Supplements and migraine
Magnesium for Migraine: Does It Work, and What to Check First
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed September 20267 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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Magnesium carries the strongest formal evidence grade of any migraine supplement. The American Headache Society and the American Academy of Neurology rate it Level B, meaning probably effective. Studies usually use 400 to 600 mg a day. Benefit concentrates in people who are low, so checking your own level first is the sensible order.
See what to check first →As of September 2026. Magnesium is the supplement people are pointed to most often for migraine, in podcast routines and in the supplement aisle. The grade behind it is real. The part almost nobody mentions is that the studied dose sits above the line the NHS draws for magnesium supplements, and that the benefit is concentrated in people who were short of it.
1. Does magnesium actually help migraine?
Probably, a little. And it holds the best formal grade of any supplement in this area, which is more than can be said for most things sold for head pain. In 2012 two headache bodies reviewed the prevention evidence and put a number on it.
“In 2012, the American Headache Society and the American Academy of Neurology reviewed the studies on medications used for migraine prevention and gave magnesium a Level B rating; that is, it is probably effective.”
— American Migraine Foundation, Magnesium and Migraine
Read that grade for what it is. Level B is not Level A. It means probably effective on evidence that is reasonable rather than settled, and it is the ceiling for any nutrient here. The trials were mostly small.
One more thing worth saying plainly. Magnesium is a food supplement, not a migraine medicine, and it does not replace care from a qualified clinician. If your attacks are frequent, disabling or changing in pattern, that is a GP conversation rather than a shopping decision.
2. The dose, and the line the NHS draws
Here is the detail the supplement blogs leave out. The same American Migraine Foundation resource gives the dose the trials used:
- The studied migraine dose is 400 to 600 mg a day, usually as magnesium oxide.
- The NHS puts the daily need much lower, at around 300 mg for men and 270 mg for women, mostly from food.
- The NHS also says 400 mg or less a day from supplements is unlikely to cause harm, while higher doses can cause diarrhoea.
Put those together and the point lands. The migraine dose range starts exactly where the NHS comfort line for supplements ends, and the top of it sits well above. That is not a reason to rule magnesium out. It is a reason to involve a pharmacist or a qualified clinician before you take 600 mg a day for months, rather than deciding it alone in a shop.
Our guide to taking too much magnesium walks through what each step above that line actually does to you.
3. Why check your level before you commit
Topping up a mineral mainly helps when you were short of it. That is the single biggest thing separating people who find magnesium useful from people who find it does nothing. So the useful question is not whether magnesium works in general. It is whether you are low.
A blood test answers that, with one honest caveat. A standard test reads serum magnesium, and only about 1% of your body's magnesium is in your blood. So a normal result does not fully rule out depletion. A low one still turns a guess into a number.
Our magnesium blood test guide covers serum against the alternatives, and normal magnesium levels explains how to read the result you get.
Two Helvy panels measure magnesium at home from a finger-prick sample:
- General Energy & Wellness (£149) reads magnesium inside 17 markers, with thyroid (TSH), free T4, vitamin B12 and vitamin D alongside it.
- Vitamins & Minerals (£159) reads magnesium with a full iron workup, plus vitamin B12, folate and vitamin D.
Either way you learn something. Low, and a supplement has a real chance of helping. Fine, and you have saved the money and know to look elsewhere.
4. Which form, and what it costs you
If a test says you are low, the form matters for absorption and for your gut, not for any migraine-specific magic:
- Oxide. What most of the migraine trials used. Cheap, poorly absorbed, and the most likely to loosen your bowels at 400 mg and above.
- Citrate. Better absorbed and still cheap, but it also draws water into the gut at higher doses.
- Glycinate. Well absorbed and the gentlest on the stomach, which matters at a dose you plan to hold for months.
There is an awkward tension there. The form with the trial evidence is the one most likely to upset your gut. Our comparison of glycinate against citrate and our overview of which magnesium to take go through the trade-off.
5. What else behind frequent migraine shows up in blood
Magnesium is one candidate, not the only one. Several common things can drive or worsen frequent head pain, and a blood test measures them rather than guessing at them. Low iron stores, an underactive or overactive thyroid, low vitamin B12 and low vitamin D all come up in this picture.
That is worth a look before you settle on one mineral. Our headache and migraine blood test guide maps the full marker set, including what a full blood count adds. If your attacks got worse in your forties, the hormonal shift is its own story, covered in migraines in perimenopause. The energy and fatigue hub collects the rest.
One safety note. A sudden, severe headache unlike anything you have had before, or a headache with fever, weakness, confusion or a stiff neck, needs urgent medical help rather than a supplement or a blood test.
READY TO TEST?
Find out whether you are actually low before you commit to 600 mg
Magnesium has the best grade of any migraine supplement, and it works best in people who were short of it. Helvy's home finger-prick General Energy & Wellness panel reads your magnesium alongside thyroid, B12 and vitamin D, so your next step starts from a number.
Frequently asked questions
Does magnesium help migraine?
It has the strongest formal grade of any supplement used here. The American Headache Society and the American Academy of Neurology rated magnesium Level B in 2012, meaning probably effective. That is short of Level A, and the trials were mostly small. Magnesium is a food supplement rather than a migraine medicine, so frequent or disabling attacks are still a conversation with a qualified clinician.
How much magnesium is used for migraine?
The American Migraine Foundation gives the studied dose as 400 to 600 mg a day, usually as magnesium oxide. Note that the NHS says 400 mg or less a day from supplements is unlikely to cause harm, and that higher doses can cause diarrhoea. So the migraine range begins at the top of the NHS line. Talk to a pharmacist or a qualified clinician before holding a dose in that range.
Should I test my magnesium before taking it for migraine?
It is the sensible order, because the benefit is concentrated in people who are low. One caveat: a standard test reads serum magnesium, and only about 1% of your body's magnesium sits in your blood, so a normal result does not fully rule out depletion. Helvy's General Energy & Wellness panel reads magnesium within 17 markers, and Vitamins & Minerals reads it alongside a full iron workup.
Which magnesium is best for migraine?
Oxide is what most trials used, but it is poorly absorbed and the most likely to loosen your bowels. Citrate absorbs better and costs little. Glycinate is the gentlest on the stomach, which matters at a dose you intend to hold for months. The form changes absorption and side effects rather than adding any migraine-specific effect.
Related guides
Headache & Migraine Blood Test UK
The full marker set behind chronic head pain, and what each result rules in or out.
Magnesium Blood Test UK
Serum against the alternatives, and how to read whether you are genuinely low.
Can You Take Too Much Magnesium?
What each step above the NHS supplement line actually does to you.
Migraines Worse in Your 40s?
Why attacks often change in perimenopause, and the hormones worth reading.
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