How does magnesium help with sleep?

The role magnesium plays in supporting optimal sleep is not fully understood. One possible explanation is that magnesium is a stimulator of GABA , a naturally occurring amino acid that works as a neurotransmitter. GABA is known to decrease activity in the nervous system, which can lead to relaxation. Some studies show that getting enough magnesium (from either food or supplements) may help with sleep quality and duration. While there is some evidence that magnesium supplements specifically may help with sleep, more research is needed.

Does magnesium make you poop?

Some forms of magnesium can have a laxative effect by drawing water into the gastrointestinal tract, stimulating gastric motility, which may help alleviate constipation. Magnesium citrate is one of the more widely known forms used to treat constipation, and Dr. Ming Yeh uses magnesium citrate most often for constipation. Most often, dependent upon the magnesium citrate dose, the bowel movement will occur 30 minutes to four hours after ingesting the supplement.

Does magnesium lower blood pressure?

Magnesium, along with other electrolytes, plays an important role in blood pressure regulation . While some research studies have found magnesium supplementation to lower blood pressure, more research is needed. In 2022, the FDA approved a health claim stating, “Consuming diets with adequate magnesium may reduce the risk of high blood pressure (hypertension). However, the FDA has concluded that the evidence is inconsistent and inconclusive.” More research is needed in this area before we can fully understand the effects of magnesium supplementation on the prevention of and treatment of cardiovascular disease, including hypertension. To manage and prevent high blood pressure, the American Heart Association recommends consuming a well-balanced, nutrient-dense diet that is low in sodium as well as maintaining a healthy weight, managing stress, engaging in regular physical activity, and reducing high-risk lifestyle behaviors like smoking and drinking.

The 9 Best Magnesium Supplements of 2024

Composite for best magnesium supplements — Verywell Health / Alexander Huang

Magnesium has been getting a lot of buzz, and the hype is warranted: Nearly half of Americans may not get enough magnesium from their diet. Magnesium is an essential mineral for regulating blood sugar, blood pressure, muscle function, bone health, nerve messaging, and protein production. While there are many magnesium-rich foods, such as seeds, nuts, spinach, whole grains, yogurt, and legumes, a supplement may be helpful to meet your magnesium needs.

A magnesium supplement may be especially helpful if you have a health condition, such as diabetes or certain gastrointestinal disorders that cause constipation, if you're pregnant or breastfeeding, or if you're an older adult. These groups of people might have more trouble absorbing magnesium, or have higher magnesium needs. A healthcare professional can also help determine if you are low in magnesium and if a supplement is needed.

To get our best magnesium supplements, we researched many different brands and forms of magnesium and prioritized supplements that are third-party tested and contain research-backed forms of magnesium in appropriate dosages.

Editor’s Note

Our team of registered dietitians reviews and evaluates every single supplement we recommend according to our dietary supplement methodology. From there, a registered dietitian on our Medical Expert Board reviews each article for scientific accuracy.

Always speak with a healthcare professional before adding a supplement to your routine to ensure that the supplement is appropriate for your individual needs and which dosage to take.

Forms of Magnesium We Recommend

Before you take a magnesium supplement, it’s important to know what form and dosage is best suited for your needs. While all forms of magnesium supplements will help increase your level of magnesium, they each have different benefits, absorbability, and effects on the body. For example, Ella Soderholm, RN, MNT, recommends different forms of magnesium depending on her client’s needs, from stress management to constipation relief.

For our top picks, we chose bioavailable forms of magnesium (meaning the body can absorb and utilize them). Here are some of the options you'll see, along with some of the conditions they're helpful for. That said, several different kinds of magnesium might be helpful for a given condition—we've explained more in each product review, but you can always speak to a healthcare provider if you're not sure which one is right for you.

Magnesium glycinate: Well tolerated at high doses, magnesium glycinate has the amino acid glycine attached to magnesium, which may enhance the quality of sleep. In this form, the magnesium is bound to glycine to form chelated magnesium, which is absorbed better than other forms of magnesium.
Magnesium citrate: Magnesium citrate pulls water from the body into the gastrointestinal tract, which can increase gut motility, creating a laxative effect. This form may be a good option for alleviating constipation.
Magnesium L-threonate: This form of magnesium can pass the blood-brain barrier, meaning it may have brain health benefits.
Magnesium malate: This form of magnesium may have benefits for muscle function, repair, and support.
Magnesium oxide: Magnesium oxide is not as well absorbed as other forms, but some research shows it may be helpful in the prevention and management of headaches and migraines.

