Magnesium Glycinate 101: Benefits, Usage, & Side Effects

Magnesium is an essential mineral in the body. According to the NIH, it plays a role in more than 300 diverse biochemical reactions1—everything from energy production and protein synthesis to blood sugar control and blood pressure regulation. Here's what you need to know about the different forms of magnesium and how to take a magnesium supplement to support vibrant health.

Our bodies naturally contain magnesium, but factors like medication interactions, soil depletion2, and diets filled with nutrient-poor processed foods mean that some of us (especially older folks) aren't getting enough of it.

Eating a more magnesium-rich diet is a great place to start. Magnesium is present in some delicious foods like dark leafy green vegetables, legumes and nuts, wheat and other grains, and fish.

Additionally, magnesium can be utilized in other forms—including as traditional supplement capsules, Epsom salts, magnesium oil, magnesium cream, and drinkable powder—that make it easy to incorporate it into your everyday routine. This versatility means you might have a friend who takes a magnesium supplement to help her sleep, a family member who's an Epsom salt bath enthusiast, or a co-worker who swears by that powdered magnesium she drinks for post-workout muscle recovery.

Magnesium comes in many different forms—and some are more efficient than others. Oral magnesium supplements can be found as capsules, gelcaps, powders, liquids, gummies, and more, and include forms like magnesium citrate, magnesium glycinate (aka magnesium bisglycinate), magnesium malate, and magnesium oxide. (Find our favorites here.)

Magnesium sulfate can be received by injection or by IV in a clinical setting under the care of a doctor for low magnesium and other specific clinical scenarios (e.g., during pregnancy). You'll also find magnesium sulfate in the form of Epsom salts, which you can add to your bath.

You can even find magnesium in a topical form, which includes magnesium chloride "oils" and creams. But, there is some debate whether or not transdermal magnesium really works, and the science isn't entirely clear.

Of all these forms, magnesium glycinate is a favorite among integrative and functional medicine doctors and has been extensively researched in clinical studies.

Many individuals use magnesium as a sleep aid, and its ability to induce muscle relaxation and ease stress are two of the main ways it's thought to help people fall asleep faster. In a study, magnesium glycinate supplementation subjectively improved insomnia3. Research shows that magnesium can also help us stay asleep longer by reducing the stress of the nervous system and promoting a steady state of relaxation. Finally, the supplement can promote a healthy circadian rhythm, meaning it can help our bodies get into a more natural sleep cycle and wake up feeling more refreshed.

Research has shown that magnesium glycinate can help lessen daytime sleepiness and enhance memory. One study found that taking 125-300 mg of magnesium glycinate daily helped with short-term memory and IQ.

Magnesium supplementation has a beneficial impact on blood pressure4 in those who already have a magnesium deficiency. In fact, one study5 found that “after magnesium supplementation, systolic and diastolic pressures were significantly [improved].”

Maintaining a normal blood sugar level is no easy task, but magnesium might be a useful tool in doing so. Research has shown that dietary magnesium intake (aka, eating foods high in magnesium) reduces the risk of developing type 2 diabetes. This is because magnesium helps break down sugar,6 which in turn decreases insulin resistance.

When it comes to bone health, calcium tends to get most of the attention. But magnesium is involved in bone formation7 and has an influence on parathyroid hormone and vitamin D concentrations, which are also involved in bone formation. This means that having an adequate intake of magnesium is useful for supporting healthy bones.

Low levels of magnesium in the blood (aka, a magnesium deficiency8) has been linked to migraine headaches. In addition, supplementing with magnesium has been shown to benefit individuals who have migraines9.

Studies, like one double-blinded placebo-controlled trial, have shown that taking magnesium glycinate (at a dose of 250 mg per day) helps manage PMS symptoms10. According to Jolene Brighten, N.D., a naturopathic doctor, female hormone expert, and founder of Rubus Health, "Magnesium has been shown to be effective in positively helping lower prostaglandins and easing menstrual cramps. Magnesium is also necessary for estrogen detoxification, which is why it can help ease PMS."

Studies have shown that magnesium glycinate can benefit pregnancy-induced leg cramps. In one study, 80 pregnant women participated in a double‐blinded, randomized, placebo‐controlled trial by taking 300 mg of magnesium glycinate daily. The frequency of cramping, as well as the intensity of leg cramping, were reduced by 50 percent compared to the placebo group.

According to Bindiya Gandhi, M.D., an integrative medicine practitioner, "magnesium glycinate has higher bioavailability and is gentle on your stomach, unlike other forms of magnesium."

Supplemental oral magnesium—which includes forms like magnesium citrate, magnesium glycinate, magnesium malate, and magnesium oxide—is safe in the following recommended daily doses11 by the NIH:

Clearly, there are many benefits to taking magnesium, especially if you have a deficiency in this important mineral. But are there any downsides to taking magnesium or magnesium glycinate, specifically? The most common side effects of magnesium supplements12 are diarrhea, cramping, and digestive upset. This is more common in certain forms of magnesium—like magnesium oxide and magnesium citrate.

Magnesium glycinate has the fewest side effects13 and doesn't cause digestive upset when taken in a higher dose. It's thought to be a good choice for individuals with gastrointestinal issues14 over other magnesium supplements.

Magnesium citrate is one of the other most commonly recommended sources of magnesium. Magnesium citrate has a laxative effect, but in many cases that's actually a benefit since it's used specifically to treat constipation due to its ability to increase gut motility. Of all the forms of magnesium, magnesium glycinate is least likely to cause diarrhea, and experts also turn to it for the treatment of a magnesium deficiency due to its high absorbency rate. According to Dr. Brighten, "Magnesium glycinate is highly absorbable, doesn't cause diarrhea like the citrate form can, and has a calming effect."

Magnesium citrate and magnesium glycinate are more bioavailable than other common forms of magnesium like magnesium oxide. They are both great options for magnesium supplementation, depending on your specific needs, whether they be correcting a deficiency and helping with sleep and relaxation (in which case go with the glycinate form), or increasing gut motility and supporting digestion (for these go with the citrate form).

Hypermagnesemia is the name for a magnesium overdose, which is rare but more common in individuals with kidney disease because the kidneys are responsible for excreting excess magnesium15 and work to regulate magnesium balance in the body. Overdosing on magnesium can cause serious side effects16, including an irregular heartbeat, low blood pressure, confusion, slowed breathing, coma, and even a few deaths have been reported. Keep in mind that an overdose of this measure would require a person to take thousands of milligrams of magnesium daily, which is well beyond the dose in a typical magnesium supplement. 

Although it would be difficult to overdose on magnesium-rich foods or magnesium supplements, magnesium is also the primary ingredient in some prescription and over-the-counter laxatives, and severe hypermagnesemia17 has been reported to occur from taking laxatives that contain magnesium for constipation over a long-term period. Fatal hypermagnesemia can occur in those with renal problems18 when taking these laxatives because kidneys that are not fully functional are not able to effectively clear magnesium from the body. As a general rule, you should always talk to your doctor before taking a new supplement.

Magnesium can also interact with certain medications, for example, with certain types of antibiotics19. It is usually recommended to take antibiotics at least 2 hours before or 4 to 6 hours after a magnesium-containing supplements. Another group of drugs that magnesium tends to interact with is bisphosphonates that are often used to treat osteoporosis. Magnesium can interfere with how well this drug is absorbed20, so the supplement should be taken at least two hours before or after these medications."

Magnesium glycinate is one of the most absorbable forms of magnesium. For this reason, it is a great option if you are looking to reap the benefits of magnesium supplementation, like sleep support, enhanced memory, and PMS relief.