I first learned about the importance of magnesium in one of my undergrad nutrition classes.

What surprised me the most was learning about the number of roles magnesium plays in our bodies. Your body requires magnesium for more than 300 enzymatic reactions! Plus, a deficiency or suboptimal intake can have a drastic effect on your health (1).

For example, a low magnesium intake has been associated with high blood pressure, heart disease, diabetes, and even sleep problems (1).

Although magnesium is found in a wide variety of foods — especially nuts, legumes, and whole grains — supplements can offer benefits, particularly for people with low magnesium intake.

However, with magnesium supplements available in a wide variety of forms and dosages, choosing one isn’t always easy.

This article looks at the benefits and side effects of magnesium supplements and highlights the various forms and dosages.

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Magnesium is the fourth most abundant mineral in your body. In fact, your body can’t work properly without it (2).

The nutrient is essential for hundreds of metabolic processes and many other important bodily functions, from producing energy to building important proteins (3).

Dietary sources of magnesium include legumes, nuts, seeds, and green leafy vegetables. Smaller amounts are found in meat and fish.

However, despite its importance, studies show that almost 50% of people in Europe and the United States don’t get enough of this essential mineral (2, 4).

Moreover, low levels of magnesium are linked to a number of health conditions, such as type 2 diabetes, heart disease, and Alzheimer’s disease (2).

Summary

Magnesium is a mineral your body needs to function properly. Many people don’t consume enough of this essential nutrient, which is found in foods such as nuts, leafy greens, legumes, and seeds.

Getting enough magnesium is important to keep your body working at its best.

Though it’s possible to get adequate amounts of this mineral from your diet, taking a supplement may be helpful if you have difficulty meeting your magnesium needs through food or if you have a deficiency.

Taking a magnesium supplement to address a deficiency has been linked to health benefits. These include improvements in blood pressure, mood, and blood sugar management, as well as a lower risk of developing health conditions such as heart disease.

May help reduce blood pressure

Taking magnesium supplements may help reduce blood pressure levels (5).

Studies show that people with high blood pressure may see improvements when supplementing this mineral (6, 7).

In fact, a review of 34 studies concluded that taking around 350 mg per day of magnesium for an average of 3 months significantly reduced systolic blood pressure (the top number) by 2 mm Hg and diastolic blood pressure (the bottom number) by 1.78 mm Hg (8).

Similarly, a review of 7 studies associated supplementing with a dose of 300 mg or more of magnesium daily for at least 12 weeks with a 5.78 mm Hg drop in systolic and a 2.5 mm Hg drop in diastolic blood pressure in participants with type 2 diabetes (9).

May improve sleep

Magnesium plays an important role in sleep.

People with low magnesium levels are more likely to experience sleep problems, such as difficulties falling or staying asleep, and magnesium supplements have been shown to improve sleep.

A review of 3 studies among older adults found that supplementing with 320–720 mg of magnesium daily for up to 8 weeks decreased the time it took them to fall asleep and increased total sleep time compared with placebo (10).

Other studies have found similar results, demonstrating that magnesium supplementation may help people fall asleep quicker and stay asleep longer — especially older adults (11, 12).

May improve mood

Some studies link low levels of magnesium with depression, and this has led researchers to wonder whether supplementing with this mineral could help treat this condition (13).

A 6-week randomized controlled trial including participants with depression found that 500 mg of magnesium daily alleviated depressive and anxiety symptoms in as little as 2 weeks (14).

Another 6-week study among 126 people with mild or moderate depression observed that those who took 248 mg per day of magnesium alongside their normal treatment reported a significant improvement in depression symptoms (15).

However, these studies were not blinded, meaning that the participants knew that they received the mineral, which could skew the results.

Ultimately, we need larger, longer, and higher-quality studies in this area.

May benefit blood sugar management

Magnesium plays a crucial role in insulin and glucose metabolism. Many people with type 2 diabetes — a condition impacting blood sugar — also have a magnesium deficiency (2).

In part, that’s because high blood sugar or insulin levels can increase the amount of this nutrient that you lose through your urine (16).

It’s been suggested that taking magnesium supplements may improve insulin resistance, a metabolic issue in which your cells don’t respond properly to insulin.

Insulin is an important hormone that helps regulate your blood sugar levels. Thus, improving insulin resistance can promote better blood sugar management, especially in people with diabetes.

In a review of 25 studies, people with or at risk for type 2 diabetes who took 250–600 mg of magnesium per day for up to 24 weeks experienced significant reductions in fasting and postmeal blood sugar levels compared with the placebo group (17).

Another review found that taking magnesium supplements for more than 4 months had a beneficial effect on insulin sensitivity and blood sugar management (18).

Though more research is needed, magnesium supplements seem to be effective at helping to stabilize blood sugar in people with type 2 diabetes (16).

May reduce heart disease risk

Low levels of magnesium have been linked to an increased risk of heart disease (19, 20).

