The 7 Best Magnesium Supplements of 2021, According to a Dietitian

Plus, which certifications and ingredients to look for

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Our Top Picks
Providing 100 milligrams of a bisglycinate blend, it supports bone health and restful sleep.
These are coated for easy swallowing and support bone and muscle health, maintaining bone mineralization.
Sourced from trusted suppliers, these are made with only premium ingredients, and guided by nutritional experts.
NOW Foods is a leader in the supplement industry and is a budget friendly choice for quality products.
The featured ingredient in this powder is a blend of magnesium glycinate and carbonate.
This is a NSF Certified for Sport product which means it is tested for compliance with label claims.
In addition to magnesium, this product includes calcium, vitamins B6, D3, and C, and an herbal muscle support blend.

Magnesium is an essential mineral and a cofactor for hundreds of enzymatic reactions in the body. This powerful mineral is involved in energy production, protein synthesis, and cellular communication. It is a necessary mineral for optimal muscle and nerve function, blood glucose control, and blood pressure regulation.

It is estimated that half of the United States population is consuming inadequate amounts of magnesium. Fortunately, magnesium is fairly easy to obtain through food as it is widely distributed in plant and animal foods such as leafy greens, legumes, nuts, seeds, and whole grains. A varied diet will usually ensure adequate magnesium intake, however, for picky eaters or those at risk for magnesium deficiency, magnesium can be obtained from supplements.

There are numerous forms of supplemental magnesium available—including magnesium oxide, magnesium sulfate, magnesium glycinate, magnesium chloride, and magnesium citrate, as well as a number of amino acid chelates like magnesium aspartate. The best type of magnesium to supplement depends on your goals and needs. For those looking to alleviate constipation, opting for magnesium oxide or citrate might be best. Magnesium glycinate or chloride might be best to support sleep and/or relaxation. As always, it is best to consult with a doctor or healthcare provider to find out what type of magnesium is best for you.

What to Look for in Magnesium Supplements


There is no one size fits all when it comes to choosing the right supplement for you. It is important to check the ingredients when shopping for a new supplement. Be mindful of potential allergens and always reach out to your health care provider if you are unsure about complementary ingredients in a product. Not all supplements are created equal.


Look for certifications from independent, third party testing companies such as, NSF International, and USP. These organizations provide quality testing and allow products that pass their tests to display a seal of quality assurance. These seals indicate the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. 


Though most of the supplements reviewed are generally recognized as safe, you may need to consult a healthcare provider if you are already taking certain medications or supplements. It is always important to remember that just because a supplement is sourced from natural ingredients, they can still be incredibly powerful. Start a new supplement with the lowest dose possible being mindful of unwanted changes and increase as tolerated. 

How We Select Supplements

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

Here, the best magnesium supplements, according to a registered dietitian.

Best Overall: Klaire Labs Magnesium Glycinate Complex

Klaire Labs Magnesium Glycinate Complex provides 100 milligrams of a bisglycinate blend to support bone health and restful sleep. In addition to overall health, magnesium bisglycinate has been shown to help relieve pregnancy induced leg cramps in pregnant women. Combining magnesium with the amino acid glycine creates a unique compound that is highly bioavailable and well tolerated.

This product is free of the following common allergens: milk and casein, eggs, fish, shellfish, tree nuts, peanuts, wheat, gluten, soybeans, and yeast. We like that it contains no artificial colors, flavors, or preservatives making it an extremely safe choice for those with the most restrictive dietary needs. This magnesium supplement is great for overall magnesium needs.

Best Budget: Nature’s Bounty Magnesium 500 mg

Magnesium supplements do not have to cost an arm and a leg. This bottle of 200 magnesium tablets is less than ten dollars and each tablet provides 500 milligrams of magnesium (119 percent of the daily recommended intake of Magnesium) as magnesium oxide. Magnesium oxide may be beneficial with decreasing the amount of headaches experienced however more research is needed to be done in order to identify the specific benefits of this type of magnesium.

These tablets are coated for easy swallowing and support bone and muscle health, maintaining bone mineralization. We like that they are free of artificial flavors and sweeteners and are also gluten-free.

Best Glycinate: Pure Encapsulations Magnesium (Glycinate)

Magnesium glycinate is a water soluble form of magnesium which might make it more easily absorbed. Unlike other forms of magnesium, glycinate is less likely to have a laxative effect which might make it a better choice for those looking for sleep, mood, cognition and/or overall health and wellbeing support. One capsule of Pure Encapsulations Magnesium Glycinate contains 120 milligrams or 29 percent of the daily recommended intake of magnesium.

