Magnesium is the fourth most abundant mineral in the human body and a cofactor for over 300 enzymatic reactions — from ATP energy production and DNA synthesis to muscle contraction, nerve signalling, blood glucose regulation, and blood pressure control. Your body holds roughly 25 grams of it at any given time: about 63% stored in bone, 27% in muscle, and only around 1% floating in your blood.
That last detail matters. Standard blood tests measure serum magnesium, which reflects just 1% of your total body stores. This means subclinical deficiency — being meaningfully low without it showing up on routine bloodwork — is far more common than most people realise.
Researchers have called it a public health crisis, directly linking it to cardiovascular disease risk. Common dietary sources include leafy greens, nuts, seeds, and whole grains, but modern diets and declining soil mineral content have made it increasingly difficult to hit adequate intake through food alone.
Dr. Peter Attia, physician and longevity expert, has dedicated a full episode on magnesium on his podcast The Drive, covering its roles in the body and why so many people fall short. It is one of the few supplements that appears consistently across longevity-focused protocols — and for good reason.
The evidence base for magnesium’s role in long-term health is broad and unusually strong for a single mineral. A dose-response meta-analysis of prospective studies found that each additional 100 mg per day of dietary magnesium was associated with a 10% lower risk of all-cause mortality, a 7% lower risk of stroke, a 22% lower risk of heart failure, and a 19% lower risk of type 2 diabetes. A separate mortality meta-analysis covering over 1.17 million participants confirmed a 6% reduction in all-cause mortality and a 5% reduction in cancer mortality per 100 mg daily increase. These are observational findings — not proof of causation — but the consistency across large populations is hard to ignore.
Beyond cardiovascular and metabolic risk, magnesium plays a meaningful role in inflammation. A 2022 inflammation meta-analysis of randomised controlled trials found that magnesium supplementation significantly decreased C-reactive protein (CRP), a key marker of systemic inflammation, and increased nitric oxide levels — both relevant to cardiovascular health and healthy aging.
Magnesium also supports sleep quality, one of the most underrated pillars of longevity. Subclinical deficiency — estimated to affect 10–30% of the general population, and potentially up to half of adults in developed countries — is linked to accelerated aging, chronic inflammation, and metabolic dysfunction.
As Attia put it on his podcast: “The more deficient you are in magnesium, the more you will be helped by supplementing magnesium.” He has also said in an interview: “I think most people probably would benefit from magnesium.”
Andrew Huberman shares a similar view. On The Tim Ferriss Show, he said: “There are three things that I personally have found to be much more beneficial that seem to have very good safety margins… those three things are magnesium threonate… or bisglycinate, magnesium bisglycinate.”
Bryan Johnson includes magnesium in his Blueprint protocol, using 150 mg of magnesium citrate daily in his core stack plus an additional 100–200 mg as needed for mood and sleep support. David Sinclair has highlighted the importance of monitoring for deficiencies in key minerals including magnesium as part of a broader health monitoring approach.
The research on magnesium supplementation spans blood pressure, inflammation, insulin sensitivity, sleep, mood, and mortality risk. Here is what the strongest evidence supports.
A 2025 blood pressure meta-analysis published in Hypertension (the American Heart Association journal) reviewed 38 randomised controlled trials involving 2,709 participants. It found that magnesium supplementation significantly reduced blood pressure, with a median dose of 365 mg and a median intervention period of 12 weeks. This is one of the clearest intervention-level findings for magnesium.
The 2022 inflammation meta-analysis of RCTs confirmed a significant decrease in CRP and an increase in nitric oxide levels with magnesium supplementation. A 2025 oxidative stress review further supported magnesium’s role in reducing oxidative stress and inflammation markers.
A 2016 insulin sensitivity meta-analysis of RCTs found that magnesium supplementation for four months or longer significantly improved the HOMA-IR index (a measure of insulin resistance) and fasting glucose in both diabetic and non-diabetic subjects. For anyone concerned about metabolic health, this is relevant.
The large observational meta-analyses described above — covering over a million participants — consistently associate higher magnesium intake with lower all-cause, cardiovascular, and cancer mortality. These are not clinical trials, so they cannot prove supplementation directly extends life, but the pattern is consistent and dose-dependent.
