Magnesium: Benefits, Uses, Side Effects, and More

Melissa Nieves, LND, RD, is a registered dietitian with Practical Nutrition, LLC. She also works as a bilingual telehealth dietitian for Vida Health Program.

Magnesium is an essential mineral that your body doesn't make, which means you have to obtain it through your diet. Magnesium is needed for critical functions such as blood sugar regulation, muscle contraction, nerve function, blood pressure maintenance, and DNA synthesis so it's important to take in optimal amounts of this nutrient on a daily basis.

Even though magnesium is found in a variety of foods, like beans, vegetables, and seeds, most people's diets are too low in magnesium, which can negatively impact health in many ways.

Taking a magnesium supplement is an easy way to increase your intake of this important mineral. Plus, magnesium supplements may benefit health in several ways, from lowering blood sugar to improving sleep quality.

Here's everything you need to know about magnesium supplements, including their potential health benefits, possible side effects, and how to use magnesium supplements safely.

Dietary supplements are minimally regulated by the FDA and may or may not be suitable for you. The effects of supplements vary from person to person and depend on many variables, including type, dosage, frequency of use, and interactions with current medications. Please speak with your healthcare provider or pharmacist before starting any supplements.

Your body needs a steady supply of magnesium in order to stay healthy and perform vital functions. Magnesium supplements can be a helpful way to increase magnesium intake for people who don't get enough magnesium through their diet.

Taking in extra magnesium through dietary supplements has also been linked to several health benefits.

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Magnesium is necessary for carbohydrate metabolism and insulin secretion, which is why maintaining optimal magnesium levels is essential for healthy blood sugar regulation.

People with prediabetes and diabetes are more likely to develop low magnesium levels due to increased urinary magnesium excretion caused by elevated blood sugar. In order to maintain optimal magnesium levels, people with diabetes may require magnesium supplements.

A 2021 review of 25 studies found that magnesium supplements significantly reduced fasting blood sugar levels and improved insulin sensitivity in people with diabetes and in those at high risk for diabetes compared to placebo treatments.

What's more, studies show that people with both type 1 and type 2 diabetes who have higher blood levels of magnesium tend to have better blood sugar control than people with lower magnesium levels.

Magnesium plays an important role in your body's stress response. If you’re not taking in enough magnesium, it can impact your ability to deal with stress. In fact, research shows that people who are frequently stressed have lower blood levels of magnesium compared to people who aren't typically stressed.

What's more, magnesium supplements may be helpful for improving symptoms of common mental health conditions like anxiety and depression.

A 2017 study in 112 people with depression found that daily supplementation with 248 milligrams of magnesium chloride for 6 weeks led to significant improvements in symptoms of depression and anxiety compared to a placebo group.

Your bones contain up to 60% of the total magnesium stored in your body. If you don't take in enough magnesium, it inhibits the activity of bone tissue-forming cells called osteoblasts while increasing the action of osteoclasts, which are cells that break down bone. Magnesium is also necessary for the absorption and metabolism of vitamin D, a nutrient that's critical for skeletal health.

People with low blood levels of magnesium are at a higher risk for developing bone disorders like osteopenia and osteoporosis. Fortunately, studies show that magnesium supplements are effective for improving bone mineral density and decreasing fracture risk.

Magnesium is necessary for proper nerve function and also helps regulate inflammation and improve blood flow in the brain. People who experience frequent headaches, like migraines, tend to have lower blood levels of magnesium.

In fact, magnesium deficiency is considered an independent risk factor for migraine headaches.

A number of studies have found that magnesium supplements are helpful for reducing the frequency and severity of symptoms in people with migraines and tension-type headaches. According to a 2022 review, magnesium supplements may be effective for reducing the frequency of migraine attacks, and reducing the cost and side effects of traditional migraine treatments like medications.

Magnesium is involved in several processes necessary for healthy blood pressure regulation. For example, magnesium promotes the release of a signaling molecule called nitric oxide. Nitric oxide helps relax blood vessels, which is important for maintaining healthy blood pressure levels.

Taking in optimal amounts of magnesium through your diet can help reduce your risk of developing high blood pressure. Studies show that taking magnesium supplements may help reduce both systolic and diastolic blood pressure in people with high blood pressure.

However, according to a 2021 review of 49 studies, people with untreated hypertension may require high supplemental doses containing at least 600 milligrams of magnesium per day in order to effectively lower blood pressure levels.

Maintaining healthy magnesium levels can help you get restful sleep. Magnesium binds to certain receptors in the central nervous stems and activates GABA, one of the main neurotransmitters responsible for sleep regulation.