That may be because low levels of this mineral negatively affect heart disease risk factors such as blood sugar and blood pressure (20).

A recent review of 28 studies found that magnesium supplements positively affected some heart disease risk factors in people with type 2 diabetes by lowering blood pressure, cholesterol levels, and fasting blood sugar (21).

Therefore, taking magnesium supplements may help reduce heart disease risk factors, especially in people who have a deficiency (22).

While these results are promising, more studies in this area are needed.

May improve migraine

Low levels of magnesium have been linked to migraine, a condition characterized by intense, recurring headaches (2).

A 12-week study found that people with migraine who took a daily supplement containing 600 mg of magnesium experienced 42% fewer migraine attacks, and the attacks were less intense (23).

Another review of 5 studies showed that treating migraine with 600 mg of magnesium — a high dose — was safe and effective (24).

Still, more studies are needed before firm dosage recommendations can be made for treating migraine.

Summary

Taking magnesium supplements may improve a number of health markers, such as blood pressure and blood sugar. It may also reduce your risk of health conditions such as heart disease, migraine, and depression.

Though magnesium supplements are generally considered safe, you should check with a healthcare professional before taking them, especially if you have a medical condition.

The mineral supplement may be unsafe for people who take certain diuretics, heart medications, or antibiotics (1).

Most people who take magnesium supplements don’t experience side effects, but magnesium can cause gut-related issues such as diarrhea, nausea, and vomiting, especially when used in large doses (2).

It’s important to note that people with kidney issues are at a higher risk of experiencing adverse effects related to magnesium supplements (25).

Additionally, there’s no evidence that supplementing magnesium supports health in people who don’t have a deficiency. So if you’re not experiencing any effects of magnesium deficiency, or if you know you don’t have one, you probably don’t need to take a supplement.

Always speak with a healthcare professional before starting or stopping any supplements.

Summary

Magnesium supplements are generally considered safe. However, you should speak with a healthcare professional before taking these supplements if you have a health condition or are taking any medications.

A diet high in magnesium includes healthy whole foods such as whole grains, nuts, seeds, and legumes.

Though it’s possible to get the daily recommended amount of the mineral — 400–420 mg for men and 320–360 mg for women — through diet alone, many modern diets are low in magnesium-rich foods (1).

If you can’t get enough magnesium through your diet and if it’s safe for you to do so, you may want to take a supplement.

How much should you take?

Recommended doses of magnesium supplements are 200–400 mg per day, depending on the brand.

That means that a supplement can provide you with 100% or more of the Reference Daily Intake (RDI).

The Food and Nutrition Board of the Institute of Medicine in the United States has set a tolerable upper limit of 350 mg per day for supplemental magnesium. Below this level, you are unlikely to experience any digestive side effects (1, 25).

If you have a deficiency, you may need a higher dose, but you should check with a healthcare professional before taking large doses of magnesium that exceed the RDI.

Which type should you choose?

Magnesium supplements come in a variety of forms, some of which your body can absorb more easily than others.

Types of this mineral that are better absorbed include (25, 26):

  • magnesium citrate
  • magnesium lactate
  • magnesium aspartate
  • magnesium chloride
  • magnesium malate
  • magnesium taurate

However, other factors — such as your genes and whether you have a deficiency — may also influence absorption (2).

Additionally, while many studies show that certain types of magnesium supplements are more absorbable than others, some studies find no difference between the various formulations (27).

Supplements are available in a variety of delivery systems, such as pills, gummies, powders, and liquids.

The delivery system doesn’t make much of a difference in terms of absorption — assuming you choose a form that’s well-absorbed, such as magnesium citrate — so choose one that you prefer.

Also, when shopping for a supplement, choose brands with a U.S. Pharmacopeia (USP) seal, which indicates that the supplement has been tested for potency and contaminants.

Summary

The tolerable upper limit for supplemental magnesium is 350 mg per day. Your body may absorb some forms of magnesium better than others.

The mineral magnesium is essential for keeping your body functioning at its best. Adequate magnesium intake has been linked to a reduced risk of heart disease, type 2 diabetes, and other conditions.

Dietary sources of magnesium include nuts, leafy greens, legumes, and seeds.

Taking a supplement can help you meet your daily needs if you don’t get enough of this important nutrient from food alone. Side effects are unlikely at doses below 350 mg per day.

If you’re interested in trying a supplement, choose a product that contains a form of magnesium that’s well-absorbed, such as magnesium citrate, and that has been tested by a third party such as USP.

Magnesium supplements are widely available in stores and online.

Just one thing

Try this today: Most people have suboptimal magnesium levels or are at risk of developing a deficiency. Supplementing with magnesium is a relatively inexpensive, safe, and effective way to ensure adequate magnesium levels.

Talk with a healthcare professional about taking a magnesium supplement if you would like to try one.