A 2021 sleep meta-analysis found that magnesium supplementation in older adults reduced sleep onset latency by approximately 17 minutes compared to placebo. A 2025 bisglycinate sleep trial — a randomised controlled trial of 155 participants testing 250 mg of elemental magnesium from bisglycinate — found modest but statistically significant improvement in insomnia severity at four weeks, with greater benefit in those who had lower baseline dietary magnesium intake. The effect size was small (Cohen’s d = 0.2), so expectations should be realistic: magnesium is not a sedative, but it may help people who are already running low.
A depression meta-analysis found that magnesium supplementation produced a significant decline in depression scores in adults with depressive disorder, though the number of included RCTs was limited. This is encouraging but should be treated as emerging rather than definitive.
An umbrella review of systematic reviews and meta-analyses concluded that the strongest GRADE-level evidence supports magnesium for reducing migraine frequency and reducing hospitalisation risk in pregnancy. Evidence for other outcomes ranged from moderate to suggestive — which is honest about where magnesium stands: well-supported for certain outcomes, promising but not yet conclusive for others.
Not all magnesium supplements are the same. The form determines how much your body actually absorbs and how well you tolerate it.
Magnesium bisglycinate (glycinate chelate) is the recommended form. The magnesium is bound to two glycine molecules, forming a chelate that the body absorbs efficiently. A bioavailability review confirmed that organic magnesium salts — including bisglycinate — generally have higher bioavailability than inorganic forms. A separate bioavailability study found bisglycinate achieved approximately 67% bioavailability in vitro, significantly outperforming oxide. A clinical comparison of magnesium forms further supports this ranking. Bisglycinate is also gentler on the stomach than citrate or oxide, and the glycine component may offer additional calming benefits.
Magnesium threonate (L-threonate) is primarily valued for its ability to cross the blood-brain barrier, making it a popular choice for cognitive support and sleep. It delivers less elemental magnesium per dose and costs more.
Magnesium citrate has reasonable bioavailability but is more likely to cause loose stools. It is often used when bowel regularity is also a goal.
Magnesium oxide has the highest elemental magnesium content per capsule but very low bioavailability — roughly 4%. It functions mainly as a laxative. It is also the cheapest form and the one most commonly found in budget products.
Magnesium chloride offers decent bioavailability. Attia personally uses this form (SlowMag) as part of a multi-form approach, as he told Business Insider.
Dr. Andrew Huberman, neuroscientist at Stanford University, has been specific about his preferences. On The Tim Ferriss Show, he said: “Magnesium threonate, or magnesium bisglycinate, so 200 to 400 milligrams, about 30 minutes before sleep, is a powerful sleep aid.” He has further described on his podcast using “50 mg of apigenin, 300–400 mg of magnesium threonate or bisglycinate, and 200–400 mg of theanine” as his go-to evening stack, calling it “the best way to consistently fall asleep quickly and stay asleep most if not the entire night.”
When buying, look for “magnesium bisglycinate chelate” or “magnesium glycinate” on the supplement facts panel — not just the front label. Check that the formulation does not include magnesium oxide as a hidden ingredient.
Dose range: 200–400 mg of elemental magnesium per day from bisglycinate is the range most commonly recommended in the longevity space. The NIH fact sheet sets the Recommended Dietary Allowance at 400–420 mg per day for adult men and 310–320 mg per day for adult women (total from diet and supplements combined). The tolerable upper intake level for supplemental magnesium is 350 mg per day, though higher doses are used clinically under supervision.
Timing: If you are using magnesium primarily for sleep, take it 30–60 minutes before bed. For general daily support, it can be taken with a meal.
Frequency: Daily, consistently. The research on sleep and inflammatory markers typically shows results after four or more weeks of daily use.
Huberman has offered specific guidance. In his sleep toolkit, he recommended: “145mg Magnesium Threonate or 200mg Magnesium Bisglycinate is great as a starting place. I would only take the minimum needed for great sleep.”
That start-low principle is sound. Begin with 200 mg of elemental magnesium and increase to 400 mg if tolerated and needed. If you experience any GI discomfort at higher doses, split it across two servings — for example, one with dinner and one before bed.
