The side effects of magnesium at a glance

Die Nebenwirkungen von Magnesium im Überblick

Are you considering taking supplemental magnesium supplements, but are concerned about the side effects? Would you like to learn more about the mineral and the possible side effects? Then you are exactly right here.

This article is intended to give you an understanding of the essential functions of magnesium and the possible side effects of inappropriate intake. We have also summarized valuable tips for you on the right magnesium intake and measures to be taken in the event of side effects.

the essentials in brief

  • Excessive intake of magnesium supplements can lead to hypermagnesemia. The magnesium overdose is usually harmless, since the body regulates the magnesium balance itself by excreting liquid.
  • The side effects of an overdose include diarrhea, gastrointestinal problems, drop in blood pressure, paralysis, muscle weakness, cardiac arrhythmia and cardiac arrest.
  • A magnesium deficiency is accompanied by symptoms such as cramps, overstimulation of the muscles, falling body temperature, fatigue, calcification of the blood vessels and kidneys and a disorder of the cardiovascular system.

Magnesium side effects: What you should know about them

Magnesium should not be taken without hesitation and in uncontrolled amounts. Undesirable side effects can be the result of incorrectly dosed magnesium intake. In order to avoid side effects, we have summarized the most important information for you here.

What is magnesium?

Magnesium is one of the electrolytes in the body. The mineral is involved in more than 600 processes in the body and is therefore vital. Some of the most important features are:

  • Reduction of tiredness and fatigue
  • electrolyte balance
  • energy metabolism
  • nerve function
  • muscle function
  • protein synthesis
  • cell division

These are just a few of magnesium's functions, but as you can already see, this mineral is essential to life. The element magnesium is not only an important nutrient for the human body, it is also found in nature in soil, rocks and seawater.(1)

Since the body cannot produce magnesium itself, it must be ingested through food. Wholemeal bread, broccoli, bananas and nuts are particularly magnesium-rich foods.

Nevertheless, it can happen that people suffer from a magnesium deficiency. Then the magnesium supply via supplementary preparations is necessary.

What is the best way to consume magnesium?

Magnesium is better absorbed when consumed in smaller amounts throughout the day rather than all at once in one large portion.

The transport system that transports magnesium into the body can only absorb minerals to a limited extent. If too much magnesium is taken in at once, only part of it can be utilized. (12)

When taking it, you should also pay attention to which magnesium you are taking, because not all magnesium is the same. It occurs in organic and inorganic compounds:

Connection magnesium function
organic magnesium citrate against constipation and kidney stones
organic magnesium glycinate well tolerated, calms the stomach
organic magnesium aspartate Dietary supplement, low magnesium content
inorganic magnesium carbonate against heartburn, as sweat minimization in athletes, bulking agent
inorganic magnesium phosphate against menstrual cramps and muscle cramps
inorganic magnesium oxide Neutralizes acid in the stomach, laxative

The various forms of magnesium intake also differ. YOU can choose between powder, capsules, tablets and liquid.

What is the daily requirement of magnesium?

The daily requirement of magnesium depends on gender and age. Our table shows you the recommended amount of magnesium that you should consume daily. (2)

Old mg/day males mg/day women
Infants (0-12 months) about 24-60 mg/day about 24-60 mg/day
Children (1-10 years) about 80-170 mg/day about 80-170 mg/day
Children (10-15 years) about 230-310 mg/day about 250-310 mg/day
Adolescents and young adults (15-25 years) about 400 mg/day about 350-310 mg/day
Adults (25-65 and older) about 350 mg/day about 300 mg/day
pregnant women - about 310 mg/day
breastfeeding - about 390 mg/day

However, other factors also play a role in the correct dosage of magnesium. Certain groups of people should consume more magnesium than the recommended reference value. This includes:

  • competitive athlete
  • alcohol drinking
  • people under stress
  • People who are prone to palpitations
  • people who fast a lot

Athletes in particular have an increased need for magnesium, since the body loses a lot of magnesium through sweat. Alcohol drinkers also have an increased need for magnesium, as this is excreted to a greater extent through the alcohol.