Some studies show that magnesium supplements can help people fall asleep faster and stay asleep longer. A 2022 review also found that people with the highest magnesium intake, including both dietary magnesium and magnesium supplements, were the most likely to meet the National Sleep Foundation's sleep recommendations of seven to nine hours per night.

Magnesium is concentrated in a number of foods, including nuts, vegetables, seeds, and beans.

Here's some of the best dietary sources of magnesium:

The best way to ensure you’re getting plenty of magnesium on a daily basis is to follow a nutritious diet that's high in plant foods and to limit your intake of foods low in magnesium, like ultra-processed snack foods.

Magnesium can be taken any time of day, with or without food.

It's important to note that there are several forms of magnesium, so you’ll want to read the back of supplement labels to make sure you’re choosing the right kind for your health needs.

Studies show that certain forms such as magnesium citrate, magnesium glycinate, magnesium acetyl taurate, and magnesium malate are better absorbed by the body compared to other forms, like magnesium oxide and magnesium sulfate.

Currently, it's recommended that people take in between 310 and 420 milligrams of total magnesium per day, depending on age and sex. Unfortunately, more than half of Americans fall short of these intake recommendations.

What's more, experts argue that although the current daily intake recommendations are usually enough to prevent magnesium deficiency, they may not be high enough to promote optimal magnesium status. This suggests that most people would benefit from increasing their magnesium intake, which can be accomplished through increasing consumption of magnesium-rich foods or by taking a magnesium supplement.

Magnesium supplements provide varying doses of magnesium, but most pills and capsules contain around 100 to 150 milligrams of magnesium. Keep in mind that you may have to take several pills or capsules in order to meet your dosage recommendations.

Magnesium supplements are generally safe and not associated with significant side effects when used appropriately. However, it is possible to take in too much magnesium from dietary supplements, which can lead to serious complications.

People with kidney issues and elderly people with bowel conditions are more susceptible to developing high blood levels of magnesium, which is called hypermagnesemia in the medical field.

Several medications can deplete magnesium stores. Plus, magnesium supplements may reduce the absorption of some medications.

When shopping for a magnesium supplement, it's important to choose high-quality products from trusted brands. Some supplement manufacturers hire third-party labs to test their products for purity and potency, which helps improve supplement safety. Whenever possible, purchase supplements from brands certified by organizations like UL, USP, and NSF International.

Choosing a bioavailable form of magnesium, such as magnesium glycinate or magnesium citrate, can help increase your body's ability to absorb magnesium and may help reduce the risk of gastrointestinal side effects.

Lastly, magnesium supplements contain different doses, so it's a good idea to ask a trusted healthcare provider how much supplemental magnesium you should be taking before selecting a supplement.

Although magnesium supplements are relatively safe, it is possible to overdo it. For example, taking too much supplemental magnesium may cause minor side effects like diarrhea and abdominal cramps.

Taking extremely high doses of magnesium can lead to a dangerous condition called magnesium toxicity, which occurs when blood levels of magnesium exceed 1.74–2.61 mmol/L. Magnesium toxicity is rare and is usually related to accidental overdoses of magnesium-containing products like antacids and laxatives. Magnesium toxicity can cause symptoms like low blood pressure and irregular heartbeat and can be fatal.

Because it's possible to take in too much magnesium from supplements, the Food and Nutrition Board (FNB) has established a Tolerable Upper Intake Level (UL) for magnesium, which is currently set at 350 milligrams per day. A UL is the maximum daily intake of a nutrient unlikely to cause harm. Keep in mind that the UL only applies to supplemental magnesium.

Even though studies show that magnesium can safely be taken in doses higher than 350 milligrams per day, you shouldn't take more than the UL unless it's recommended by a medical professional for a specific reason.

When taken in appropriate doses, magnesium supplements aren't usually associated with many side effects.

However, high doses of magnesium can lead to a few side effects, which mainly impact the gastrointestinal system. Certain forms of magnesium, including magnesium oxide and magnesium chloride, are more likely to cause side effects than others.

Here are some of the most common side effects associated with magnesium supplements:

If you experience gastrointestinal side effects after taking a magnesium supplement, changing the form of magnesium you take or cutting back on the dose may help.

Magnesium is a mineral that plays a number of important roles in the body.

Even though magnesium is concentrated in foods like vegetables, nuts, and beans, most people don't meet the daily intake recommendations for this nutrient.

Taking a magnesium supplement can help you cover your magnesium needs and may offer several health benefits, from enhancing sleep to reducing symptoms of anxiety.

If you’re interested in taking a magnesium supplement, ask a healthcare provider like a dietitian or doctor for advice on dosing and their recommendations for high-quality magnesium supplements.

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