Magnesium taurate (also called magnesium taurinate) and magnesium aspartate also appear in the supplements we recommend below; both of them are well-absorbed forms. Magnesium chloride is another generally available form, though it may cause stomach upset for some people, especially in high doses.

Chelated Magnesium

You may see the term "chelated magnesium" on supplements. It simply means the magnesium is bound to another substance, like glycine in magnesium glycinate. Chelated magnesium is considered to have a higher absorption rate because it can bypass the usual way magnesium gets absorbed.

Our Top Picks

Best Overall:

Pure Encapsulations Magnesium (Glycinate) at Amazon ($45)

Jump to Review

Best Powder:

Thorne Research Magnesium Bisglycinate Powder at Amazon ($48)

Jump to Review

Best Liquid:

NutriCology Magnesium Chloride Liquid at Amazon ($22)

Jump to Review

Best for Constipation:

Pure Encapsulations Magnesium at Amazon ($20)

Jump to Review

Best for Muscle Support:

Thorne Magnesium CitraMate at Amazon ($19)

Jump to Review

Best for Bone Health:

Nature Made Magnesium Capsules with Vitamin D and Zinc at Amazon ($18)

Jump to Review

Best for Cognitive Support:

Metagenics Mag L-Threonate at Amazon ($80)

Jump to Review

Best Magnesium Complex:

Nordic Naturals Magnesium Complex at Amazon (See Price)

Jump to Review

Best Gummy:

Trace Minerals Magnesium Gummies at Amazon ($22)

Jump to Review

Best For Pregnancy:

NATALIST Magnesium Plus 300 mg at Amazon ($34)

Jump to Review

In This Article

Forms of Magnesium We Recommend
Our Picks
Where We Stand
Who Should Take It
How We Selected
How Much to Take
Our Experts
FAQ
Who We Are

Best Overall

Pure Encapsulations Magnesium (Glycinate)

Amazon

View On Amazon $45 View On Walmart $45 View On Pureformulas.com

Pros

Well-tolerated form
Gluten-free, vegan, non-GMO, and free of major allergens
Third-party tested

Cons

Some may need up to four capsules per day

Key Specs

Supplement Type: Capsule | Magnesium Form: Magnesium glycinate | Serving Size: 1-4 per day | Magnesium per Capsule: 120 mg | Servings per Container: 3 size options (90, 180, 360)

Why We Recommend It

Pure Encapsulations Magnesium earns the top spot on our list because it is from a trusted, third-party-tested brand and contains a preferable form of magnesium. Most people are able to dose at higher amounts with minimal gastrointestinal distress and other side effects when compared to other forms of magnesium, making magnesium glycinate the preferred type for correcting deficiencies.

Pure Encapsulations tests all raw materials for identity, potency, contaminants, and heavy metals. They utilize third-party laboratories and are NSF-registered as a facility. In addition to the rigorous testing, this magnesium glycinate is certified gluten-free, non-GMO, and vegan. Each capsule contains 120 milligrams of magnesium, providing nearly one-third of the RDA for magnesium for most adults.

Things to Consider

While we like the flexibility of the dosing depending on your needs, those looking to correct a magnesium deficiency may need to take multiple servings per day.

Verywell Health / Alexander Huang
Verywell Health / Alexander Huang

Best Powder

Thorne Research Magnesium Bisglycinate Powder

Walmart

View On Amazon $48 View On Walmart $48 View On IHerb $48

Pros

NSF Certified for Sport
200 milligrams in a single scoop
Well-tolerated form

Cons

Some may not like the taste of monk fruit sweetener

Key Specs

Supplement Type: Powder | Magnesium Form: Magnesium glycinate | Servings Size: 1 scoop (3 grams) | Magnesium per Serving: 200 mg | Servings per Container: 60

Why We Recommend It

Magnesium Bisglycinate from Thorne is in the magnesium glycinate form we love, but in a powder version that you can easily mix with water or any other liquid. As we mention above, magnesium glycinate is a well-tolerated and highly absorbable form of magnesium.

