Understanding the Paradox: Can Magnesium Cause Headaches?

October 5, 2025 •

4 min read

According to research, people who experience migraines often have lower levels of magnesium than those who do not suffer from headaches. While it is most famously known as a preventative remedy, some individuals may surprisingly find that magnesium supplementation can cause headaches, particularly if not taken correctly.

Quick Summary

An explainer on the complex relationship between magnesium and headaches. Both magnesium deficiency and excessive intake can trigger headaches. Learn how to identify the cause, find the right balance, and understand the role of supplement types and intake.

Key Points

Dual Effect: Magnesium deficiency can cause headaches, but excessive supplementation can also cause them as a side effect.
Hypermagnesemia Risk: Very high intake of magnesium supplements can lead to a condition called hypermagnesemia, which includes headaches and other symptoms like nausea and muscle weakness.
Gastrointestinal Distress: High intake of some magnesium types, like oxide or citrate, can cause diarrhea and cramping, which may contribute to headache discomfort.
Individual Sensitivity: Responses to magnesium vary from person to person, and some individuals may be more sensitive to changes in their magnesium levels.
Supplement Type Matters: Different forms of magnesium have varying bioavailability. Less absorbable forms (like oxide) are more likely to cause side effects, while more absorbable forms (like glycinate) are gentler on the stomach.
Consult a Professional: It is crucial to speak with a healthcare provider before starting a magnesium supplement, especially if you have pre-existing health conditions like kidney disease.

The Dual Relationship Between Magnesium and Headaches

Magnesium is an essential mineral involved in over 300 biochemical reactions in the body, including nerve function, muscle contraction, and blood pressure regulation. This multifaceted role means that an imbalance in magnesium levels can have wide-ranging effects on your health. While many associate magnesium with preventing headaches, especially migraines, the relationship is complex. For some, headaches are a symptom of a deficiency, while for others, they can be a side effect of excessive intake.

The Link Between Magnesium Deficiency and Headaches

Low magnesium levels, a condition known as hypomagnesemia, can significantly contribute to the onset and severity of headaches. Here's how it can affect your body:

Vascular Changes: Magnesium helps regulate the tone of blood vessels. A deficiency can cause vasoconstriction, or the narrowing of blood vessels in the brain, which can lead to headache pain.
Neurotransmitter Imbalance: Magnesium is crucial for controlling the release of neurotransmitters, the chemical messengers in your brain. A deficiency can disrupt this process, affecting nerve signals and potentially triggering a headache.
Increased Pain Sensitivity: Some studies suggest that low magnesium may heighten pain sensitivity, making individuals more susceptible to headaches and migraines.
Cortical Spreading Depression (CSD): In migraines with aura, CSD is a phenomenon of altered electrical brain activity that is believed to trigger attacks. Low magnesium levels have been linked to promoting CSD.

Can Magnesium Supplements Cause Headaches?

While magnesium is often taken to alleviate headaches, it is possible for supplementation to cause them. This typically occurs in a few scenarios:

Hypermagnesemia: Taking too much magnesium, particularly from supplements, can lead to hypermagnesemia, or excessive magnesium levels in the blood. While rare in healthy individuals, it can happen with high intake and is more common in those with kidney disease, as the kidneys normally excrete excess magnesium. Symptoms of hypermagnesemia include nausea, dizziness, muscle weakness, confusion, and headaches.
Gastrointestinal Distress: High intake of certain magnesium supplements, such as magnesium oxide or citrate, are known to cause gastrointestinal issues like diarrhea and abdominal cramping. For some, this general discomfort and unease can manifest as a secondary headache.
Individual Variability: Everyone's body reacts differently to supplements. Some individuals may simply be more sensitive to magnesium or to sudden changes in intake, experiencing headaches as a result.

Navigating Supplementation and Intake

If you're considering a magnesium supplement for headache prevention, it's vital to proceed with care. Not all magnesium types are created equal, and proper intake plays a critical role.

Here are some tips for navigating supplementation:

Start with Food First: The safest way to increase your magnesium intake is through diet. Focus on magnesium-rich foods like leafy greens, nuts, seeds, whole grains, and legumes.
Consult a Healthcare Provider: Before starting a supplement, it is crucial to talk to a doctor. This is particularly important for individuals with kidney issues or those taking other medications.
Start Low and Go Slow: If you begin supplementing, start with a low intake and gradually increase it. This allows your body to adjust and can minimize side effects.
Monitor Your Body: Pay close attention to how you feel after starting a new supplement. If headaches occur, try lowering the intake or switching to a different form.

Choosing the Right Magnesium Supplement

Different forms of magnesium have varying absorption rates and potential side effects. Choosing the right one can make a significant difference in how your body responds.


Magnesium Form	Bioavailability	Common Uses	Potential Side Effects	Notes
Magnesium Oxide	Low	Constipation relief; often used in migraine research due to high elemental content.	Higher risk of digestive side effects like diarrhea.	Absorption is poor.
Magnesium Citrate	Good	Constipation relief and magnesium supplementation.	Can cause diarrhea, especially with high intake.	Often used for bowel regularity due to its laxative effect.
Magnesium Glycinate	High	Relaxation, sleep support, and gentle on the stomach.	Lower risk of digestive issues.	Preferred for those with sensitive stomachs or focusing on neurological benefits.
Magnesium Malate	Good	Muscle pain relief and energy support.	Generally well-tolerated.	Found to be a more easily absorbed form.

Conclusion

The relationship between magnesium and headaches is a nuanced one. While a deficiency is a well-documented cause of headaches, and supplementation is a common prevention strategy, it's also possible for some people to experience headaches from taking too much. The key is to find the right balance, prioritizing dietary sources and consulting a healthcare professional before adding supplements. By understanding the causes, risks, and different forms of magnesium, you can better navigate your path toward effective headache management.

Disclaimer: The information provided is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before making any decisions about your treatment or changing your healthcare regimen. Your healthcare provider can help determine the best course of action for your individual health needs.

Frequently Asked Questions

While it is less common, a magnesium supplement can cause a headache due to excessive intake leading to hypermagnesemia, or as a secondary effect of gastrointestinal distress caused by high intake.

Hypermagnesemia is a condition where magnesium levels in the blood are too high, usually resulting from excessive supplementation or impaired kidney function. Headaches are one of the possible symptoms, alongside nausea, confusion, and muscle weakness.

Yes, extensive research shows a strong link between magnesium deficiency (hypomagnesemia) and headaches, particularly migraines. Low magnesium levels can affect neurotransmitters and blood vessel function, triggering headache pain.

Magnesium glycinate is often recommended for its high bioavailability and gentle effect on the digestive system, making it less likely to cause side effects like diarrhea and associated headaches compared to forms like magnesium oxide.

To minimize the risk, start with a low intake and increase it gradually, take the supplement with food, stay hydrated, and consider switching to a more easily absorbed form like magnesium glycinate or malate.

If you experience headaches after starting a magnesium supplement, it's best to consult a healthcare provider. They can help you determine if the intake is too high, if a different form is needed, or if another underlying issue is the cause.

The first steps are to assess your intake and consider reducing it. You can also try taking the supplement with food to lessen digestive upset. If symptoms persist, seek medical advice to rule out other causes and determine the best path forward.