Magnesium Is Everywhere Right Now. Do You Actually Need It?

Before you buy the bottle, figure out what problem you’re trying to solve

Magnesium Metagenics Nutritional Supplements

Magnesium is having a moment.

It is being promoted for sleep, stress, muscle cramps, blood sugar, migraines, constipation, anxiety, exercise recovery and just about everything else that can go wrong with a human body.

Some of that attention is deserved. Some of it has gotten well ahead of the evidence.

Magnesium didn’t suddenly become important because wellness influencers discovered it. It has always been important. Your body requires it for hundreds of biochemical reactions, including energy production, protein synthesis, muscle and nerve function, blood glucose regulation, blood pressure regulation and normal heart rhythm.

The more useful question isn’t whether magnesium matters.

The useful question is whether you are getting enough — and what you’re hoping a supplement will accomplish.

I spent years working in preventive and functional medicine, and that is still where I start with supplements.

First, what does magnesium actually do?

Magnesium is an essential mineral. An adult body contains roughly 25 grams of it, with most stored in bone and soft tissue rather than circulating around in the blood.

Your muscles need it. Your nerves need it. Your bones need it. Your cells use it in producing energy, making proteins and regulating the movement of other minerals across cell membranes.

This isn’t alternative medicine. It is basic physiology.

Adult women generally need about 310–320 mg of magnesium a day, while adult men generally need about 400–420 mg, depending on age. Those numbers refer to magnesium from all sources, not simply what you swallow in a supplement.

And there is an important distinction between not eating an optimal amount of magnesium and having an actual clinical magnesium deficiency.

Those are not the same thing.

Are we all magnesium deficient?

No. That claim gets tossed around far too casually.

A healthy person’s kidneys are very good at conserving magnesium when intake falls. Severe magnesium deficiency caused simply by eating too little is uncommon in otherwise healthy people.

But inadequate intake can certainly occur, and some people deserve a closer look.

Older adults are one group. Dietary intake may be lower, gastrointestinal absorption can decrease, and medications become more common.

People with certain gastrointestinal conditions can have trouble absorbing magnesium. People with type 2 diabetes can have increased magnesium losses in urine. Long-term heavy alcohol use can contribute to low magnesium status. Some medications can affect magnesium as well.

So I wouldn’t ask, “Is everybody deficient?”

I’d ask, “Is there a reason this particular person might not be getting or retaining enough?”

That is a much better question.

Your food can tell you quite a bit

Before opening a supplement bottle, look at what’s on your plate.

Pumpkin seeds, almonds, spinach, black beans, cashews, peanuts, edamame, whole grains, potatoes, yogurt and avocado are all dietary sources of magnesium.

Look at that list and then look at how you actually eat.

Someone regularly eating nuts, seeds, beans, greens and a varied whole-food diet starts in a very different place from someone surviving on coffee, sandwiches, packaged snacks and whatever is easiest at the end of the day.

And most of us have had periods of life when that second description was closer to reality than we’d like to admit.

Can you just get a blood test?

Sort of.

Here’s something I wish more supplement advertising explained: magnesium status isn’t particularly easy to measure.

Less than one percent of the body’s magnesium is found in blood serum. A serum magnesium test is useful for detecting significant abnormalities, but a normal serum level doesn’t necessarily tell you whether magnesium stores elsewhere in the body are adequate.

There are other ways to look at magnesium. One is RBC magnesium, which measures the magnesium inside red blood cells rather than the small amount circulating in serum. It can provide another piece of information when you’re trying to assess magnesium status, particularly when a serum magnesium result is normal but there is still reason to look more closely.

RBC magnesium can be useful, but it is still only one piece of the picture. There isn’t one perfect magnesium test. The NIH notes that no single method is considered completely satisfactory for assessing magnesium status.

That means evaluating magnesium may involve some combination of diet, medical history, medications, symptoms and laboratory information rather than chasing a single number.

If you want to check your RBC magnesium, you can order a Magnesium RBC test through Ulta Lab Tests.

I may earn a commission if you purchase testing through this link, at no additional cost to you.

And remember: a laboratory result is information. It still needs to be interpreted in the context of the person attached to it.

What about sleep?

This is probably one of the biggest reasons people are talking about magnesium right now.

Does magnesium help you sleep?

Maybe — but don’t turn “maybe” into “magnesium is a sleeping pill.”

A 2025 randomized, double-blind, placebo-controlled study looked specifically at magnesium bisglycinate in 155 adults who reported poor sleep. After four weeks, the people taking magnesium showed a statistically greater improvement on the study’s sleep-related questionnaire than those taking placebo.

But the effect was modest, not miraculous.

The researchers also found indications that baseline dietary magnesium intake may have influenced the response. That takes us right back to the question I started with:

What are we trying to fix?

If inadequate magnesium intake is part of the problem, replacing magnesium might help. If poor sleep is being driven by an underlying sleep disorder, alcohol, medications, mood issues, chronic pain, an erratic sleep schedule or scrolling your phone until 1:30 in the morning, magnesium isn’t going to magically erase the cause.

Sleep is complicated. Treat it that way.

