There are more than 6 types of magnesium—which one do you need?

Why it deserves a spot in your supplement stack

An estimated 45% of Americans are deficient in magnesium—and it’s more than a nutrient gap, it impacts daily health. Magnesium is a mineral that is foundational to how your brain fires, how your muscles contract, how your gut digests, and how your heart maintains its rhythm. While magnesium supplements are having a moment, this isn’t just another health trend. Different kinds of magnesium target different problems—from constipation to stress; it's a powerful mineral that helps regulate the systems your body relies on every day.

But if you’re grabbing just any bottle off the shelf, you might be missing what your body uniquely needs. Each form has its own benefits. So we’re breaking it down—how to spot the signs of magnesium deficiency, how much you really need, and the six major types of magnesium—to help you find the right one for your supplement stack.

What does magnesium do for the body?

Magnesium powers over 300 biochemical reactions in your body. It regulates muscle and nerve function, blood sugar levels, blood pressure, and even how your DNA repairs itself. Without it, your body can’t efficiently create energy, stabilize mood, or maintain normal cardiovascular function. Magnesium is involved in nearly every major bodily system. That includes your bones (where 60% of your body’s magnesium is stored), muscles, brain, and gut.

Symptoms of low magnesium

The symptoms of low magnesium are easy to overlook. You can be deficient and not know it—simply because the symptoms often mimic other issues like anxiety, depression, or chronic fatigue. Common signs of deficiency include:

• Muscle cramps or stiffness
• Fatigue
• Loss of appetite
• Irritability
• Nervousness
• Headaches
• Increased sensitivity to stress
• High blood pressure
• Digestive issues like constipation

How much magnesium per day do you need?

For most adults, the recommended dietary allowance (RDA) is:

• Men: 400–420 mg/day
• Women: 310–360 mg/day
• If pregnant and magnesium deficient, consider talking to your healthcare provider about an optimal magnesium dose.

However, your magnesium needs may increase with certain factors:

• Stress
• High caffeine or excessive alcohol intake
• Intense exercise
• Medical conditions like kidney disease
• Medications like diuretics or proton pump inhibitors

Diet alone may not ensure adequate magnesium intake—especially if your consumption of magnesium-rich foods like leafy greens, seeds, and legumes is low. That’s why magnesium supplementation can be a game-changer—it can mean diminished brain fog, no more muscle cramps, and improved bowel movements. The tolerable upper intake level (ULs) for magnesium supplementation is 350 mg/day for those 18 years and older.  

A magnesium blood test can help you know for certain how much magnesium you’re getting and if supplementation is right for you. You can test your magnesium levels along with other essential micronutrients with Function. 

Six types of magnesium

Does magnesium help you sleep? It can, but it all depends on the magnesium supplement you take. Not all magnesium supplements are created equal. There are different types of magnesium supplements—choosing the right one depends on your body’s unique needs. Not sure which type you need? Read on.

1. Magnesium citrate: Constipation relief 

If you’re stressed, dehydrated, or simply not getting enough fiber in your diet, constipation can follow. Once your digestion slows, consider magnesium citrate.

Why it works:

Magnesium citrate is easily absorbed by the digestive tract—and draws water into the intestines to soften stools. This osmotic laxative effect helps to get things moving quickly. This magnesium type provides rapid relief for digestive issues.

Can be beneficial for:

• Occasional constipation
• Sluggish digestion
• Relief after overeating

Key insight:

Don’t overdo it. Too much magnesium citrate can lead to diarrhea and electrolyte imbalances. Always stay hydrated when using it. It should not be used for an extended period.

2. Magnesium glycinate: For stress and sleep

Does magnesium really help you sleep? It does. But unlike melatonin supplementation, you won’t wake up feeling groggy. The effect of magnesium glycinate is subtle—and helps you wind down from stress by promoting relaxation, allowing you to fall asleep. Consider this form a sleep aid and the best magnesium for sleep.

Why it works:

Bound to the amino acid glycine, it’s known for its natural calming properties. It’s absorbed well and gentle on digestion. Glycine supports GABA activity, a neurotransmitter that calms the brain and helps you ease into restorative sleep. 

Can be beneficial for:

• Situational stress
• Trouble sleeping
• Anxiety

Added benefit of magnesium glycinate:

Magnesium glycinate doesn’t have the laxative effect other forms do—so it’s safe for people with sensitive stomachs.

3. Magnesium malate: For muscle recovery and chronic muscle pain

Experiencing muscle stiffness after a difficult workout or muscle pain from cold weather? Magnesium malate is your go-to.

Why it works:

Magnesium malate contains malic acid, a compound involved in the Krebs cycle, your body’s primary cellular energy production system. It has also been found to relieve symptoms of fibromyalgia.

Can be beneficial for:

• Muscle soreness
• Post-workout recovery
• Fibromyalgia

4. Magnesium oxide: For indigestion

That burning sensation in your chest after a large meal? Magnesium oxide can help with that. This magnesium supplement is inexpensive and widely available—but may not be the best choice for boosting your overall magnesium levels.

