IO Genix Magnesium Citrate

What is IO Genix's Magnesium Citrate?

It is a magnesium supplement in tablet form, dosed at 375 mg of magnesium per two tablets, which is exactly 100% of the nutrient reference value. The bottle holds 60, covering 30 days at the recommended dose.

The composition fits in two lines: magnesium citrate and silicon dioxide as an anti-caking agent. No colouring, no preservative, no sweetener. It is a formula with no dressing up, and on a mineral that is rather good news: you are paying for the magnesium, not the coating.

Citrate is a salt of magnesium and citric acid. It stands apart from the other forms in this section on two counts, one good and one to be aware of: it is well absorbed, and it speeds up transit. The rest of the Spanish range can be found in our IO Genix section.

What is in a two-tablet dose?

* Column calculated from the value declared for two tablets. Other components: magnesium citrate, anti-caking agent (silicon dioxide). NRV for magnesium within the meaning of Regulation 1169/2011: 375 mg. Packaging: 60 tablets, i.e. 30 doses.

Here is a case where the figure calls for a frank explanation, because it is higher than what you usually see. 375 mg of magnesium in a single dose is 100% of the European reference value — and it is also above the 250 mg a day that EFSA sets as the safety limit for magnesium supplied by supplements. These two benchmarks do not say the same thing and are often confused: the NRV is a labelling reference, the EFSA limit a threshold of digestive tolerance.

In practice that means two things. First, a single tablet, at 187.5 mg, stays within bounds and already covers half the reference value — a perfectly sensible option, and often the right one. Second, if you take both tablets and you are also taking a multivitamin or a ZMA containing magnesium, do the sum: stacking is the real trap with this mineral.

On what magnesium does, European regulation is precise and generous: magnesium contributes to a reduction of tiredness and fatigue, to the normal functioning of the nervous system, to normal muscle function, to electrolyte balance, to normal energy-yielding metabolism, to normal psychological function, to the maintenance of normal bones and to normal protein synthesis. Those are the exact wordings, and they are enough.

A final word on what you will not see here: the weight of the citrate salt is not published, only elemental magnesium. That is the right way to do it, and it deserves credit — plenty of labels display the big salt figure in the hope that it will be mistaken for the mineral.

How do you take Magnesium Citrate?

Dose: 2 tablets, or 1 to start with. Liquid: a large glass of water. Timing: 30 minutes before bed. Frequency: once a day. Duration: a 30-day course, repeatable as needed.

Our advice, and it differs slightly from the label: start with a single tablet for a week. Citrate speeds up transit, that is its signature, and 375 mg all at once causes loose stools in some people from day one. At 187.5 mg tolerance is much better, and you can then see whether you need the second.

If you do take both tablets, split them — one at midday, one in the evening. That improves digestive tolerance more reliably than any change of form, and absorption is slightly better for it.

Three combination instructions given by the manufacturer, and they are sound. Leave two hours between this and any calcium, iron or zinc you take: these minerals compete for the same transporters. Avoid very high-fibre meals at the same time, since phytates reduce absorption. And drink enough throughout the course.

On the time of day, the manufacturer settles on the evening. That is a convenient habit rather than a necessity: magnesium has no acute effect, and what counts over thirty days is not forgetting it. Take it whenever you will remember.

Who is this magnesium for, and who is it not for?

It suits those who want a straightforward dose and a simple product, with no additives and no capsule, and those whose transit is on the slow side — the accelerating effect of citrate then becomes an advantage rather than a drawback. It also suits people who sweat a lot or who are in a prolonged calorie deficit, two situations in which intake drops.

It is not recommended in cases of severe renal insufficiency: that is the contraindication carried by the manufacturer, and it is essential. The kidney is the route by which magnesium is eliminated; when it works poorly, magnesium accumulates. If you are on medical treatment, consult a healthcare professional — magnesium notably interferes with the absorption of thyroid hormones, of certain antibiotics and of bisphosphonates taken at the same time. Traces of gluten, egg, milk, fish and soya are possible.