Thorne’s Magnesium Bisglycinate contains 200 milligrams per serving and is free of major allergens, including gluten, dairy, and soy. It is sweetened with monk fruit, a non-nutritive sugar substitute. This product is third-party tested and NSF Certified for Sport, making it a great choice for athletes in need of a magnesium supplement because it is tested for banned substances for athletic competitions.

Things to Consider

This powder contains the sweetener monk fruit, which can have a very sweet taste that some people may dislike.

Verywell Health / Alexander Huang
Verywell Health / Alexander Huang
Verywell Health / Alexander Huang

Best Liquid

NutriCology Magnesium Chloride Liquid

Amazon

View On Amazon $22 View On IHerb View On Nutricology.com

Pros

Third-party tested
Can add to any beverage
Recommended dose unlikely to cause digestive side effects

Cons

Metallic taste
Recommended dosing of 2-3 times daily

Key Specs

Supplement Type: Liquid | Magnesium Form: Magnesium chloride | Servings Size: ½ teaspoon | Magnesium per Serving: 66.5 mg | Servings per Container: 94

Why We Recommend It

If you prefer liquid supplements instead of swallowing a pill, try NutriCology’s Magnesium Chloride Liquid, an easily absorbable form of magnesium. Take note that this pick contains lower amounts of magnesium per serving than some of the other picks on our list, providing only 16% of the daily value in 1/2 teaspoon, which means you might need to take it in multiple doses. This product is third-party tested and is manufactured in an NSF-registered facility, making it a quality choice.

Things to Consider

This supplement can have a metallic taste, so we recommend mixing it into a flavored beverage to make it more palatable.
The recommended dosage is 2-3 times per day, depending on your needs.

Verywell Health / Alexander Huang
Verywell Health / Alexander Huang

Best for Constipation

Pure Encapsulations Magnesium

Amazon

View On Amazon $20 View On Walmart $20 View On Pureformulas.com

Pros

Third-party tested
Certified gluten-free, vegan, and non-GMO
Form is shown to alleviate occasional constipation

Cons

May cause cramping and diarrhea for some

Key Specs

Supplement Type: Capsule | Magnesium Form: Magnesium citrate | Servings Size: 1-4 per day | Magnesium per Capsule: 150 mg | Servings per Container: 2 size options (90, 180)

Why We Recommend It

We like that these capsules have magnesium citrate—a well-absorbed form and a good choice for treating constipation. Magnesium citrate helps constipation by increasing gut motility, creating a laxative effect. Keep in mind this supplement should be used for occasional constipation relief. Be sure to consult a healthcare provider for chronic constipation, as it may lead to dehydration and an imbalance of key electrolytes if used long-term.

Pure Encapsulations tests all raw materials for identity, potency, contaminants, and heavy metals utilizing third-party laboratories in addition to being an NSF-registered facility. This magnesium citrate is certified gluten-free, non-GMO, and vegan. At 150 milligrams per capsule, Pure Encapsulations Magnesium Citrate can be a good option to treat a magnesium deficiency or constipation when directed by a healthcare professional.

Things to Consider

Potential side effects of magnesium citrate include cramping, gas, and diarrhea. Be sure to address any of these issues with a healthcare provider.

Best for Muscle Support

Thorne Magnesium CitraMate

Amazon

View On Amazon $19 View On Thorne.com $18

Pros

Blend of magnesium citrate and malate
Free of common allergens, including gluten, tree nuts and dairy

Cons

May cause gastrointestinal symptoms for some

Key Specs

Supplement Type: Capsule | Magnesium Form: Citrate and malate | Servings Size: 1-3 daily | Magnesium per Capsule: 135 mg | Servings per Container: 30-90

Why We Recommend It

Muscles use magnesium to contract and make new proteins and for energy metabolism. Therefore, people who are physically active may have higher magnesium needs. While more research is needed, some studies have found that magnesium supplementation may improve aerobic and anaerobic exercise performance.

We like that Thorne combines two highly bioavailable forms of magnesium in one capsule. This supplement contains 135 milligrams of magnesium per capsule, with 55 milligrams coming from magnesium citrate and 80 milligrams from magnesium malate. The malate form of magnesium means it is bound to malic acid, which may also have a beneficial role in muscle recovery. Thorne’s Magnesium CitraMate is free of major allergens, including gluten, dairy, and soy. Thorne is a well-trusted supplement brand that partners with top athletic teams and designs supplements to aid in muscle recovery and repair for athletes.

