Magnesium: the foundational mineral most people are missing.

If you only ever take one mineral seriously, take magnesium. It is the supplement I would put in someone's hand before anything else — including the iodine. Most of the things people quietly suffer from — bad sleep, low mood, twitchy muscles, racing pulse at 3 a.m., the headache that shows up after a hard week — are magnesium showing its absence. Restoring it is one of the highest-leverage things a person can do for their body.

The case is not subtle. Dr. Mark Sircus, whose book Transdermal Magnesium Therapy is the closest thing to a comprehensive magnesium manual in the alt-health canon, writes that "massive magnesium deficiencies in the general population have led to a tidal wave of sudden coronary deaths, diabetes, strokes, and cancer." Dr. Eric Berg, working the same territory from a different angle, puts the rough figure at half the US population running below adequate magnesium. Whichever number you trust, the shape is the same: most people are under-supplied with the mineral their body uses in hundreds of reactions every minute.

The deficiency epidemic

Magnesium deficiency is not a quirk of the modern world; it is a feature of it. The reasons are simple and additive:

• Soil depletion. Industrial agriculture has been stripping mineral content from cropland for a hundred years. The broccoli your grandmother ate is not the broccoli at the grocery store. The mineral was never put back.
• Refined grains, processed foods, and sugar. The entire shelf-stable Western diet is built out of foods with most of the magnesium milled or refined out of them. Sircus is blunt: the modern food supply "contains minimal magnesium."
• Stress, alcohol, and intense exercise. All of these accelerate urinary magnesium loss. The harder you live, the faster you burn through what little you have.
• Common medications. Berg notes that diuretics, proton-pump inhibitors (PPIs like Prilosec), and certain antibiotics actively interfere with magnesium absorption. Many people are simultaneously eating a magnesium-poor diet and taking a daily pill that blocks what little they do get.
• Soft water. Magnesium and calcium in hard water used to provide a meaningful baseline. Filtered and softened water removes both.

Stack those together and the wonder is not that half the population is deficient. It is that the other half isn't.

What magnesium actually does

Magnesium is a cofactor in roughly three hundred enzymatic reactions — Sircus places the count at "hundreds" and goes as far as to say "there would be no life on earth without it." A short list of what those reactions actually power:

• Cellular energy (ATP). Every ATP molecule in your body is bound to a magnesium ion. Without magnesium, ATP is biologically inert. This is literally the energy currency of the cell.
• Heart rhythm and muscle contraction. Calcium makes muscle contract; magnesium lets it relax. The heart, the single most important muscle in your body, depends on the calcium–magnesium balance to keep its rhythm clean.
• Nervous system regulation. Magnesium gates the NMDA receptor in the brain. When magnesium is low, that gate stays open and the nervous system runs hot — anxious, twitchy, sleepless, sensitive to noise.
• Sleep. Magnesium is required for melatonin production and for GABA activity, the calming neurotransmitter that lets the brain quiet down at night.
• Bone strength. About 60% of the body's magnesium sits in bone. Calcium gets the publicity; magnesium is what actually keeps bone supple and able to absorb new mineral.
• Blood pressure and blood sugar. Magnesium is a natural vasodilator (it relaxes blood vessels) and a cofactor in insulin signalling. Low magnesium tracks tightly with both hypertension and type-2 diabetes.

The mild deficiency tell — what people blame on other things

The textbook signs of magnesium deficiency are the dramatic ones: muscle cramps, tetany, irregular heartbeat, numbness and tingling. Most people never get there. What they get instead — and what they almost universally blame on something else — is the picture Sircus spells out:

Read that list again. Sensitivity to noise. Irritability. Depression. Confusion. Insomnia. These are not exotic symptoms. These are the things people accept as their personality, their stress level, their age, the cost of being alive in 2026. For a great many of them, this is the first warning that their baseline magnesium has been low for years.