Pure Encapsulations supplements are made with only premium ingredients sourced from trusted suppliers and guided by their nutritional experts. Their products are then carefully manufactured and tested to verify their potency and purity. All Pure Encapsulations products are free from many common allergens like wheat, eggs, tree nuts and peanuts, gluten, artificial colors, flavors and sweeteners, coatings and shellacs, GMOs, unnecessary binders, fillers and preservatives making them safe for most consumers.

Best Citrate: NOW Foods Magnesium Citrate 200 mg

NOW Foods is a leader in the supplement industry and is a budget-friendly choice that does not skimp on purity or quality of products. NOW’s magnesium citrate is Kosher certified, vegan, non-GMO and keto friendly. In addition to these certifications, this product is also free of wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.

Buyers can choose to take one tablet containing 200 milligrams of magnesium from magnesium citrate or follow the serving size and take two tablets for 400 milligrams of magnesium citrate. Magnesium citrate is often used for constipation and gastrointestinal distress. When taking a new supplement, especially one for its laxative effect, it is best to start with a low dose and work up to a full dose. As always, consult with a doctor or health care provider for dosing.

Best for Sleep: Natural Vitality Calm Sleep Magnesium Citrate

Natural Vitality’s Calm Sleep is our top choice for a magnesium that promotes sleep. We love the blend of sleep supporting ingredients and the brand’s commitment to quality. The featured ingredient in this powdered supplement is a blend of magnesium glycinate and carbonate. It is suspected that almost half of all American are missing the recommended daily intake of magnesium—an extremely important nutrient as it is needed for over 300 reactions in the body and helps regulate the nervous system.

In addition to calming magnesium, you get Suntheanine+, a patented form of the relaxing amino acid L-theanine); gamma-aminobutyric acid (GABA), a neurotransmitter that helps calm brain activity; and melatonin, the hormone that helps control your natural sleep-wake cycle. This product is Non-GMO verified, vegan, gluten-free and sugar-free. For occasional sleeplessness, start with 1 teaspoon (2 grams) and gradually increase to two teaspoons (4 grams) daily.

Best for Anxiety: Thorne Research Magnesium Bisglycinate Powder

More research is needed to directly link a deficiency in magnesium to anxiety levels, however, it is safe to say that adequate intake of magnesium is important for optimal production of neurotransmitters. One scoop of Thorne’s Magnesium Bisglycinate Powder provides 48 percent of the recommended daily intake of magnesium. Magnesium glycinate has less of a laxative effect than other forms and is thought to be more effective for relaxation.

Every Thorne product is made with the purest possible ingredients—without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish. As an added safety bonus, this is a NSF Certified for Sport product which means it is tested for compliance with label claims and to ensure the absence of 280 substances banned by many major athletic organizations.

Best for Muscle Cramps: Rainbow Light Magnesium Calcium+ Food Based Tablets

About 50 to 60 percent of all the magnesium in the body is found in the skeleton and the remainder is found in soft tissue, primarily in muscle. A very small study of male recreational runners who consumed a low magnesium diet found that supplementation with 500 milligrams of magnesium decreased muscle soreness. Rainbow Light’s Magnesium Calcium+ food based tablets contain over 300 milligrams of magnesium from a blend of different forms.

In addition to magnesium, this product includes calcium, vitamin B6, vitamin D3, vitamin C and an herbal muscle support blend to boost efficacy. This product is vegetarian and contains no gluten, wheat, milk, tree nuts, peanuts, soy, eggs, fish or shellfish. As an added bonus, we like that Rainbow Light’s bottles are 100 percent recycled/recyclable EcoGuard BPA-free.

Final Verdict

Klaire Labs Magnesium Glycinate Complex (view at Amazon) is our top magnesium supplement pick. Providing 100 milligrams of a bisglycinate blend to support bone health and restful sleep this product is highly bioavailable and well tolerated. Free of the top allergens as well as artificial colors, flavors, and preservatives this is an extremely safe choice for those with the most restrictive dietary needs.


What is the best time to take magnesium? 

If you are taking magnesium citrate, it may be best to take the supplement in the evening due to its laxative effect. Magnesium supplements that are geared toward sleep support or decreased anxiety might be best used when consumed in the evening as well. In general, the best time to take any supplement is whenever you are most likely to remember.

Magnesium supplements might interfere with certain medications such as levothyroxine, antibiotics and some statin drugs. Consumers that are on prescription medications should always consult with a healthcare provider or pharmacist to discuss possible contraindications.

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 an agonist 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. More research is needed to determine magnesium’s specific effect on sleep.

Why Trust Verywell Fit?

As a Registered Dietitian, Sydney Greene takes supplement recommendations seriously. Every product has been researched and vetted by her against clinical research, product reviews, and third party testing websites. These are products she would not only feel comfortable recommending to her clients but she would take them herself if needed. 

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Article Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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