Things to Consider

Magnesium citrate may cause gastrointestinal side effects in some, including cramping and diarrhea.

Best for Bone Health

Nature Made Magnesium Capsules with Vitamin D and Zinc

Amazon

View On Amazon $18 View On Naturemade.com View On Instacart.com

Pros

Contains a combination of magnesium forms plus vitamin D, and zinc
Trusted brand
Two capsules dose can be tailored to your needs

Cons

Not all may need the higher dose of vitamin D and zinc, especially if you take other supplements
Not clearly third-party tested, but brand is reputable

Key Specs

Supplement Type: Capsule | Magnesium Form: Magnesium Oxide, Citrate, Glycinate, and Malate | Servings Size: 2 | Magnesium per Capsule: 115 mg | Servings per Container: 30

Why We Recommend It

Nature Made Magnesium Capsules with Vitamin D and Zinc is our top pick if you’re looking for a magnesium supplement to support bone health. Magnesium is involved in helping build new bone cells. It’s also needed to help regulate the parathyroid hormone, which regulates calcium levels. Some research shows that having a higher intake of magnesium may increase bone density, especially in post-menopausal women.

While there isn’t a specific form of magnesium best for bone health, we like that Nature Made combines four forms of magnesium to provide 55% Daily Value (DV) and 150% Daily Value (DV) for vitamin D per two-capsule serving. Magnesium and vitamin D work together to support bone health. Magnesium helps convert vitamin D to its active form, and vitamin D is needed to absorb calcium.

Zinc contributes to bone health, immune function and doesn’t compete with magnesium for absorption. The two-capsule serving provides 95% Daily Value of zinc. If you don’t want or need this much zinc or vitamin D in this supplement, you could take just one capsule per day. A healthcare professional can give individual guidance for your specific needs for these nutrients.

We like that this bone-focused magnesium supplement does not contain calcium, as high amounts of supplemental magnesium and calcium compete for absorption. If it’s recommended for you to take a calcium and magnesium supplement, it can be helpful to take them at different times.

Things to Consider

While this specific supplement isn’t third-party tested, Nature Made is a trusted brand and has many products with strong third-party testing

Best for Cognitive Support

Metagenics Mag L-Threonate

Amazon

View On Amazon $80 View On Metagenics.com

Pros

Transparent ingredient testing
Non-GMO, gluten-free, and vegetarian
Form of magnesium can get past the blood-brain barrier

Cons

More stringent dosing and timing is recommended

Key Specs

Supplement Type: Capsule | Magnesium Form: Magnesium L-threonate | Servings Size: 2-3 | Magnesium per Capsule: 49 mg | Servings per Container: 40-60

Why We Recommend It

Metagenics Mag L-Threonate has magnesium in the L-threonate form. This form is a patented combination of magnesium, a compound of vitamin C, and threonic acid. This unique combination provides a magnesium form that has a higher ability to cross the blood-brain barrier. While research is limited, some studies suggest there are potential cognitive health benefits associated with magnesium L-threonate. This form of magnesium may also help with improving sleep.

Metagenics products are made in an NSF-registered facility, and all their supplements have strong in-house testing for purity. Metagenics has full transparency—you can enter the lot number for each batch of supplements to see the test results. Additionally, their products are gluten-free, non-GMO, and made without artificial sweeteners.

Things to Consider

It is recommended to take one capsule in the morning and two capsules in the evening, two hours before bedtime.

Best Magnesium Complex

Nordic Naturals Magnesium Complex

Amazon

View On Amazon View On Walmart $19

Pros

Three forms of highly absorbable magnesium
Third-party tested
Low risk for digestive upset

Cons

Recommended dosage of three capsules per day
Some may need to take more than the recommended dose

Key Specs

Supplement Type: Capsule | Magnesium Form: Magnesium glycinate, aspartate complex, and taurinate complex | Servings Size: 3 capsules | Magnesium per Capsule: 75 mg | Servings per Container: 30

Why We Recommend It

Nordic Naturals Magnesium Complex has a blend of three highly absorbable forms of magnesium—magnesium glycinate, aspartate, and taurinate. Taking a blend of forms of magnesium can help increase absorption, and we like that this complex only has forms of magnesium that minimize the risk of digestive discomfort. Each three-capsule serving provides 225 milligrams of magnesium, which is 54% Daily Value.

