Exploring the Link: Does Magnesium Cause Headaches?

October 6, 2025 •

4 min read

Studies have found that many people who experience frequent migraine headaches have lower levels of magnesium than those who don't. This surprising connection raises an important question: if low magnesium causes headaches, does magnesium cause headaches when taken in excess, and what is the optimal balance for symptom management?

Quick Summary

This article explains the complex relationship between magnesium levels and headaches, clarifying why both a deficiency and an excessive intake can potentially cause issues. It covers the mechanisms behind magnesium's role in headache relief, outlines the side effects of over-supplementation, and discusses the best forms and approaches to help manage or prevent headaches effectively.

Key Points

Magnesium Deficiency Link: Lower-than-normal magnesium levels are frequently found in people with chronic headaches, particularly migraines.
Exceeding Dose Risks: Taking excessive amounts of magnesium, especially from supplements, can lead to side effects including headaches as a symptom of hypermagnesemia.
Gastrointestinal Issues: High amounts can cause nausea and diarrhea, which are common side effects that could potentially trigger or worsen headaches.
Supplement Form Matters: Highly bioavailable forms like citrate or glycinate are often better tolerated and may be more effective for headache prevention than less-absorbed forms like oxide.
Kidney Function Is Key: Individuals with kidney problems are at a higher risk of developing dangerously high magnesium levels (hypermagnesemia) from supplements.
Professional Guidance Needed: It is important to consult a healthcare provider before taking magnesium supplements, especially for headache prophylaxis, to ensure safe and appropriate use.

Magnesium is a vital mineral that supports over 300 biochemical reactions in the body, playing a crucial role in nerve function, muscle contraction, and blood pressure regulation. For years, research has explored the connection between magnesium levels and various types of headaches, particularly migraines. While it's widely recommended for its preventive benefits, the relationship is nuanced, and taking too much can have unintended consequences.

The Role of Magnesium in Headache Prevention

For many, magnesium is a valuable tool in headache management. Studies have consistently shown that people with migraines often have lower magnesium levels, both in their blood and brain tissue. By correcting this deficiency, supplementation may lead to a reduction in headache frequency and severity.

Stabilizes Nerve Activity: Magnesium acts as a natural calcium channel antagonist, helping to regulate nerve signals and prevent the overstimulation of nerve cells, which may trigger migraines.
Relaxes Blood Vessels: A deficiency can cause cerebral blood vessels to constrict. Magnesium helps relax these blood vessels, improving blood flow and potentially reducing the risk of a migraine attack.
Reduces Inflammation: It may help to lower levels of CGRP (calcitonin gene-related peptide), a protein involved in migraine pain and inflammation.
Supports Serotonin Function: Low magnesium can affect serotonin levels, a neurotransmitter that influences headaches. Supplementing may help normalize serotonin function.

The Other Side: Can Too Much Magnesium Cause Headaches?

The question "Does magnesium cause headaches?" becomes relevant when considering excessive intake, particularly from supplements. While your kidneys efficiently flush out any excess magnesium from food, high-dose supplements can potentially overwhelm this process and lead to adverse effects.

Hypermagnesemia and Its Symptoms

Hypermagnesemia, the condition of having too much magnesium in the blood, is rare but potentially serious. One of the less common but possible symptoms of severe hypermagnesemia is a headache. Other symptoms include:

Nausea and vomiting
Diarrhea and abdominal cramping
Confusion and drowsiness
Low blood pressure
Muscle weakness and lethargy
Irregular heartbeat

Gastrointestinal Discomfort and Headaches

Even mild over-supplementation, particularly with certain forms like magnesium oxide, is known to cause gastrointestinal side effects such as nausea and diarrhea. Experiencing such discomfort can be a stressor that triggers a headache in itself. For individuals susceptible to gastrointestinal issues, starting with a smaller amount and opting for a more easily absorbed form is often recommended.

Choosing the Right Magnesium Supplement

Not all magnesium supplements are created equal. Different forms have varying levels of bioavailability (how well they are absorbed) and can produce different side effects. Finding the right type is key to both effectiveness and tolerance.


