If you’ve ever searched for a better night’s sleep or something mild to help you unwind after a rough day, you’ve probably heard of magnesium glycinate.
It’s become a familiar presence in bedtime routines, supplement aisles and social media posts that promise everything from calmer nerves to fewer muscle cramps.
But experts say supplementing it won't automatically improve your health − “though it can be useful for people who aren't getting enough magnesium from food or who have a confirmed or suspected deficiency,” says Jen Messer, a researcher, registered dietitian and former president of the New Hampshire Academy of Nutrition and Dietetics.
The key, she says, is understanding what the supplement can do, whether you actually need it and how to
take it safely. Here’s what to know.
What is magnesium glycinate?
Magnesium glycinate − also called magnesium bisglycinate − is a supplement available in pill, powder or liquid form, explains Messer. It combines the essential mineral magnesium with glycine, which is an amino acid the body makes and uses to build proteins.
Other forms pair magnesium with different substances, such as magnesium citrate being a salt of citric acid, while magnesium oxide combines magnesium with oxygen.
“But magnesium glycinate is generally well-absorbed and tends to be easier on the digestive system than these other forms, which is one reason it is often chosen for people who experience stomach issues with other magnesium supplements,” says Amy Goodson, a registered dietitian who founded The Sports Nutrition Playbook.
As for where it exists naturally, Goodson explains that “magnesium glycinate itself does not naturally exist in foods,” and is a manufactured supplement rather than something the body produces. “But dietary magnesium is abundant in green leafy vegetables, nuts, seeds, legumes, whole grains and some fish,” Messer adds.
While magnesium is widely available in these and other sources, not everyone gets enough. For example, a New England Journal of Medicine review estimates that hypomagnesemia − low magnesium levels in the blood − affects roughly 3% to 10% of the general population. “But this is more common in certain groups,” says Messer, including people with type 2 diabetes; those taking medications like proton-pump inhibitors, some diuretics and some chemotherapy drugs; and people with alcohol dependence, chronic diarrhea or disorders that interfere with nutrient absorption.
Deficiency can cause symptoms such as muscle cramps, fatigue or weakness, but those "are not specific to magnesium, so someone who suspects a deficiency should discuss their diet and medications with a health care provider rather than self-diagnosing,” Goodson says.
What does magnesium glycinate good do?
Though “magnesium glycinate specifically has been studied far less extensively than magnesium overall,” Goodson says, magnesium is an essential nutrient because it supports “normal muscle and nerve function, blood-pressure, blood-glucose regulation and energy production.” Thus, correcting a shortage helps those processes function normally, Messer says, though taking extra won't improve them when you’re already getting enough.
And while magnesium is often associated with “improving sleep or helping people fall asleep a little faster,” Messer says, “the evidence is limited.”
Stress and anxiety findings are similarly preliminary, though Goodson says supplementation “may modestly improve anxiety symptoms in some people,” particularly when their magnesium intake or status is low.
Supplemental magnesium − not magnesium glycinate specifically − “may also reduce migraine frequency in some people,” says Messer, though the U.S. National Institutes of Health (NIH) cautions that magnesium supplementation for migraine prevention should be medically supervised.
Is magnesium glycinate safe to take?
Magnesium glycinate is generally well tolerated, but dose, kidney health and medications affect its safety and how well the body absorbs and clears it.
Magnesium supplements are gentler on digestion, but that doesn’t make glycinate free of side effects. In fact, “its most common side effects are still GI-related,” Messer says. These include diarrhea, nausea and abdominal cramping, especially at higher doses.
“Excess magnesium can also become dangerous in people with impaired kidney function,” Goodson says. When the kidneys cannot remove enough magnesium, it can accumulate, potentially causing low blood pressure, abnormal heart rhythms and other complications.
Messer also warns about interactions with certain antibiotics and osteoporosis medications because magnesium can reduce their absorption, "though a pharmacist can advise whether doses need to be spaced apart and by how much."
For dosing, non-pregnant adult women generally need 310–320 milligrams daily and men need 400–420 milligrams, depending on age, according to the NIH. But these are total daily requirements, including the magnesium you get from food, not recommended supplement doses. Goodson recommends checking “the amount of elemental magnesium on the Supplement Facts panel” of any magnesium supplements you take. But keep in mind that this measures magnesium itself rather than the weight of the entire magnesium-glycine compound.
Because symptomatic deficiency is uncommon in otherwise healthy people and many purported benefits remain uncertain, supplementation isn’t commonly recommended.
“Typically, the only time it makes sense to take a micronutrient supplement, including magnesium glycinate,” Messer says, “is when you have a confirmed deficiency or a specific reason for why you may not be meeting your needs.”
This article originally appeared on USA TODAY: What is magnesium glycinate good for? Benefits and risks, explained
