Magnesium for Anxiety: Does It Help? Best Type, Dose and What the Research Shows

Does magnesium help anxiety? The research

Magnesium is a hugely popular supplement for anxiety, and social media makes it sound like a sure thing. The studies are much more modest. Here is what the main reviews and trials found, in plain terms.

So the honest summary is: the research hints at a small benefit for some people, particularly those low in magnesium, but magnesium hasn’t been shown to treat anxiety disorders. We’d treat it as one small piece of a bigger plan, not the plan itself. If PMS is part of the picture for you, see magnesium for PMS.

Why magnesium is linked with stress

Magnesium is involved in nerve signalling and the body’s stress response. Magnesium contributes to normal functioning of the nervous system and to normal psychological function, which is why it comes up so often in conversations about stress.

Researchers have described a possible “vicious circle”: stress may increase the magnesium you lose, and low magnesium may in turn make the body more reactive to stress. Several studies have found lower magnesium status in people under psychological stress. It’s an interesting idea, but most of the evidence comes from lab and observational work, and several authors of the main review work for a supplement company. It hasn’t been proven that topping up magnesium reduces anxiety for most people.

If you’re wondering whether you’re low, see signs of magnesium deficiency. Food is the first place to look: leafy greens, nuts, seeds, beans and wholegrains are all good sources, and our list of foods high in magnesium has amounts per portion.

Best magnesium for anxiety: which form?

No form of magnesium has been proven best for anxiety, and the trials above used several different ones. What really differs between forms is how well they’re absorbed and how kind they are to your stomach.

For most people, glycinate is a sensible place to start simply because it’s gentle and easy to take every day. If you want the full side-by-side, our guide to magnesium glycinate vs citrate vs threonate goes into absorption and cost, and types of magnesium covers the less common forms.

Our Magnesium Glycinate Sleep Complex combines magnesium bisglycinate and magnesium citrate with glycine, L-theanine, chamomile, passionflower, hops and oat straw, giving 290mg of magnesium per serving as a berry-flavoured evening drink. It isn’t a treatment for anxiety. Magnesium contributes to normal psychological function.

How much magnesium for anxiety, and when

• Daily need: the NHS says adults aged 19 to 64 need 300mg a day (men) or 270mg a day (women), and most people can get this from food.
• Supplements: the NHS says 400mg or less a day from supplements is unlikely to cause harm. The anxiety and stress trials above mostly used around 200 to 300mg a day.
• Timing: many people take it in the evening as part of a wind-down. Splitting it between morning and evening also works. See best time to take magnesium.
• How long: give it four to six weeks of daily use before deciding. In the 2017 depression trial, changes showed up within two weeks. See how long magnesium takes to work.

More isn’t better. The NHS says high doses (more than 400mg) can cause diarrhoea, and there’s no evidence that a bigger dose will make you calmer.

Magnesium with L-theanine or vitamin B6

L-theanine is an amino acid found in tea, and it’s often paired with magnesium in evening blends, including ours. We’d love to tell you the combination is proven. It isn’t.

• L-theanine on its own: a 2026 meta-analysis of 31 placebo-controlled trials found a modest drop in acute stress, mostly from studies at high risk of bias. Effects on anxiety were inconsistent and not statistically significant. More in our L-theanine benefits guide.
• Magnesium plus L-theanine: we couldn’t find a human trial testing just these two together for anxiety. The nearest is a 2022 placebo-controlled trial of 100 stressed adults using magnesium, B vitamins, rhodiola and green tea (L-theanine), which found a small fall in stress scores after 28 days. With five ingredients, you can’t tell which did what, and several of the authors worked for the product’s maker.
• Magnesium plus vitamin B6: in the 2018 trial above, adding B6 did no better than magnesium alone overall, though it did a little better in the most stressed group.

People also pair magnesium with glycine (see glycine for sleep) or with herbs like ashwagandha. If you’re choosing between those two, our ashwagandha vs magnesium comparison sets out the evidence for each.

Panic attacks and palpitations

“Magnesium for anxiety and heart palpitations” and “magnesium for panic attacks” are big searches, so it’s worth being straight: we haven’t found any good trials of magnesium for either. The 2017 review’s studies were in people with mild anxiety, PMS, new mothers and people with high blood pressure, not panic disorder.

The NHS says palpitations are common and not usually serious, and stress, anxiety, caffeine, alcohol and lack of sleep are among the usual causes. See a GP if they keep coming back, last more than a few minutes or you have a heart condition. Call 999 if you have palpitations with chest pain, shortness of breath or fainting.

For in-the-moment help, see how to stop a panic attack, box breathing and heart palpitations at night.

Magnesium and low mood

Anxiety and low mood often travel together. In the 2017 trial above, depression scores improved within two weeks, but with no placebo group the result needs confirming. A 2023 meta-analysis of seven placebo-controlled trials (325 adults with depression) found lower depression scores with magnesium, and its authors also asked for bigger, better trials.

iIf you’re feeling low most days for more than two weeks, speak to your GP. Don’t stop or change antidepressants without medical advice. For a comparison with another popular option, see CBD and depression.

Side effects and who should check first

• Stomach upset: diarrhoea and cramps, mainly with citrate and oxide or doses over 400mg. Lower the dose or switch to glycinate.
• Kidney problems: speak to your GP before taking magnesium.
• Medicines: magnesium can affect how well some antibiotics and osteoporosis medicines, such as alendronic acid, are absorbed, so they need spacing apart. Ask a pharmacist how long to leave.
• Prescribed anxiety or depression medicines: tell your GP or pharmacist about any supplement you take. NICE asks doctors to talk through over-the-counter remedies with people who have generalised anxiety, because of possible interactions and limited safety evidence.
• Pregnancy and breastfeeding: we don’t recommend our products during pregnancy or breastfeeding. See magnesium in pregnancy and speak to your midwife or GP.
• Adults only: our products are for adults (18+). If a child or teenager is anxious, talk to your GP.

More detail in magnesium side effects.

What the NHS recommends for anxiety

The NHS doesn’t list magnesium or any other supplement as a treatment for anxiety. NICE guidance for generalised anxiety disorder (GAD) uses a stepped approach: start with the least intrusive thing that’s likely to work, and step up if it doesn’t.

• Self-help: NHS-recommended self-help books, online tools and courses, breathing exercises, yoga or pilates, regular exercise, enough sleep and a healthy diet.
• Cut back on the things that feed it: large amounts of caffeine, and using alcohol, cigarettes or drugs to cope. See does caffeine cause anxiety?
• Talking therapies: usually CBT. If you’re 18 or over and registered with a GP in England, you can refer yourself to NHS Talking Therapies without seeing a GP first.
• Medicines: where needed, usually a type of antidepressant called an SSRI, from your GP.

Our how to deal with anxiety guide puts these into a day-to-day plan, and anxiety symptoms helps you make sense of what you’re feeling. Other supplements people try are covered in best natural supplements for anxiety and CBD for anxiety.

Related guides

• Comparing options? See the best CBD oil for anxiety in the UK.
• Magnesium for sleep: what the trials show, the best type and how much to take.
• If you’re weighing up herbs too, see ashwagandha for anxiety: research, dose and safety.
• For non-supplement ways to calm a racing mind in bed, see anxiety at night and sleep anxiety.
• Which magnesium is best for stress, sleep and everyday use.
• Mushrooms for anxiety: what the evidence shows.
• Supplements marketed for stress, like GLOV Magnesium Complex, are worth reading against the GB register of authorised claims.