Magnesium is one of the body’s most important minerals, but many of us don’t get enough in our diets. One option is to take a magnesium supplement, but do they really work? What health benefits can you expect? And are those magnesium benefits supported by science? Read on for the answers!
What is magnesium?
Magnesium is a mineral. It’s one of 21 “essential” minerals you need for optimal health, and one of five extra-important minerals called electrolytes.
Magnesium is involved in more than 300 processes in the body, many of them critical for survival. These include:
- Muscle and nerve function
- Bone synthesis (creation)
- Blood sugar control
- Blood pressure regulation
- Heart rhythm
- Immune regulation
- Energy production
- DNA and RNA synthesis
- Protein synthesis
If you don’t get enough magnesium in the diet — and many of us don’t — then these critical processes will start to struggle. The worrying thing is that this can start to happen long before we ever get symptoms if we get them at all. This is called a subclinical deficiency, and it’s associated with cardiovascular disease and a long list of other health complications, like:
- Alzheimer’s disease
- High blood pressure
- Type 2 diabetes
What are the benefits of magnesium?
Reduction of Tiredness & Fatigue
Magnesium deficiency itself is a possible cause of low energy levels and fatigue. That’s because magnesium is an essential part of your body’s energy-making process. Here’s a (very simplified!) overview of how that works…
Your cells run primarily on energy from glucose. To extract that energy, glucose goes through a series of chemical reactions called the Krebs cycle. As the energy is released, it’s captured by a little molecule called ATP, which ferries the energy around the body and into your cells.
Here’s where magnesium comes in: your cells can’t actually use the energy unless it’s bound to magnesium. So if you’re not getting enough magnesium in your diet (or from supplements), your cells are essentially being starved of energy. That can translate to general feelings of fatigue and weakness.
Heart health and blood pressure
As an electrolyte, magnesium is essential for healthy heart function. As levels of magnesium drop, research suggests that the risk of heart problems like coronary heart disease and hypertension (high blood pressure) rises. On the contrary, higher magnesium levels are associated with a lower risk of heart disease and stroke.
Your blood lipid profile is made up of LDL cholesterol, HDL cholesterol, and triglycerides (fatty acids). Heart disease is associated with higher levels of “bad” LDL cholesterol and triglycerides, and lower levels of “good” HDL cholesterol. Magnesium supplements have been shown to promote the opposite, which is one possible explanation for its beneficial effects on the heart.
Two types of magnesium supplements in particular have shown promise in supporting good heart health. Magnesium orotate (magnesium and orotic acid) has been shown to repair injured cardiac muscle tissue and improve survival rates in those with congestive heart failure. Meanwhile, magnesium taurate features taurine, an amino acid crucial to heart health, and has been shown to reduce blood pressure and protect cardiac tissue in animal studies.
Magnesium’s positive effect on blood pressure — another major cardiac risk factor — has been shown in study after study after study. In one particular study, people who took magnesium chloride every day noticed a significant decrease in blood pressure. In another study, magnesium oxide was shown to have a similar effect. In fact, it’s been found that the higher the blood pressure, the greater the benefit.
Blood sugar control
Blood sugar (glucose) is regulated by a hormone called insulin, which helps the cells to take in glucose from the blood so that it can be turned into energy. If blood sugar is consistently too high, cells can become resistant/insensitive to insulin. Over time, this can develop into pre-diabetes, then type 2 diabetes.
Magnesium plays a major role in blood sugar regulation. So much so that research shows people with low magnesium intake have a significantly higher risk of developing diabetes. Further, insulin resistance causes excessive urination, and magnesium is lost in the urine. That means magnesium deficiency and insulin resistance can reinforce each other, potentially creating a vicious cycle that leads to diabetes.
On the other hand, one large study found that higher magnesium levels reduce the risk of pre-diabetes progressing to diabetes. Another found that, in those with the highest magnesium intake, diabetes was 47% less likely. This may be partly because magnesium has a very well-documented positive effect on blood sugar control and insulin sensitivity (as shown here, here, here, here, and here). Not only might that contribute to preventing diabetes, but it can also help people who already have diabetes to better manage the condition and reduce the risk of serious complications.
Anxiety and depression
Magnesium is involved in lots of biochemical reactions in the brain, many of which relate to mood and emotional regulation. For example, magnesium is needed to create serotonin, a neurotransmitter that plays a major role in mood, sleep, and mental health.
This may explain why people with depression or anxiety are generally found to have low magnesium levels. In an analysis of over 8,800 people, those with the lowest magnesium intake were found to have a 22% higher risk of depression. In an animal study, researchers were actually able to initiate anxiety by lowering magnesium intake.