Berg, looking at the same clinical picture from a different angle, adds the more obviously physical tells: muscle cramps and spasms, high blood pressure, abdominal and digestive discomfort, migraines, irregular heartbeat, changes in blood sugar regulation, numbness or tingling in the extremities. If you can check off three or four of those, the burden of proof is on the explanation that isn't magnesium.

The form question — what to actually take

The single biggest mistake in supplementing magnesium is taking the wrong form. The shelf at most pharmacies is dominated by magnesium oxide, which is cheap, almost unabsorbed, and a reliable cause of the loose stool that has soured a generation on magnesium altogether. Berg ranks the forms cleanly:

• Magnesium glycinate — bound to the amino acid glycine. Highly absorbable, gentle on the gut, calming on the nervous system. Berg calls it "the best-tolerated option available" and the form he reaches for first for sleep, stress, and anxiety. This is the form to start with if you have never taken magnesium before.
• Magnesium L-threonate (Magtein) — the form that crosses the blood-brain barrier. Berg describes it as "neuroprotective" with effects on "synaptic plasticity" and mood. This is the night-time, cognition-and-sleep form.
• Magnesium chloride — Sircus's pick. The form used in injection, IV, transdermal oil, and bath flakes. He describes it as the most versatile, the form most directly useful as medicine, and the one he reaches for when speed matters.
• Magnesium citrate — well-absorbed, supports digestion, mild laxative effect. Good general daily option if you also want help with regularity.
• Magnesium malate — paired with malic acid; useful for energy and post-exercise muscle recovery.
• Magnesium taurate and orotate — cardiovascular forms, used by practitioners who specialize in heart-rhythm work.

And the ones to avoid as the main form of your protocol:

• Magnesium oxide — what supermarket multivitamins and most doctor-recommended supplements use. Low bioavailability, high GI side-effect rate. Berg ranks it the worst.
• Magnesium sulfate (Epsom salt) — fine for the bath, not for swallowing. Strong laxative.
• Magnesium carbonate / hydroxide — poorly absorbed, often used in antacids rather than as supplements.

The take-home: if a product label says oxide, put it back on the shelf. The forms that actually move the needle are glycinate, threonate, chloride, citrate, and malate, used for the jobs they're each best at.

Why transdermal is the fastest way to restore levels

Of all of Sircus's contributions to the magnesium conversation, this is the most important. Oral magnesium works, but slowly — the gut absorbs only a fraction of what you swallow, and the absorption you do get depends on having strong stomach acid, which most adults on a Western diet do not have. Transdermal magnesium — applied to the skin as oil, lotion, or in a bath — bypasses all of that.

Sircus cites work from Dr. Norman Shealy:

Four-to-six weeks versus four-to-twelve months. If you've been deficient for years, that is the difference between starting to feel like yourself this season and waiting until next year. Transdermal also avoids the laxative effect that limits how much oral magnesium most people can comfortably take in a day.

The practical methods, all interchangeable in mechanism:

• Magnesium oil spray. Spritz on skin (forearms, inner thighs, abdomen, behind the knees), let absorb for a few minutes, optionally rinse if it leaves a salty film. Each spray delivers roughly 18 mg of elemental magnesium. Five sprays in a glass of water is about 100 mg taken orally.
• Magnesium bath. Two to four pounds of magnesium chloride flakes in a hot bath (about 108°F), soak 20–30 minutes. Sircus's introductory protocol is a full body or foot bath every day for the first seven days, then a maintenance bath two or three times a week for six to eight weeks.
• Foot soak. If a full bath is impractical, a basin with a cup of flakes and warm water for 20 minutes works for daily maintenance.

And Sircus is explicit that the strongest protocol is both: "The best way is to combine one of the transdermal routes with oral for concentrated doses that achieve maximum therapeutic effect."

My protocol

Three layers, used together. I'll be honest about the topical piece because it matters: I currently use it less than I should.