These capsules are third-party tested for ingredient purity and are certified vegan and non-GMO.

Things to Consider

If you are magnesium deficient, you may need a higher dose than the three-capsule serving.

Best Gummy

Trace Minerals Magnesium Gummies

Amazon

View On Amazon $22 View On Traceminerals.com

Pros

Certified vegan
No artificial colors or sweeteners
Third-party tested

Cons

Lower magnesium dose per gummy

Key Specs

Supplement Type: Gummy| Magnesium Form: Magnesium citrate | Servings Size: 1 gummy | Magnesium per Gummy: 84 mg | Servings per Container: 120

Why We Recommend It

If you are looking for a chewable magnesium supplement, try Trace Minerals Magnesium Gummies. We like that these gummies are third-party tested for purity and potency. These gummies are gluten-free and use agar instead of gelatin, making them certified vegan, kosher, and halal. The pink color comes from organic black carrots, and no artificial colors or sweeteners are added.

One gummy provides 84 milligrams (20% DV) of magnesium citrate, the form of magnesium that can have a laxative effect. These gummies also contain inulin, which can act as a prebiotic to help support gut health.

While gummies can be an appealing supplement option for kids, remember to check with a healthcare professional before giving a child a magnesium gummy (or any other supplement). If you want another flavor other than watermelon, these gummies also come in peach and tangerine flavors.

Things to Consider

This is a lower-dose magnesium supplement, so it may not be suitable for those trying to correct a magnesium deficiency.

Best For Pregnancy

NATALIST Magnesium Plus 300 mg

Amazon

View On Amazon $34 View On Natalist.com

Pros

Internal testing for ingredient purity
A research-backed formulation developed by OBGYNs and Registered Dietitians
Contains vitamin D3 and calcium

Cons

Some may not like the taste of stevia

Key Specs

Supplement Type: Powder | Magnesium Form: Magnesium gluconate | Servings Size: 1 scoop (9 grams) | Magnesium per scoop: 300 mg | Servings per Container: 15

Why We Recommend It

During pregnancy, magnesium needs increase up to 350–400 milligrams per day, depending on age. While some prenatal vitamins contain magnesium, it may not be enough to meet your needs. Therefore, an added magnesium supplement during pregnancy may be needed.

We like Natalist Magnesium Plus because it's a researched-backed formulation containing nutrients needed for bone health. This supplement contains 300 milligrams of magnesium in the form of magnesium gluconate, which is highly bioavailable and typically well tolerated. It also has 125% DV for vitamin D and 15% DV for calcium. It comes in a raspberry-flavored and stevia-sweetened powdered form that you mix with water.

Quality and safety are particularly important when choosing a supplement to take during pregnancy. We appreciate that Natalist is a company focused on supplements for the specific needs of women’s stages of fertility, pregnancy, and postpartum, with science-backed formulations developed by OBGYNs and Registered Dietitians. They have strong in-house testing for purity and potency, but it is important to note that they do not participate in certified third-party testing.

Things to Consider

If you are taking any other supplements, including a prenatal vitamin, make sure you are not exceeding the Tolerable Upper Intake Level (UL) for vitamin D3, magnesium, or calcium. Note that the UL for magnesium from supplements is 350 milligrams for adults, and this magnesium supplement has 300 milligrams. You could adjust the dosage, using half a scoop for example, depending on your needs.

Where We Stand

Pure Encapsulations Magnesium (Glycinate) is our top pick because it's a well-tolerated form of magnesium, it's third-party tested, and it has easily adjustable dosing to meet your individual needs. If you prefer a powdered form, try Thorne Magnesium Bisglycinate powder, and for constipation relief, try Pure Encapsulations Magnesium (Citrate).

Who Should Or Shouldn’t Take a Magnesium Supplement?

If you are magnesium deficient or have a health condition that puts you at risk for deficiency, a magnesium supplement may be beneficial. For healthy adults, the body is able to excrete excess magnesium from food. However, too much magnesium from supplements can lead to negative side effects like cramping and diarrhea. People with impaired kidney function, infants and children, and people taking certain medications may have other harmful effects from getting too much magnesium from supplements.

