Types of Magnesium: A Comprehensive Guide

Ever wonder why some magnesium supplements make you feel amazing—and others just make you run to the bathroom?

If you've stared at a wall of supplement bottles wondering what the heck "magnesium glycinate" vs "magnesium citrate" even means, you're in good company. Magnesium is one of those essential minerals everybody talks about, but almost no one breaks down in plain English.

I used to think magnesium was just magnesium. One chalky tablet a day—boom, done. But it turns out, there are actually several different types, and they all do different things in your body. Some are calming. Some help with digestion. Some barely absorb at all. And yes, some will send you sprinting to the bathroom if you're not ready for it.

So here’s the lowdown—no medical jargon, no unrealistic promises. Just helpful info on the types of magnesium out there, and how to find the one that works best for your body and goals.

Why magnesium matters (without getting too science-y)

Magnesium plays a role in hundreds of functions in the body. Like, literally—over 300 enzyme systems rely on it to do their job. It helps your muscles relax, supports healthy energy levels, and—it’s true—can help calm a racing mind at night¹.

Thing is, most of us aren’t getting enough from food alone. Processed foods, depleted soils, chronic stress—it all adds up. So supplementing can make a noticeable difference. The key? Picking the right type for your needs.

Let’s walk through the most common ones and what they’re best for.

Magnesium glycinate: your chill-out supplement

This one is my personal favorite. Magnesium glycinate is bound to the amino acid glycine, which has calming properties on its own². Together, they're like the tag team of chill.

Many people take it before bed to unwind and support better sleep. It doesn’t have a laxative effect like some other forms (hello, magnesium citrate), so you can take it without worrying about racing to the bathroom.

If you’re feeling anxious, wired, or just mentally tapped out, this is a gentle form that’s easy on the stomach and nice for winding down.

Magnesium citrate: support for digestion

This form is more bioavailable than many others, meaning your body absorbs it pretty easily³. But here’s the big thing with citrate: it attracts water into the intestines. That makes it super helpful if things aren't, uh, moving along as they should.

Many people use it for occasional constipation or digestive sluggishness. But start slow—too much can definitely backfire. Yes, I learned that the hard way.

Pro tip: Take it with plenty of water, and ideally not right before a long car ride.

Magnesium threonate: brain support

Magnesium threonate is the brainy one.

It’s been shown to cross the blood-brain barrier more efficiently, which might explain its connection to cognitive support⁴. Some people take it to help with focus, memory, and mental clarity. The research is still young, but promising.

It’s often a little pricier than other types, and usually comes in multi-capsule doses. So if your main goal is sharper thinking or brain support, this one's worth looking into. Not necessary for everyone, but interesting if you’re curious about nootropics or just want a little more clarity upstairs.

Magnesium malate: for energy and muscle function

When you combine magnesium with malic acid—which is found naturally in fruits—you get magnesium malate. That combo may support energy production in your cells and help reduce muscle tension⁵.

Some people find this form helpful if they're active, sore from workouts, or dealing with low energy. It's not a sedating type like glycinate, so many prefer it in the morning or during the day.

It’s a nice all-rounder if you want energy support without any digestive side effects.

Magnesium oxide: cheap, but not always effective

This one shows up everywhere because it’s inexpensive and heavily used in multivitamins. But here’s the deal—it’s not very bioavailable. That means your body doesn’t absorb much of it⁶.

So yeah, you might technically be "getting" 400mg of magnesium if your label says so, but your body might only absorb a small fraction of that.

It also has a strong laxative effect for some people. If you’ve taken magnesium and ended up regretting it shortly after, it was probably this one.

Magnesium chloride: hydration and topical use

This form’s a bit of a wild card. Internally, it’s decently bioavailable and gentle on the stomach. But it also shows up in liquid drops that you can add to water, or in topical sprays and lotions.

Topical magnesium is popular for sore muscles or before bed rituals, even though the research on absorption through skin is mixed⁷.

Still, anecdotally, lots of folks swear by magnesium sprays or Epsom salt baths. If you don’t love pills or powders, chloride might be your low-effort ticket to getting some magnesium into your routine.

How to actually choose the right magnesium for you

Here’s the cheat sheet:

• Feel tense or have trouble sleeping? Try magnesium glycinate.
• Need digestive help? Magnesium citrate can move things along.
• Want brain support? Magnesium threonate is your go-to.
• Feeling run-down or sore post-workout? Magnesium malate might help.
• Just want a basic, affordable supplement? Be cautious of magnesium oxide.
• Hate swallowing pills? Consider chloride-based sprays or drops.

As always, start slow. Magnesium can have different effects for different people. Too much too fast can cause loose stools, bloating, or nausea, even with the gentler forms.

Start with one type, give it a week or two, and see how you feel. Your body will usually let you know pretty quickly what it likes—or doesn’t.

What I noticed after switching types

I used to take generic magnesium oxide and wondered why I felt nothing. Then I switched to glycinate, and within a couple nights, I started sleeping more deeply and feeling less twitchy at bedtime. Now it’s one of my desert island supplements.

Everyone’s experience is different, but once you find the type that clicks, it’s oddly satisfying. Like, “Okay yeah, that’s what magnesium is supposed to feel like.”

Sources

[1] Magnesium in Man: Implications for Health and Disease – Physiological Reviews. 2001. https://journals.physiology.org/doi/full/10.1152/physrev.2001.81.1.1
[2] Effect of glycine on the subjective and objective sleep quality – Sleep and Biological Rhythms. 2007. https://pubmed.ncbi.nlm.nih.gov/25653582/
[3] Magnesium bioavailability from magnesium citrate and magnesium oxide – Magnes Res. 2001. https://pubmed.ncbi.nlm.nih.gov/11794633/
[4] Elevation of brain magnesium prevents and reverses cognitive deficits in Alzheimer's disease mouse model – Neuron. 2010. https://pubmed.ncbi.nlm.nih.gov/20399770/
[5] The role of malic acid in the energy production cycle – Journal of Nutritional Biochemistry. 1995. https://pubmed.ncbi.nlm.nih.gov/7554241/
[6] Bioavailability of magnesium diglycinate vs. magnesium oxide in healthy adults – Magnesium Research. 2003. https://pubmed.ncbi.nlm.nih.gov/12908744/
[7] Efficacy of transdermal magnesium – Magnesium Research. 2017. https://pubmed.ncbi.nlm.nih.gov/29199042/

Try one you haven’t before. Ask yourself how you want to feel—calmer, clearer, more regular? There’s probably a magnesium for that.

And hey, if you find the one that works best for you, tell a friend. It might just save them from a surprise bathroom dash.