1. Topical magnesium chloride — once a day, before the iodine. I dissolve Life-Flo magnesium chloride flakes in distilled water at home (the DIY recipe is below) and spritz the solution on my forearm right before painting on the two drops of Lugol's iodine. The magnesium primes the skin and the iodine goes on cleanly. This is once a day, and once a day is less than Sircus actually recommends. A full restoration protocol is closer to a full ounce of magnesium oil applied across the body daily — forearms, inner thighs, abdomen, behind the knees — for six months. There is no problem at all with applying topical magnesium multiple times a day; in fact, that is the protocol that actually moves the needle the way the four-to-six-week timeline above describes. I am working on doing this myself.
2. Magnesium L-threonate at night. One capsule of Double Wood Magtein — the bottle's serving size is four capsules (2,000 mg total), and I take one (roughly 500 mg of L-threonate). This is the form that crosses the blood-brain barrier, so I keep it for the evening when the cognitive and sleep effects matter most.
3. Magnesium glycinate as the daily backbone. One 120 mg capsule of Pure Encapsulations Magnesium Glycinate. This is the well-absorbed, gentle, no-laxative-effect baseline form. If a friend asked me which magnesium to start with and wanted only one answer, this is the answer.

How to make magnesium oil from flakes

Pre-made magnesium oil is fine but expensive for what it is. Making your own from flakes is twelve cents on the dollar and takes about ten minutes:

1. Bring 1/2 cup of distilled water to a boil.
2. Remove from heat. Add 1/2 cup of magnesium chloride flakes (a 1:1 ratio by volume). Stir until completely dissolved.
3. Let the solution cool to room temperature.
4. Transfer to a clean spray bottle. Glass is preferable to plastic.

That's the whole recipe. A spritz delivers roughly 18 mg of elemental magnesium. The solution keeps for several months at room temperature; refrigeration extends it further. If the residue on the skin feels itchy, dilute the next batch with a little more water — that is a sign of concentrated salt on dry skin, not a sign that the magnesium is too strong.

How to start — slow, with the laxative tell as your guide

Magnesium has one of the cleanest "you took too much" signals of any supplement: loose stool. Sircus is matter-of- fact about it — magnesium overdose, in his words, "at worst usually results in diarrhea." That makes dosing self-correcting. If you start loose, back off. If you don't, you have room.

A reasonable on-ramp:

• Week 1. 100–200 mg glycinate in the evening. A few sprays of topical magnesium on the forearms before bed.
• Week 2. Double the oral dose if the first week went smoothly. Add a second topical application during the day.
• Week 3 and beyond. Settle into 300–600 mg of oral magnesium daily across forms, plus full-body topical application once or twice a day. Add Magtein at night if you want the brain-and-sleep effect.
• If you go loose, drop the oral dose by 100 mg and stay there for a few days before climbing again. The topical does not cause this; only oral does.
• Give it weeks, not days. Two to four weeks is when most people notice they sleep deeper, wake less, and stop twitching at night.

What I actually take

Three products. The first one is the most important because it is how the protocol stops being abstract and starts being something you can actually put on your skin tonight.

Closing

Magnesium is foundational in the most literal sense — it is the mineral that lets ATP do its job, that lets the heart relax between beats, that lets the nervous system shut down at night. The reason so many people feel persistently off in ways they cannot quite name is that the mineral underneath every one of those processes has been quietly under-supplied for years.

The good news is that it is one of the easiest deficiencies to actually correct. Magnesium does not need a prescription. It does not need a doctor. It does not need a protocol more complicated than "the right form, taken regularly, with the topical on top of it." Most people who put magnesium back into their body notice within a month, and the cost of trying — a bag of flakes, a bottle of glycinate — is trivial relative to what is on the line.

If you are going to start with one mineral, start with this one.

Related reading on this site: the sleep article covers why evening magnesium glycinate is one of the most effective sleep-support interventions available. The weight lifting and testosterone articles cover magnesium's role in muscle recovery, hormonal cofactor support, and free-testosterone availability. The women's cycle article covers magnesium as the single most-studied mineral for PMS relief.