Meanwhile, another study found that supplementing with magnesium actually improved the effectiveness of antidepressant medications. Not only do researchers think it may be a promising treatment option for clinical depression, it may also reverse neural damage caused by extended periods of stress.
When it comes to mood, two types of magnesium supplements stand out. Magnesium chloride has been found to improve symptoms of depression and anxiety when used alongside other treatments and has even been shown to be as effective as a common antidepressant for improving depressive symptoms.
In a review of patient case histories, researchers found that magnesium glycinate had helped to improve symptoms of mental illness like depression, anxiety, alcohol abuse, and drug addiction. In one famous case, a patient was reported to recover from major depression in just seven days with magnesium glycinate and magnesium taurate supplementation.
Of course, this is an extreme case and it goes without saying that you may not get the same results from supplements. And you absolutely shouldn’t use them as a replacement for mental health treatment. However, it does suggest that for some people, magnesium supplements may be an effective addition to a wider treatment plan.
Insomnia is connected to stress, low mood, and mental health difficulties. We know that glycine, the amino acid in magnesium glycinate, has a calming effect that can help to improve sleep quality. Together with magnesium, evidence shows that it improves aspects of sleep like:
- Sleep time.
- Sleep onset latency, or how quickly you fall asleep.
- Sleep efficiency, or the proportion of your time in bed that you spend asleep.
- Levels of melatonin and cortisol, are the two key hormones controlling the sleep-wake cycle.
Chronic pain is not very well understood and is notoriously difficult to treat, so sufferers often turn to supplements like magnesium to look for relief. For some conditions, like fibromyalgia, research seems to support this.
In one study, magnesium malate was shown to significantly improve the pain symptoms of people with fibromyalgia. In another, patients reported that their muscle pain had improved and they had fewer tender spots around the body after taking magnesium malate.
Magnesium chloride has also been shown to reduce muscle pain in conditions like fibromyalgia and even gave one 10-year-old boy complete relief from chronic muscle pain that had plagued his young life. It may also be helpful for those suffering from neuropathic pain (pain caused by nerve damage/dysfunction).
Female reproductive health
Magnesium has been found to offer benefits at every stage of a woman’s reproductive life. Low magnesium levels are associated with premenstrual syndrome, or PMS, which affects some women severely. Magnesium is shown to relieve PMS, especially when taken alongside vitamin B6. It can relieve the mood swings and depressive symptoms that sometimes come with PMS, and magnesium oxide specifically can help to reduce PMS-related fluid retention.
During pregnancy, magnesium glycinate is commonly used to relieve painful leg cramps (as shown here and here). It can also reduce the risk of premature labor and pre-eclampsia, a dangerous condition involving high blood pressure.
Among many more reported benefits for women, magnesium can reduce inflammation, hirsutism (excessive body hair growth), and cardiovascular risk factors in those with polycystic ovary syndrome (PCOS). It’s also been shown to ease the hot flashes, mood swings, and insomnia that often come with menopause, and to potentially reduce high blood pressure and bone density loss.
Certain forms of magnesium — most commonly citrate and oxide — are used to treat digestive and gastrointestinal problems. Magnesium citrate is a very effective laxative, relaxing the bowels and pulling water into the intestines to relieve constipation. Magnesium oxide, meanwhile, is the main ingredient in over-the-counter indigestion and heartburn remedies like Milk of Magnesia.
It’s worth noting that if you don’t have digestive problems, this laxative effect is more of a drawback than a benefit! In this case, it’s best to opt for magnesium malate, magnesium taurate, or magnesium glycinate instead. All have high bioavailability and are well-tolerated, and magnesium glycinate is known to be especially good for those with sensitive stomachs or digestive issues.
If you’ve ever suffered from migraines, you’ll know they can be pretty debilitating and hard to treat. There’s evidence that magnesium deficiency is much more common in people who suffer from migraines, and research does in fact show that magnesium supplementation can reduce the frequency and severity of attacks.
There’s lots of evidence for magnesium citrate, specifically. This study, this one, and this one all found that magnesium citrate reduced the frequency of migraine attacks, with the latter showing an impressive 41.6% reduction.
Magnesium oxide is effective against migraines too, with one study finding that children experienced fewer “headache days” after supplementation. And another form, magnesium sulfate, has been shown to be even more effective than a common migraine medication in quickly relieving active migraine attacks.
Magnesium in general is believed to boost overall brain health, but there’s one particular type that seems to stand out above the rest. Magnesium L-threonate (a compound of magnesium and threonic acid) is thought to cross the blood-brain barrier more easily than other types, leading to higher concentrations — and greater benefits — in the brain cells.