Why it works:

Magnesium oxide has a higher elemental magnesium concentration but lower bioavailability. It can act as an antacid, help buffer excess stomach acid, and reduce symptoms of indigestion. 

Can be beneficial for:

• Occasional acid reflux
• Upset stomach
• Heartburn relief

5. Magnesium taurate: Strengthen heart health

Blood pressure creeping up? Heart racing at night? Magnesium taurate may be able to help. This form of magnesium has been shown to lower blood pressure and improve overall heart health.

Why It Works:

This form combines magnesium with taurine, an amino acid that supports cardiovascular function. Studies show that taurine and magnesium together can help stabilize cell membranes and promote healthy blood vessel dilation.

Can be beneficial for:

• Blood pressure support
• Heart palpitations
• Cardiovascular inflammation

If you have a family history of heart disease or are actively working on improving heart health, this form of magnesium is a great option.

6. Magnesium L-threonate: For long-term brain health

When your brain feels foggy or unfocused, magnesium L-threonate is the form designed to cross the blood-brain barrier and sharpen cognitive function. Unlike other forms, L-threonate has been shown to raise magnesium levels in the brain. It is linked to sharper memory, better focus, and enhanced mental processing—reducing the risk of cognitive decline.

Can be beneficial for:

• Cognitive support
• Alertness
• Memory enhancement
• Mental clarity, particularly under stress

Added benefits of Magnesium L-threonate

Enhanced sleep quality. This particular form of magnesium has been shown to improve deep and REM sleep—leading to better energy, mood, mental alertness, and daytime productivity.

Common magnesium questions & considerations

Can you take too much magnesium?

Yes. Too much supplemental magnesium can cause nausea, cramping, and diarrhea. In rare instances, excessive intake leads to more serious complications like low blood pressure or irregular heartbeat.

Pro tip: Start low and assess your body’s response. If you're getting this nutrient from multiple sources—supplements, multivitamins, food—be extra mindful so you can avoid the adverse effects of magnesium. 

When is the best time to take magnesium?

• For sleep: Take magnesium glycinate or magnesium L-threonate about 1–2 hours before bed.
• For digestion: Take magnesium citrate or oxide, once daily with meals.
• For muscle soreness: Magnesium malate works best post-workout or once situational muscle pain hits.

General rule: There’s no perfect time to take magnesium; simply supplement consistently. Your body builds up stores over time, and consistency matters more than exact timing.

Magnesium glycinate vs citrate: Which one's better?

It depends on the problem you’re trying to solve. 

• Need better sleep or stress relief? Magnesium glycinate.
• Dealing with constipation? Magnesium citrate.

Practical tip: You can rotate between them based on your needs—but avoid taking both simultaneously unless advised by your healthcare provider.

Magnesium and vitamin D: A critical pairing?

Vitamin D needs magnesium to activate. Without enough magnesium, vitamin D may remain in its inactive form. If you’re taking a vitamin D supplement but not getting results, magnesium may be the missing link. Many people have both low vitamin D and low magnesium—and correcting one without the other often leads to minimal progress.

Can lab testing measure magnesium levels?

Yes, Function members test magnesium the smart way—by measuring it inside red blood cells (RBCs), not just what’s circulating in the blood. This gives a more accurate picture of your body’s true magnesium levels; the storage and functional form of magnesium.  To find out if your magnesium is in the normal range, test your levels every 3-6 months. Function’s annual membership includes magnesium testing twice a year. 

Other forms (and what they do)

Not every magnesium type fits into a category. Some forms serve dual purposes or are better suited for niche cases. Other common forms include:

• Magnesium oil / magnesium spray - A topical magnesium often applied to sore muscles. It may be particularly helpful for people with digestive issues who struggle to absorb nutrients orally, or for athletes and chronic pain sufferers looking to ease localized discomfort.
• These additional forms of magnesium are inexpensive and often found in the supplement aisle at your local grocery store, but should be avoided because they’re poorly absorbed and can cause loose stools or diarrhea due to their strong laxative effects:
  
  • Magnesium carbonate
  • Magnesium sulfate
  • Magnesium gluconate

Takeaway

Nearly half of Americans are low on magnesium—and the symptoms are easy to dismiss as signs of stress or exhaustion. From digestion and muscle function to sleep and cognition, this mineral helps power essential functions that keep your body in balance. Magnesium is not only good for you—it’s essential for your body’s day-to-day health. Knowing the different magnesium types means you can choose the right supplement for your body—from magnesium citrate for constipation to magnesium malate for muscle pain— the right type can make all the difference. 

But here’s the move that matters most: test. Don’t take guesses at what your body needs. Magnesium is an essential nutrient, and tracking your levels over time gives you real insight—so you can supplement with precision. Advanced lab testing with Function makes that possible.