The Magnesium Cheat Sheet: Finding the Type That Actually Works for You

If you've ever stood in the supplement aisle staring at a wall of magnesium options, wondering what the difference actually is, you're not alone. Glycinate, citrate, oxide, sulphate, chloride - they're all magnesium, but what they do for your body is a very different story.

Some are amazing for sleep. Some are better for digestion. One is largely a waste of money. And two of them don't even go through your digestive system at all.

Here's a simple breakdown of what each of the most common forms actually do, and who they might be best suited for.

The Oral Forms

Most people start their journey here as it’s the most traditional way to supplement magnesium. These forms have to travel through your stomach and intestines before they can get to work.

Magnesium Glycinate

This is the form most commonly recommended by practitioners for people dealing with stress, anxiety, poor sleep, or low mood - and there's solid science behind why.

Glycinate is what's called a chelated form, which means the magnesium is bound to an amino acid called glycine. That binding process does two important things. First, it protects the magnesium as it moves through your digestive system, so significantly more of it actually makes it into your cells rather than getting lost along the way. Second, glycine itself is an inhibitory neurotransmitter, which means it actively calms your nervous system down. So you're essentially getting a double effect: magnesium doing its job as the body's relaxer, and glycine reinforcing that signal.

It also happens to be one of the gentlest forms on the stomach, which makes it a good option for people who've had trouble with other supplements in the past. If sleep is your main concern, or you're navigating anxiety or perimenopause, this would be a great form to look at.

Best for: sleep, anxiety, stress, mood & perimenopause symptoms

Magnesium Citrate

Citrate is one of the most widely available forms and one of the better absorbed oral options. The citric acid it's bound to draws water into the intestines, which helps stimulate movement in the bowel (a bit like your morning coffee) - making it effective for constipation and sluggish digestion.

Interestingly, it's also helpful for kidney stone prevention as it keeps calcium dissolved in your bloodstream rather than letting it crystallise into stones.

The tradeoff is that the same thing that makes it good for digestion can also cause loose stools if you take too much. It's generally well tolerated at moderate doses, but it's worth starting low and building up.

Best for: constipation, digestive support, kidney stone prevention

Magnesium Oxide

This is the form you'll find most often in cheap supermarket supplements, which is frustrating because it's arguably the least effective for actually correcting a deficiency.

Oxide has a high concentration of elemental magnesium by weight, which looks good on a label. The problem is that only around 4% of it is actually absorbed by your body. The rest stays in your intestines, where it acts as a powerful laxative. That's not a side effect - that's essentially what it's doing.

It does have legitimate uses as a short-term antacid or as a treatment for acute constipation. But if you're taking it hoping to top up your magnesium levels, you're largely getting very expensive trips to the bathroom. If you've been taking magnesium for a while and not feeling much difference, it's worth turning the bottle over and checking what form you're actually taking. Oxide is unfortunately far more common than it should be.

Best for: short-term constipation relief, antacid use - not for correcting deficiency

The Topical Forms

There's a whole category of magnesium that works completely differently to everything above. Rather than passing through your digestive system, topical magnesium absorbs directly through the skin - which means no gut involvement, no laxative effect, and no waiting for it to be processed before it reaches your muscles and tissues. For anyone who struggles to swallow tablets, or who wants fast, targeted relief in a specific area, this is where it gets interesting.

Magnesium Chloride

Magnesium chloride is the most bioavailable of the topical forms. Which basically means it’s something your body can actually absorb and use effectively. It absorbs through the hair follicles and outer layers of the skin and enters the muscles and tissues directly.

For localised pain - a tight neck, cramping calves, sore shoulders - this is often the most practical option because you can apply it exactly where you need it. Research has shown that magnesium chloride acts as an NMDA receptor antagonist, which in plain terms means it can interrupt the pain signalling pathway and reduce inflammation where you apply it.

It's also become a popular part of evening routines for a good reason - applying it to your legs or low body before bed helps ease the physical tension that often keeps people lying awake.

For correcting a significant deficiency, most practitioners recommend combining it with an oral form - but as part of a broader routine, it's one of the most practical and immediate options available.

Best for: muscle soreness, localised pain, sports recovery, restless legs, winding down before sleep, sensitive stomachs

Magnesium Sulphate (Epsom Salts)

You've almost certainly come across this one, even if you didn't realise it. Epsom salts - the stuff people pour into their baths after a hard day or a tough training session - is magnesium sulphate, and it's been used for detoxification for centuries.

As a bath soak, it works through the skin in a similar way to topical chloride, though it doesn't penetrate as deeply into the cells. Its molecular structure means it tends to interact more with the surface layers of tissue - so it's excellent for drawing out inflammation, but magnesium chloride flakes are generally considered the stronger option for deeper, muscular relief.

Interestingly, Magnesium Sulphate is also found in many household staples like laundry detergent - but where it really earns its place is in the sulphate part of the equation. Sulphur is the fourth most abundant mineral in the human body and a critical building block for glutathione - your body's master antioxidant, responsible for neutralising free radicals and supporting detoxification. Many people are quietly deficient in sulphur without even knowing it.

A Epsom bath soak can be genuinely useful, just with realistic expectations: it's amazing for relaxation, soreness, and inflammation, but it's not doing the heavy lifting of correcting a deficiency the way a topical chloride or an oral form would.

So Which One Do You Actually Need?

Struggling to sleep or feeling anxious and wired? Glycinate.
Digestive issues or concerned about kidney stones? Citrate.
Found magnesium oxide in your cupboard? It might be time to swap it out.
Sore muscles, post-training recovery, or a sensitive stomach? Topical chloride.
Looking to support detoxification? Epsom salt bath.

Some people do well with a combination - an oral form for systemic support and a topical spray for targeted relief. Others find one form covers everything they need. There's no universal answer, but knowing what each type actually does means you're making a choice based on your body rather than just grabbing whatever's on the shelf.

If you're not sure where to start, we stock a range of magnesium forms across both oral and topical - so whatever your body needs, there's likely something in our range that’s right for you.