Those who may benefit from a magnesium supplement include:

People who eat a limited diet: People who don’t eat a lot of magnesium-rich foods like seeds, nuts, spinach, whole grains, yogurt, and legumes may be at higher risk for deficiency.
People with gastrointestinal issues: People with gastrointestinal diseases such as celiac disease, Crohn’s disease, Ulcerative colitis, and irritable bowel syndrome (IBS) may have difficulty absorbing magnesium. So in these cases, magnesium supplementation may be needed. Additionally, magnesium citrate specifically may help to prevent and alleviate constipation, a common symptom of certain gastrointestinal diseases. Ella Soderholm, RN, MNT, says she primarily uses magnesium "for the beneficial effects it has on gut health, aiding in peristalsis, helping move food through your intestines and prevent[ing] constipation.”
People who suffer from migraines: While it is still a new area of research, it has been found that people who suffer from migraine headaches may have a lower level of magnesium in their blood and tissues when compared to those who do not suffer from migraines. The American Academy of Neurology and the American Headache Society now provide evidence-based guidelines stating that magnesium therapy may be effective for migraine prevention under the supervision of a healthcare provider. “Magnesium, in particular magnesium oxide, has also been studied in migraine headaches as an effective preventative [supplement],” states Ann Ming Yeh, MD.
People who are pregnant or breastfeeding: During pregnancy and lactation, magnesium needs increase to support the pregnant person and the growing baby. If a new or pregnant parent is not meeting their magnesium needs from diet and a prenatal vitamin, it may be beneficial to speak to a healthcare provider about adding a magnesium supplement.
People with diabetes: Magnesium plays an important role in how the body regulates blood sugar, so a magnesium deficiency can enhance insulin resistance in those with type 2 diabetes. Additionally, increased urinary frequency from chronically high blood sugar can result in increased losses of electrolytes, including magnesium. Some studies have shown that supplementing with magnesium may improve diabetes-related health measures; however, more research is needed. Be sure to speak to a healthcare provider to determine if a supplement may benefit you.
Older adults: As we get older, appetite and food intake can naturally go down. If an older adult is not eating magnesium-rich foods, their risk of magnesium deficiency is greater. Secondly, as we age, our bodies' ability to properly and efficiently absorb all nutrients decreases. There are also certain medications older adults take that may alter magnesium levels, increasing the risk for magnesium deficiency.

How We Selected Best Magnesium Supplements

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here.

We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products.

It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

Third-Party Testing

Supplements that are third-party tested are sent to a lab where they are tested for purity and potency to ensure they contain what they say they contain and do not contain any potential contaminants. Trusted third-party certifications include ConsumerLab.com, NSF, USP, and Informed Choice. However, these certifications can be difficult to obtain and expensive for manufacturers, so many companies choose not to get their products tested. If you are selecting a supplement that does not have third-party testing, we recommend choosing a trusted brand that does rigorous internal testing.

Ingredients and Potential Interactions

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

There are several medications that can potentially interact with magnesium supplements and affect your overall magnesium status. If you are taking any of the below medications, be sure to speak to a healthcare provider about your magnesium intake.

Diuretics: If you are on chronic treatment with diuretics such as Lasix, Bumex, Aquazide H, Edecrin, or Aldactone, be sure to speak to a healthcare provider regarding your magnesium status. Certain diuretics can lead to an increased loss of magnesium, while others may cause you to retain magnesium and not excrete it properly.
Proton pump inhibitors (PPI): Healthcare providers should measure the serum magnesium level in any patient on long-term PPI treatment, as PPIs have been known to cause low levels of serum magnesium.
Antibiotics: Magnesium has the potential to bind to certain antibiotics, making them work less effectively. It is advised to take some antibiotics at least two hours before or four to six hours after a supplement containing magnesium.
Bisphosphonates to treat osteoporosis: When taking oral bisphosphonates to treat osteoporosis, it is important to separate that dose from any magnesium-containing supplements by at least two hours, as the magnesium has the potential to reduce total absorption of the medication.

How Much to Take

The current Recommended Daily Allowances (RDA) for magnesium from both food and supplements for adults are below listed by age and gender.

