea of severe migraines.

There is more evidence for migraine with aura than without, but probably not enough to make a critical difference. The best evidence is for menstrual migraines.

Overall the evidence for prophylaxis shows a small but significant effect. Evidence is still preliminary, and large definitive trials are needed to fully settle the question.The effect seems to be smaller than for other nutritional interventions for migraine, specifically vitamin B2 and Coenyzme Q10, and all the supplements are less effective than the best prescription medications.

As a neurologist who treats migraine frequently, I also have experience using magnesium. This is how I put it all together: Most of my patients have not noticed a significant improvement with magnesium. While it is safe, in the doses used for migraines (400-600mg per day) diarrhea can be a significant side effect, and many of my patients stopped using it or had to decrease the dose for that reason.

While the evidence is preliminary, it tends to be positive and so magnesium is a plausible and generally benign treatment option  (if you don’t get diarrhea). It may have a role more as adjunctive treatment (in addition to other treatment) rather than stand-alone treatment because the effect is modest.

Typically I will check the magnesium level in patients with migraine and supplement magnesium if it is low. These patients may represent a subset that responds to magnesium, and in any case they are low in magnesium and probably should be supplemented anyway.

Overall magnesium has a minor role to play in the management of migraine. We could benefit from larger studies to more definitively clarify its role in the various clinical situations I outlined above, primarily because it is inexpensive and relatively benign.

I do not think that the evidence supports using magnesium as a primary treatment for migraine before other more effective treatments. However, some patients may wish to give it a try in the hopes of avoiding medication, and that is reasonable.

The use of magnesium in migraine is a good example of how a science-based practitioner might incorporate benign and plausible treatments but with only preliminary evidence into their practice.

12 responses so far

12 Responses to “Magnesium for Migraine”

  1. ballookeyon 10 Mar 2010 at 2:39 pm

    This is really helpful! I’m so glad you mentioned the Coenyzme Q10 supplement because a neurologist recommended that to my husband for his headaches. I went ahead and bought it for him, but I’ve never been sure if the doctor was maybe a little quack-y. My husband liked the guy very much with regard to the rest of his care pertaining to a serious head injury, so I went with it and indeed, my husband has had far fewer headaches on it. But since he got hit in the head with a car, I don’t take anything he reports at face value… 😉

  2. CivilUnreston 10 Mar 2010 at 6:01 pm

    Dr. Novella, that was an awesome example of how doctors are not just medicine prescribing automatons (as some woo-ers would have us believe), but excellent critical thinkers. Working in basic research, I have the luxury of large sample sizes and big populations to work with when investigating a biological problem. In your clinical practice you make due with an n of 1. Each patient is treated as an individual, and if they are unhappy with the “standard” treatment, a good doctor will work with them to find what works.

    It just goes to show that the CAM people don’t have a lockdown on the “treating the whole person…as an individual!” thing.

    Unless you’re just a shill for the magnesium industry (or, as I like to call it, Big Maggie)

  3. Eon 10 Mar 2010 at 7:49 pm

    “There is nothing inherently implausible or unscientific about using vitamins, minerals, or other nutrients to address diseases or symptoms. All that matters is the science.”

    As someone who takes calcium/calcitriol (vitamin D) for lingering post thyroid/parathyroid surgery hypocalcemia, I can appreciate this kind of sentiment being reiterated. Though I realize my scenario goes beyond the scope of plausible (since the worth of what I’m taking is confirmed by blood tests), still, it’s nice to hear about how supplements can indeed have value. Especially when they’re used within the confines of a responsible doctor-patient relationship.

    BTW: Pertaining to the supplements I take, magnesium happens to be a periodic adjunct.

    Thank you.

  4. Joelon 10 Mar 2010 at 9:12 pm

    Careful CivilUnrest,

    Next thing you know there will be a Magnesium Militia pointing to Mg’s reaction with water and claiming that physicians and “Big Maggie” are trying to blow up our children.

    Just saying, I don’t know how these things start.

  5. Neuroskepticon 11 Mar 2010 at 3:06 am

    Joel: Heh.

    The Nazis used Magnesium to make their airplanes and incendiary BOMBS! And now Steven Novella wants to give it to your kids! Mommies Against Mg!

  6. Draalon 11 Mar 2010 at 6:59 am

    or magnesium is a metal that starts with the letter ‘m’, just like mercury. He’s trying to give migraine sufferer’s autism! Have you even read the MSDS for magnesium phosphate? And I quote, “May be harmful if swallowed.”

  7. cloudskimmeron 15 Mar 2010 at 12:23 pm

    Since DSHEA has removed supplements from any regulation on efficacy, quality, content and safety until they kill or seriously harm someone, what assurance do I have that the bottle of whatever supplement I purchase even contains what it says on the label? ConsumerLab’s testing helps, but only if I believe the company maintains that level of quality, and the substance is well-defined. And if the substance is ground up herbs, there seems to be no standard, since the “effective ingredient” may not even be defined.

    Sometimes it’s said that you should pick a manufacturer you trust. With no regulation, how can any of them be trusted? Does the daily vitamin pill have everything on the label? Is it in bioavailable form?

    So, when the Doctor tells you to take magnesium, how can that be done safely and with confidence? Or CoQ? or vitamin D? What form should it take and what dose is appropriate?

  8. Abbson 15 Mar 2010 at 1:58 pm

    As a rule of thumb, organic magnesium (e.g. magnesium citrate, glycinate, etc.) is the best form to take rather than the inorganic magnesium oxide because it’s more bioavailable. Inorganic magnesium is cheaper and therefore it’s more widely used even though it’s less bio active.

  9. Abbson 15 Mar 2010 at 2:02 pm

    As for Vitamin D…the RDA of 400 IUs is incredibly low. A blood test should be used to determine your vitamin D status…which is now being suggested to be between 50-100 ng/mol. 400 IUs per day will never get you to that serum concentration. More realistically, 5,000-10,000 IUs daily, depending on the person. Also, as a supplement, D3 is far superior to D2.

  10. Draalon 18 Mar 2010 at 7:59 am

    If taken, Coenzyme Q10 should be bought as an oil mixture (often in a gel capsule) because the solubility of CoQ10 is so low in water. CoQ6, 7, 8 , and 9 are useless as the human body does not use them; they are prepared from microorganisms that can use them but mammals cannot.

  11. ccbowerson 19 Mar 2010 at 11:10 am

    “Also, as a supplement, D3 is far superior to D2.”


    Most of what you said is beyond the evidence. 5,000 to 10,000 IUs is excessive. There is such a thing as too little sun… get outside a couple times a week and you’ll get your thousands of IUs

  12. mrsdon 12 Aug 2012 at 5:34 am

    I find that taking magnesium with my panadol+codeine really works. It seems to assist the relaxation of the muscles as well as the bloodflow is assisted. Still trying to find out the corret dosage of magnesium though as the bottle I bought recommended 1500mg!!! Finding now that could have been slightly excessive. However, have not suffered diarrea, could be the codeine?

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