In an animal study, magnesium L-threonate improved various cognitive functions, like learning ability and multiple types of memory (long-term, short-term, and working). It may also be able to moderate the effects of cognitive aging and even restore memory deficits, keeping the brain in healthy working order for longer.
One explanation for these benefits is that magnesium L-threonate increases the number of stem cells in the hippocampus, an area of your brain that plays a big part in learning and memory. Stem cells are vital for the ongoing renewal and recovery of brain cells, so when it comes to cognitive health, the more the better!
The ancient Greeks and Romans believed that bathing in magnesium-rich water would soothe inflamed skin, ease aches, and pains, and rid the body of toxins. If you’ve ever been to a hot spring or soaked in an Epsom salt bath, you’ve carried on this tradition! But does it actually work?
When it comes to skin health, there is evidence that magnesium does in fact help. The symptoms of many skin conditions are caused by damage or dehydration in the skin’s natural protective barrier. Bath salts or lotions that contain magnesium chloride have been shown to help repair this barrier, provide extra hydration, and reduce inflammation and dryness.
Last but not least, magnesium may also help to improve exercise performance. Depending on the activity, your body needs up to 20% more magnesium during exercise. That magnesium helps to make more glucose available in the blood, move that glucose into your muscles, and clear out lactate (the stuff that builds up to cause muscle pain and fatigue).
It makes sense, then, that athletes are increasingly using magnesium supplements to boost their performance. One group of volleyball players found that their anaerobic metabolism and key movements were better after taking daily magnesium. Meanwhile, triathletes found that not only did magnesium orotate improve their performance in all three activities, but it also reduced insulin and stress hormone levels. And during exercise recovery, it seems that magnesium oxide can help to restore healthy blood pressure.
It’s not just athletes that may benefit from magnesium supplements. Elderly women who took magnesium oxide noticed improved exercise ability and performance. Patients with chronic obstructive pulmonary disease had improved lung function and exercise performance after taking magnesium, and patients with coronary artery disease had better cardiac function and exercise tolerance. That suggests that regardless of your age, health, or athletic abilities, magnesium may help you to reach your physical activity goals and improve your overall physical well-being.
What about side effects?
That’s an impressive list of potential benefits, but what’s the catch? What are the side effects and risks of taking magnesium supplements?
As with any supplement, people with existing health conditions should take extra care when considering magnesium supplements. They’re safe for most people, but they may not be suitable for people with kidney problems, for example. They can also interact with certain medications like diuretics, antibiotics, or heart medication. Always check with your doctor first!
For everyone else, if you take magnesium at the recommended dosage, you should experience very few side effects. The most common is digestive discomfort, in the form of stomach aches, nausea, and or diarrhea. This is most likely with magnesium oxide and citrate, and least likely with better-tolerated forms like taurate, glycinate, and malate. So if you have a delicate stomach, choose accordingly and keep your dosage on the lower side!
How much magnesium should I take?
Speaking of dosage, how much magnesium do you need? The National Institutes of Health recommends the following dosages:
|Birth to 6 months
Your supplement labels should tell you how much magnesium a dose contains, and also roughly how much of your daily needs it meets (look for the Nutrient Reference Value, or %NRV).
If you already get some magnesium from your diet, you might wonder what happens if your supplement takes you over and above your daily needs. It takes an incredibly high amount of magnesium to cause toxicity, and your body is good at filtering out excess magnesium in the urine. So as long as you stick to the recommended dosage, you don’t need to worry about taking too much!
Should I take a magnesium supplement?
Theoretically, you can get all the magnesium you need from your diet. However, experts agree that this is quite difficult these days due to soil contamination, poor soil quality, and excessive processing. These all deplete the actual magnesium content of our food, so even someone eating a supposedly magnesium-rich diet could be deficient. Other reasons for magnesium deficiency include stress, diabetes, heavy drinking, and certain medications.
It’s hard to know for sure if you have an actual magnesium deficiency. But if you don’t get much in your diet, you’re under a lot of stress, and/or you have a chronic health condition, chances are your levels might be low. Telltale signs of a magnesium deficiency include:
- Muscle cramps, stiffness, or spasms
- Eye twitches
- Headaches or migraines
- Numbness or tingling
- Irregular heartbeat or palpitations (a “fluttering” sensation in your chest)
- Anxiety, depression, or low mood
Read our article on how to test for magnesium deficiency at home.
In most cases, a magnesium supplement can help keep your magnesium levels topped up and fend off potential complications. Be sure to read our comparison of the different types of magnesium supplements.