Does magnesium glycinate help with depression? What the research does and doesn't show

The evidence doesn't support magnesium, in any form, as a treatment for depression — and the research is unusually inconsistent even by supplement standards. One open-label trial without a placebo group found a large improvement in mild-to-moderate symptoms. A broader systematic review found that effect shrinks dramatically once only placebo-controlled trials are counted. A newer meta-analysis of placebo-controlled trials found a large effect again.

What the evidence doesn't support

It doesn't support magnesium glycinate, or any other form of magnesium, as a treatment for clinical depression, major depressive disorder, or persistent low mood. It also doesn't resolve a genuine disagreement in the field: one systematic review found little evidence magnesium is involved in mood disorders at all once placebo effects are accounted for, while a more recent meta-analysis found a large, statistically significant benefit. No trial reviewed here isolated magnesium glycinate specifically, and none tested our elemental dose in that form.

What the trials found

The most-cited positive result is a 2017 open-label, randomized crossover trial in 112 adults (mean age 52) with mild-to-moderate depression. Participants took 248 mg/day of elemental magnesium as over-the-counter magnesium chloride for six weeks, compared to six weeks of no treatment. Depression scores improved by a net 6.0 points on the PHQ-9 and anxiety scores by 4.5 points on the GAD-7, both statistically significant, with effects showing up within two weeks and holding regardless of age, sex, baseline severity, or whether someone was also on an antidepressant. The important limitation: this trial had no placebo arm. It compared taking magnesium to taking nothing, which can't separate a real drug-like effect from the improvement people often report simply from starting something new and being monitored closely.

That limitation is exactly what a 2018 systematic review and meta-analysis went looking for. It found that magnesium supplementation trials without a placebo comparison showed a very large effect on depression scores (Hedge's g=-1.60), but trials that did include a placebo group showed a much smaller effect (g=-0.21) — a gap large enough that the authors concluded there is "little evidence for the involvement of Mg2+ in the mood disorders." The same review found a magnesium-rich diet was associated with less depression in cross-sectional surveys but not in studies that followed people over time, and that blood magnesium levels didn't track with how severe someone's symptoms were.

A 2023 meta-analysis then complicated that picture again. Pooling 7 placebo-controlled randomized trials (325 people total, ages 20-60), it found a large, statistically significant reduction in depression scores with magnesium versus placebo (standardized mean difference -0.919). That's a bigger effect than the 2018 review found in placebo-controlled trials generally, built from a small and only partly overlapping set of studies. The authors themselves called for larger, higher-quality trials before treating the finding as settled. Neither review reports the doses or forms used consistently enough to say what any specific dose or form would be expected to do.

Questions people ask

Does magnesium glycinate help with depression?

The research doesn't answer that directly. No trial has tested magnesium glycinate specifically, the closest dose-matched trial used magnesium chloride without a placebo group, and two systematic reviews of the broader literature reached different conclusions about how strong the effect even is once placebo response is accounted for.

Can magnesium glycinate cause depression?

None of the trials in the reviews above reported depression as a side effect of taking magnesium. Low magnesium status has been observed alongside depression in some studies, but that's a correlation in the data, not evidence that a normal magnesium intake prevents or that a low one causes depression.

What dose of magnesium glycinate is used for depression?

There isn't an established dose, because no trial has tested magnesium glycinate for depression at all. The one dose-matched trial (248 mg/day elemental) used magnesium chloride, and the systematic reviews above pooled a range of forms and doses without reporting one that stands out as the tested amount.

Is magnesium glycinate good for anxiety related to depression?

That's a related but separate question from the one this page covers. See our review of magnesium and anxiety for what that specific literature shows.

When to talk to a doctor

Persistent low mood, loss of interest in things you usually enjoy, or any thoughts of self-harm are reasons to talk to a doctor, not to shop for a supplement. Magnesium is not a treatment for depression, and nothing in the research above supports using it as a substitute for an evaluation, therapy, or medication a doctor might recommend. If you already take medication for depression or any other condition, or are pregnant or nursing, talk to a doctor before adding any supplement.

Related reading: magnesium and anxiety: what the research does and doesn't show and magnesium and stress: what the research does and doesn't show.