Attia takes a multi-form approach: he uses two or three magnesium chloride pills daily alongside magnesium L-threonate and some magnesium oxide, as he told Business Insider. For most people, a single well-absorbed form like bisglycinate at 200–400 mg daily is a simpler and effective strategy.
Magnesium bisglycinate fits most easily into an evening routine. Take 200–400 mg of elemental magnesium 30–60 minutes before bed, with or without food. Taking it with a meal may slightly improve tolerance, but it is not strictly necessary with the bisglycinate form.
If sleep is not your primary goal, taking it with breakfast or dinner is equally fine. The key is consistency — pick a time you will not forget and stick with it.
Who benefits most: People with poor or inconsistent sleep. People under chronic stress. Active individuals who lose magnesium through sweat. Older adults, since absorption decreases with age. Anyone whose diet is not consistently rich in leafy greens, nuts, seeds, and whole grains — which realistically applies to most people.
Stacking notes: Magnesium pairs naturally with vitamin D, since your body requires magnesium to metabolise vitamin D properly. It also works well alongside omega-3 and other foundational longevity supplements. Huberman’s evening stack — 50 mg apigenin, 300–400 mg magnesium bisglycinate or threonate, and 200–400 mg theanine — is one of the more widely discussed supplement combinations for sleep support.
Effects typically build over weeks. The bisglycinate sleep trial measured outcomes at four weeks. Do not expect dramatic results after a single dose — this is a daily habit, not a quick fix.
Magnesium oxide labelled simply as “magnesium.” This is the most common trap. Budget products in pharmacies and supermarkets across Cyprus often contain magnesium oxide as the primary form. The label might say “Magnesium 400 mg,” which sounds impressive — but oxide has roughly 4% bioavailability. You absorb almost nothing. It works as a laxative, not a supplement.
This is a bigger problem than most buyers realise. ConsumerLab testing found that multiple popular magnesium supplements labelled as “glycinate” did not pass testing because cheaper oxide appeared to be present instead. NOW Foods, a major supplement manufacturer, publicly acknowledged the issue through industry testing: “Unfortunately, it is known in the industry that many brands either knowingly or unknowingly simply blend glycine with magnesium oxide or carbonate and then label the product as ‘Magnesium Glycinate.'”
Some products list magnesium bisglycinate on the front label but include magnesium oxide as a “buffer” in the supplement facts panel. This is a legal loophole that lets manufacturers increase elemental magnesium content per capsule at lower cost — while diluting the chelated proportion and lowering overall bioavailability. Always check the supplement facts, not just the front of the bottle.
Some labels list the total weight of the chelate compound rather than the elemental magnesium content. A product stating “1000 mg magnesium glycinate” per serving might contain only 100–140 mg of actual elemental magnesium. Look for “elemental magnesium” clearly stated on the label.
These often combine small amounts of premium forms (like glycinate or threonate) with cheap filler forms (oxide, carbonate) without disclosing how much of each is included. The label looks impressive; the product is not.
Magnesium bisglycinate is one of the best-tolerated forms. Side effects are uncommon at recommended doses, but they can include mild GI symptoms — diarrhoea, nausea, or abdominal cramping — particularly at higher doses. These effects are far more common with oxide and citrate forms.
This content is for educational and informational purposes only and is not medical advice. Supplements do not replace a balanced diet and healthy lifestyle. If you are pregnant, breastfeeding, taking medication, or managing a medical condition, consult a qualified healthcare professional before use. Results and suitability vary by individual.
Most pharmacies in Cyprus carry magnesium oxide or citrate — the cheapest forms with the lowest absorption. Finding a genuine bisglycinate chelate locally is harder than it should be.
Longevity.cy stocks magnesium bisglycinate chelate — the same form recommended by longevity-focused physicians and neuroscientists like Attia and Huberman — at 200–400 mg of elemental magnesium per daily serving. No hidden oxide. No proprietary blends. The supplement facts panel matches what is on the front of the label.
Longevity.cy selected this form specifically to match what the evidence and expert guidance support. If you are looking for a magnesium supplement in Cyprus that you do not have to second-guess, this is the straightforward option.