Magnesium citrate, oxide, glycinate — does the form matter?

Yes, although the internet sometimes makes this sound more mysterious than it is.

Magnesium has to be combined with another substance in a supplement. That’s why you see names such as magnesium oxide, citrate, chloride, glycinate or bisglycinate.

Different forms have different absorption and gastrointestinal characteristics. A systematic review of magnesium supplements found that organic forms generally appeared to be better absorbed than inorganic forms.

Magnesium oxide is inexpensive and widely used but is generally less well absorbed than several organic forms. It can also have more of a laxative effect.

Magnesium citrate is generally well absorbed and is commonly used when the gastrointestinal effect isn’t necessarily undesirable.

Magnesium glycinate or bisglycinate combines magnesium with the amino acid glycine. It is a form many people choose when they want supplemental magnesium without deliberately looking for a laxative effect.

The larger point is this:

Don’t shop by the word “magnesium” alone.

Turn the bottle around. Look at the form. Look at the amount of elemental magnesium it actually provides. Look at what else is in the product. Then look at everything else you’re already taking.

The magnesium I use and recommend

The product I use and recommend through my practitioner store is Metagenics Magnesium Glycinate.

Each tablet currently provides 100 mg of magnesium as magnesium bis-glycinate. Metagenics’ suggested use is one tablet three times daily, or as directed by a healthcare practitioner, which would provide 300 mg of supplemental magnesium if three tablets are taken.

I like having the 100 mg tablets because supplementation doesn’t always need to be an all-or-nothing proposition. The appropriate amount depends on the person, the diet, other supplements, medications and the reason for using it.

Metagenics describes its Magnesium Glycinate as supporting normal muscle and nerve function and as a chelated form designed for better absorption and easier digestion than common forms such as magnesium oxide.

I carry it because I want a professional-quality magnesium option available when magnesium supplementation makes sense.

That does not mean I think everybody reading this should take three tablets tomorrow.

I sell the Metagenics products I recommend through my practitioner store and earn the retail margin on those purchases. That helps support the time I spend researching products, reviewing the evidence, developing supplement protocols and writing these articles so you can make more informed decisions, without adding a separate fee for that work.

You can browse my Metagenics practitioner store.

More magnesium is not automatically better

This is where supplement culture gets people into trouble.

If 200 mg is good, 800 mg must be spectacular.

It doesn’t work that way.

The National Institutes of Health sets the adult upper limit for magnesium from supplements and medications at 350 mg per day, unless a healthcare professional recommends otherwise. That upper limit does not include magnesium naturally present in food.

Why the limit? Supplemental magnesium in higher amounts can cause diarrhea, nausea and abdominal cramping. Extremely high amounts can become medically dangerous.

And remember the stacking problem.

Your magnesium supplement may contain 300 mg. Your multivitamin might contain more. Your nighttime powder might contain magnesium. Some antacids and laxatives contain magnesium too.

The body doesn’t care that you bought them in different bottles.

Add them up.

Medications matter

Magnesium can interfere with the absorption of some medications, which is another reason supplements should not be treated like candy.

Certain antibiotics need to be separated from magnesium supplements. Oral bisphosphonates used for osteoporosis can also be affected.

Diuretics can alter magnesium losses, depending on the type. Long-term use of some proton-pump inhibitors for acid reflux has also been associated with low magnesium levels.

And impaired kidney function changes the equation considerably because the kidneys are responsible for eliminating excess magnesium.

If you have kidney disease, take prescription medications, are pregnant or are being treated for a medical condition, this is a conversation worth having with your physician or pharmacist rather than an influencer.

So, do you need supplemental magnesium?

Maybe.

Look at what you eat first. Then look at your age, medications, gastrointestinal health, medical conditions and why you’re considering it.

If you’re taking it for sleep, understand that the evidence suggests the effect may be modest and that magnesium isn’t a substitute for figuring out why you’re not sleeping.

If you’re taking it because someone on social media told you virtually everyone is deficient, I would want a better reason.

If your diet is consistently low in magnesium-rich foods, you have risk factors for inadequate magnesium, or a healthcare professional has identified a reason to supplement, then choosing an appropriate form and amount makes sense.

That’s how I want to approach this entire supplement series.

What are we trying to accomplish?

My goal is to give you enough information to make a more intelligent decision about your nutritional supplementation.

Joyce Strong, RN, BSN
TotalWellCoach.com

Sources

National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals.

Schuster J, Cycelskij I, Lopresti A, Hahn A. Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. Nature and Science of Sleep, 2025.

Pardo MR, Garicano Vilar E, San Mauro Martín I, Camina Martín MA. Bioavailability of Magnesium Food Supplements: A Systematic Review. Nutrition, 2021.

Metagenics. Magnesium Glycinate — Supplement Facts and Product Information.

This article is for general educational purposes and is not a substitute for individualized medical advice. Supplements can interact with medications and may not be appropriate for everyone. Discuss supplement use with your physician, pharmacist or another qualified healthcare professional when appropriate, particularly if you have kidney disease, take prescription medications, are pregnant or are being treated for a medical condition.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.