INSYGMA NUTRITIONProduct science / Magnesium
Magnesium · bisglycinate and other oral forms
The science of magnesium
What the studies measured and what they found.
Randomized trials only
In the trials: fewer depression symptoms, relief from constipation and slightly less pre-eclampsia.
People who eat more magnesium-rich foods also tend to have other healthy habits. To find out what the supplement does, the only useful studies are those in which chance decides who takes magnesium and who takes an identical capsule without magnesium. This page counts only those, with magnesium taken by mouth.
- 3 of 34
- benefits graded A or B
- 21 of 34
- results with no clear effect or with varied results
What is best confirmed
- BGood results Fewer depression symptoms In 6 small trials, in people with depression Large decrease
- BGood results Relief from constipation In the 3 placebo-controlled trials About 7 in 10 improved
- BGood results Less pre-eclampsia In pregnant women, especially those at risk About 24% lower
Magnesium / Evidence in humans
How to read the grades, arrows and counts
The arrow shows the direction of the measure: down when the measure fell, for example blood pressure. It turns green when the change is an improvement. When the size was assessed, 1, 2 or 3 filled arrows mean a small, moderate or large effect. The = sign means no clear difference.
Few studies: only 1 or 2 controlled trials measured this result. Mixed results: the trials disagree.
When sorting by effect, the result with the largest magnitude in each topic counts. In a tie, the better grade of that result counts first, then alphabetical order. “Largest improvement with magnesium” considers benefits in comparisons where the effect of magnesium can be isolated. “Largest measured effect” also includes markers and combined treatments.
The grade says how well it works: A, it works and is well studied; B, good results; C, few studies (only 1 or 2 controlled trials measured this result) or mixed results (the trials disagree); D, no clear effect. For safety, A and B mean it does not increase risk, C that there are doubts and F that it increases risk. The grade comes from fixed rules: the size of the effect in the main review, the number of trials and people, and the agreement between trials.
The three arrows point in the direction of the measure. For example, a shorter walking time points down. When the record documents the magnitude, one, two or three dark arrows correspond to a small, moderate or large effect. For other changes, one dark arrow shows only the direction. For standardized mean differences, the descriptive benchmarks are 0.2, 0.5 and 0.8 in absolute value.
The = sign means the test did not detect a difference. “Varied results” means the results diverged between studies, tests or time points. For case reports, the table states what was observed. The counts are of publications; one trial can give rise to several articles.
The records summarize each published article, some from the full text and others from the abstract only. This is a targeted selection of up to 150 publications, not a new systematic review. Of the 134 study entries in the results (one study can appear in more than one), 131 come from fixed rules: the largest trials for each result, one publication per trial, and trials with 1,000 or more people. The other 3 are recorded exceptions: 3 studies cited in the summary.
| Topic | Measured result | Grade | Effect | Evidence |
|---|
Magnesium and kidney diseaseKidneys that work poorly People with kidney disease should talk to their doctor first See details
Why do the kidneys matter?
Extra magnesium leaves the body in urine. When the kidneys work poorly, it can build up.
In a trial with 148 patients with advanced chronic kidney disease, there were more bowel complaints with magnesium (35 versus 9) and more deaths and heart events (5 deaths and 6 events, versus 2 deaths and no events). The trial was too small to draw conclusions about these risks. There are also isolated case reports of very high blood magnesium in people with poorly working kidneys or a sluggish bowel who were taking magnesium oxide; they show what can happen, not how often. People with kidney disease should talk to their doctor before taking magnesium.
See the safety studiesMagnesium and the bowelDiarrhea and loose stools Mild complaints; if they bother you, ask about the dose See details
What was seen in the trials?
In the Cochrane review on cramps, mild complaints, mainly bowel-related (such as diarrhea), were slightly more frequent with magnesium: in 11% to 37% of those who took magnesium, versus 10% to 14% without magnesium. The difference was borderline and not clear. There was also no difference in serious effects or dropouts. If diarrhea bothers you, talk to your pharmacist or doctor about the dose.
The same effect explains why magnesium oxide helps with constipation: in 2 trials in adults, about 7 in 10 improved, versus 1 to 3 in 10 without magnesium.
See the safety studiesBisglycinate, citrate or oxide?The form of magnesium Oxide is absorbed less well See details
Is one form better absorbed?
There is no review of trials alone. In 46 healthy people, citrate and amino acid chelate were absorbed better than oxide, which was no different from the tablet without magnesium. In 12 patients missing part of their bowel, diglycinate (another name for the product's bisglycinate) was absorbed like oxide overall, but about twice as well in the 4 who absorbed oxide less well, and it was better tolerated. With oxide, a larger dose did not increase absorption in the same proportion.
See the studies on the formsWhat dose did the trials use?Compared with the product Close to the product's dose See details
How much magnesium a day?
- Product
- 200 to 300 mg
- Blood pressure (median)
- 365 mg
In the 38 blood pressure trials, the median dose was 365 mg of magnesium a day. In the bisglycinate sleep trial it was 250 mg a day; in the trial on absorption of the forms, 300 mg. In migraine, the trials used more: 600 mg a day. INSYGMA Magnesium Bisglycinate provides 200 mg with 2 capsules and 300 mg with 3.
See the blood pressure studiesFrequently Asked Questions
Does it lower blood pressure?
A little: about 3 mmHg.
In 38 trials with 2,709 people, systolic blood pressure fell by about 3 mmHg with magnesium. The decrease was larger in people already taking blood pressure medicines or with low magnesium; with normal blood pressure, almost none. Results varied a lot from trial to trial.
See the blood pressure studiesDoes it help you sleep?
A little, in some trials.
In 155 adults who slept poorly, magnesium bisglycinate, the form in the product, lowered insomnia severity a little more than without magnesium after 4 weeks. In a 2026 review of 12 trials, results varied from trial to trial.
See the sleep studiesDoes it stop leg cramps?
In most trials, no.
In the trials with oral magnesium in adults, most saw no fewer cramps; one saw fewer cramps only after 2 months. In pregnant women, the 4 trials taken together also saw no difference.
See the cramp studiesDoes it help with depression?
Symptoms fell a lot.
In 6 small trials with oral magnesium in adults with depression, symptoms fell much more with magnesium, but not all the trials agree. For anxiety and stress there are only 2 trials, very different from each other.
See the mood studiesIs it safe?
Yes.
Magnesium is a mineral found in food. In the trials, the most common side effect was mild bowel complaints, such as diarrhea, slightly more frequent than without magnesium, but with no clear difference. People with kidney disease should talk to their doctor before taking it: extra magnesium leaves the body in urine and, with poorly working kidneys, it can build up. In pregnancy, talk to your doctor too: in one large trial there were more baby deaths in the magnesium group, with no proof that magnesium was the cause.
See what is knownINSYGMA Labs · 11 November 2026 · Back to top ↑