19–30 years: 400 milligrams (males), 310 milligrams (females), 350 milligrams (pregnancy), 310 milligrams (lactation)
31–50 years: 420 milligrams (males), 320 milligrams (females), 360 milligrams (pregnancy), 320 milligrams (lactation)
51+ years: 420 milligrams (males), 320 milligrams (females)

Magnesium has a Tolerable Upper Intake Level (UL), meaning you can take too much from a supplement. Exceeding the UL of magnesium from supplements can result in gastrointestinal distress, such as diarrhea, nausea, and cramping. Other symptoms of magnesium toxicity can include low blood pressure, vomiting, muscle weakness, irregular heartbeat, and cardiac arrest.

It is important to note that the ULs only refer to magnesium from supplements or medication and not from food. The following are the established Tolerable Upper Intake Levels for magnesium supplements only (not magnesium from food) based on age for both males and females:

Birth to 12 months: None established
1–3 years: 65 milligrams
4–8 years: 110 milligrams
9–18 years: 350 milligrams
19+ years: 350 milligrams

Our Experts

We rely on expert input at every phase of reporting and writing this story, from researching various forms of magnesium, to looking at specific products, to evaluating the correct form and dosage. These are some of the people we consulted in writing this story.

Ella Soderholm, RN, MNT is a Registered Nurse (RN), Master Nutrition Therapist (MNT), gut microbiome and digestive health expert, and founder of Undercurrent Wellness, LLC.
Ann Ming Yeh, MD is a Stanford-trained pediatric gastroenterologist and integrative pediatrician with over 12 years of experience in taking care of children and optimizing digestive health and wellness.
Anne Cook Carroll, MS, RD, CDN, is a Registered Dietitian who works with patients to meet their health goals and educates patients on the appropriate usage of supplements to optimize their nutritional status and overall health. She also specializes in supplement research and analysis.
Shushy Rita Setrakian, MS, RD, is a registered dietitian who is passionate about converting nutrition science into meaningful dietary recommendations. She has an eye for spotting the latest nutrition trends, research and breaking down what that can mean for your supplement and food choices.

Frequently Asked Questions

How does magnesium help with sleep?

The role magnesium plays in supporting optimal sleep is not fully understood. One possible explanation is that magnesium is a stimulator of GABA, a naturally occurring amino acid that works as a neurotransmitter. GABA is known to decrease activity in the nervous system, which can lead to relaxation.
Some studies show that getting enough magnesium (from either food or supplements) may help with sleep quality and duration. While there is some evidence that magnesium supplements specifically may help with sleep, more research is needed.
Does magnesium make you poop?

Some forms of magnesium can have a laxative effect by drawing water into the gastrointestinal tract, stimulating gastric motility, which may help alleviate constipation. Magnesium citrate is one of the more widely known forms used to treat constipation, and Dr. Ming Yeh uses magnesium citrate most often for constipation. Most often, dependent upon the magnesium citrate dose, the bowel movement will occur 30 minutes to four hours after ingesting the supplement.
Does magnesium lower blood pressure?

Magnesium, along with other electrolytes, plays an important role in blood pressure regulation. While some research studies have found magnesium supplementation to lower blood pressure, more research is needed. In 2022, the FDA approved a health claim stating, “Consuming diets with adequate magnesium may reduce the risk of high blood pressure (hypertension). However, the FDA has concluded that the evidence is inconsistent and inconclusive.” More research is needed in this area before we can fully understand the effects of magnesium supplementation on the prevention of and treatment of cardiovascular disease, including hypertension.
To manage and prevent high blood pressure, the American Heart Association recommends consuming a well-balanced, nutrient-dense diet that is low in sodium as well as maintaining a healthy weight, managing stress, engaging in regular physical activity, and reducing high-risk lifestyle behaviors like smoking and drinking.

Who We Are

Brittany Scanniello RDN runs an integrative nutrition practice in Lafayette Colorado, Eat Simply Nutrition. She is constantly looking for nutraceutical alternatives to assist her clients with their day-to-day concerns. With a background as a clinical pediatric gastrointestinal dietitian, magnesium is a supplement she works with often. She emphasizes the importance of purity, safe dosages, and a quality product above all else when recommending any form of supplementation.