Magnesium Form	Bioavailability	Best For	Potential Side Effects	Notes
Oxide	Low	Migraine prevention (prophylaxis), especially in those with constipation	High risk of diarrhea and GI upset	Generally less expensive, but often requires larger amounts due to poor absorption.
Citrate	High	Migraine prevention, general supplementation	May cause diarrhea in some people, but generally well-tolerated	Often recommended due to good absorption and efficacy.
Glycinate	High	Tension headaches, relaxation, sleep	Gentle on the stomach, very low risk of GI issues	Bound to the amino acid glycine, which also has calming properties.
Threonate	Moderate	Cluster headaches, cognitive function	Less risk of GI issues, some reports of drowsiness	May cross the blood-brain barrier effectively, potentially benefiting neurological conditions.

Ensuring Safe Magnesium Intake and Healthy Levels

For most healthy adults, getting magnesium from food is often the safest way to maintain balanced levels. Excellent dietary sources include:

Leafy green vegetables (e.g., spinach, kale)
Nuts and seeds (e.g., almonds, pumpkin seeds)
Legumes (e.g., beans, lentils)
Whole grains (e.g., brown rice, quinoa)
Dark chocolate

When supplementation is considered necessary, it's vital to discuss appropriate amounts with a healthcare provider and follow their guidance. While a general recommendation exists, specific amounts for migraine prevention may differ and should be managed under medical supervision.

Who is at risk of magnesium toxicity?

Some individuals are more susceptible to the risks of excessive magnesium intake. They include:

Individuals with kidney disease: Impaired kidney function hinders the body's ability to excrete excess magnesium, increasing the risk of hypermagnesemia.
Older people: Kidney function naturally declines with age, potentially increasing susceptibility.
Those on certain medications: Some drugs, such as certain antibiotics and diuretics, can potentially alter magnesium levels.

Conclusion: The Importance of Balance

In summary, the answer to the question "Does magnesium cause headaches?" is not a simple yes or no. A deficiency is a well-established potential cause of migraines and other headaches, while an excess can also lead to adverse effects, including headaches as a symptom of toxicity. The key to successful headache management with magnesium lies in achieving a healthy balance, often with the guidance of a healthcare professional, especially when considering supplemental amounts. By understanding the different forms, being mindful of intake, and recognizing potential risks, individuals can explore the potential benefits of magnesium for headache relief while being aware of the pitfalls of over-supplementation.

For more detailed information on magnesium for migraines, you can consult resources like the American Migraine Foundation at https://americanmigrainefoundation.org/resource-library/magnesium/.

Frequently Asked Questions

Yes, in rare cases, taking excessively high amounts of magnesium supplements can potentially cause headaches. This may be a symptom of hypermagnesemia, or magnesium toxicity. More commonly, high amounts can cause gastrointestinal upset, which might indirectly trigger a headache.

Magnesium citrate is often discussed for migraines due to its good absorption. For tension headaches, magnesium glycinate is a common option because it is easily absorbed and gentle on the stomach. Magnesium threonate is also noted for its potential ability to penetrate the blood-brain barrier.

Yes, it is possible to take too much magnesium from supplements and medications. While your kidneys can handle excess from food, high supplemental amounts can potentially cause side effects like diarrhea, nausea, and abdominal cramping. Extremely high amounts can lead to severe toxicity.

Individuals with kidney disease should be very cautious with magnesium supplements, as their bodies cannot properly excrete excess mineral. People on certain medications like antibiotics and some diuretics should also consult a doctor due to potential interactions.

Some discussions suggest amounts of magnesium for migraine prevention. However, this is often above standard general recommendations and should only be considered under the supervision of a healthcare provider.

For most people, a balanced diet rich in magnesium-containing foods like leafy greens, nuts, seeds, and whole grains is important for overall health. However, to achieve the levels sometimes discussed for migraine prophylaxis, supplementation may be considered, in which case a healthcare provider should be consulted.

Early symptoms of magnesium deficiency (hypomagnesemia) can include fatigue, weakness, nausea, loss of appetite, and headache. As the deficiency worsens, it can lead to muscle cramps, numbness, and tingling.