It is not for you if you have a sensitive gut or an already rapid transit. That is the real limit of this form, and we would rather say so before purchase than after: at 375 mg of citrate, digestive discomfort is common. In that case a bisglycinate will suit you far better.

What not to expect from it. It is not a sleeping aid: the evening dose is a habit, not a demonstrated effect, and no claim about sleep is authorised. If your problem is falling asleep, our melatonin section answers the question better. Nor is it a treatment for exercise cramps: those come down first of all to hydration and sodium losses, which our electrolytes cover. And it is not a performance product: securing an intake is not the same as moving heavier loads.

Magnesium citrate or bisglycinate?

This is the only trade-off that really matters in this section, and it is not settled on absorption — both forms are properly absorbed — but on transit and on price.

Bisglycinate is magnesium chelated to two glycine molecules. It is the best-tolerated form in the magnesium section, the one that causes the fewest loose stools, and it is the better choice if your gut is sensitive, if you have tolerated a magnesium badly in the past, or if you are planning a long course. Its drawback: the salt weighs a lot for little mineral, which means multiplying the capsules, and it costs considerably more per milligram of elemental magnesium.

Citrate, the form on this page, does exactly the opposite. It reaches 375 mg in just two tablets and costs far less. Its accelerating effect on transit is a real drawback for some and an advantage for others — if you tend towards constipation, this is the form you want, and nobody is going to say so on your behalf.

The practical advice: start with citrate, at one tablet. It is cheaper, and within a week you will know whether you tolerate it. If the answer is no, move to bisglycinate without hesitating. And if your needs also cover zinc, a ZMA brings the two minerals together in one dose, at the cost of absorption competition between them. The vitamin D section usefully rounds the whole thing out in winter.

Frequently asked questions

375 mg a day, isn't that too much?

It is 100% of the nutrient reference value, but above the 250 mg a day that EFSA sets as the limit for magnesium supplied by supplements. A single tablet, at 187.5 mg, stays under that threshold and already covers half the reference. Start there, and only add the second if you tolerate it well.

Why does citrate cause loose stools?

Because it exerts an osmotic effect in the gut: it draws water into the intestinal lumen and speeds up transit. That is not a manufacturing fault, it is a property of the form, known and predictable. It eases off if you split the dose and take the tablets during a meal.

Should it be taken on an empty stomach or with food?

The manufacturer advises an empty stomach for absorption, and avoiding very high-fibre meals. In practice, if taking it on an empty stomach gives you loose stools, take the tablets in the middle of a light meal: you will lose a little on absorption, and you will get through the thirty-day course.

How long does a bottle last?

Thirty days at two tablets a day, sixty if you take only one. The manufacturer settles on a repeatable thirty-day course; with a mineral you have to think in weeks, since no effect shows up within a few days.

Does magnesium help you sleep?

No claim of that kind is authorised, and we are not going to make one. The permitted wordings speak of normal functioning of the nervous system and normal psychological function, which is not a sedative effect. The evening dose recommended by the manufacturer is a matter of habit, not of demonstration.

Can it be combined with a multivitamin?

Yes, but do the sum first. Most multivitamins already contain 50 to 100 mg of magnesium, and many ZMAs provide 150 to 450 mg. Stacking two sources takes you easily beyond EFSA's 250 mg limit, with digestive discomfort as the only result.

Is the product suitable for vegetarians?

These are tablets, not capsules: there is therefore no gelatine shell. The composition consists only of magnesium citrate and silicon dioxide, two ingredients of non-animal origin. The manufacturer does, however, flag possible traces of egg, milk and fish linked to manufacturing.

Where to buy IO Genix Magnesium Citrate?

The 60-tablet bottle can be ordered from this page, and we ship anywhere in France and Europe. One bottle covers a full month's course, which makes it one of the simplest ways to secure a magnesium intake.

At the Vendargues counter, about ten minutes from Montpellier, the question we always ask in this section is not remotely technical: how is your transit? That is what decides between a citrate and a bisglycinate, far more than any absorption argument. The rest of the minerals can be browsed in our sports nutrition section.