What happens if you take in too much magnesium?

An overdose of magnesium leads to an excess in the blood. A so-called hypermagnesemia usually occurs in the context of severe kidney disease and can lead to the following side effects:(3)

  • Diarrhea
  • Gastrointestinal complaints
  • drop in blood pressure
  • signs of paralysis
  • muscle weakness
  • cardiac arrhythmias
  • cardiac arrest

An overdose of magnesium can have unpleasant consequences. The specific side effects that occur depend on the amount of the overdose. An additional magnesium intake of 300 mg per day can lead to diarrhea and gastrointestinal problems. Taking more than 2500 mg per day can even cause a drop in blood pressure or muscle weakness.

An excess of magnesium usually only occurs in combination with other diseases.

64% of dietary supplements containing magnesium contain more than the recommended maximum daily dose in dietary supplements. To avoid an overdose, you should therefore not take any magnesium supplements without consulting a doctor.(3)

What happens if you take in too little magnesium?

Consuming less than the recommended daily amount of magnesium over a long period of time can lead to reduced concentrations in the blood and thus to hypomagnesemia. The magnesium deficiency manifests itself as follows:(4)

  • cramps
  • muscle overstimulation
  • falling body temperature
  • fatigue
  • Calcification of the blood vessels and kidneys
  • Disorder of the cardiovascular system

Magnesium deficiency can occur even in infants. Symptoms such as failure to thrive, susceptibility to infection or seizures occur. In older children, a magnesium deficiency can lead to tiredness and poor concentration.

foods containing magnesium

Calcium and magnesium are antagonists in muscle function. In addition to foods that are particularly rich in magnesium, such as pumpkin seeds, you should also get enough calcium, for example from cow’s milk or leaf spinach. (Image source: unsplash / Maddi Bazzocco)

Girls tend to have late menstruation with cramping pains. In pregnant women, magnesium deficiency manifests itself through nausea, vomiting, water retention and high blood pressure.(5)

There are many causes of hypomagnesemia. Some of them are an unbalanced diet, an increased need due to sport, stress or pregnancy, but also alcoholism.

Can Too Much Magnesium Harm During Pregnancy?

Magnesium is a very important mineral during pregnancy. Pregnant women have an increased magnesium requirement of 310 mg per day because they have to take care of the baby. The embryo needs magnesium for growth processes, the formation of bones and for the development of a brain and nerve tracts.(6)

100 ml breast milk contains an average of 3 mg magnesium.

During pregnancy, a slightly increased magnesium intake of 310 mg per day is recommended, as hormonal changes during pregnancy mean that more magnesium is excreted in the urine. A magnesium intake of 390 mg per day is even recommended for breastfeeding mothers.

Caution is advised in the case of a very high and persistent magnesium deficiency. A magnesium deficiency can lead to delayed development of your baby or early labour.

The embryo stores up to 7 mg of magnesium in the growing bones and muscles in the last three months of pregnancy.(6)

You don't have to be afraid of overdosing. The body simply excretes excess magnesium. Typical side effects that occur in pregnant women when taking magnesium are:(5)

  • Diarrhea
  • fatigue
  • Muscle weakness of the baby with permanent magnesium overdose
  • poor absorption of iron
  • worse effect of antibiotics
  • pain in the nipples

What side effects can magnesium cause in children?

Daily magnesium intake is influenced by other factors in addition to age and gender. General condition and physical fitness also play an important role. A physically active 15-year-old needs more magnesium than a child of the same age who does little exercise.

child laughing

If you take magnesium in the form of supplements, make sure to take smaller amounts throughout the day. The body can use smaller doses better. (Image source: unsplash / Ben White)

A permanent magnesium deficiency should be prevented in any case, while a magnesium overdose is usually not dangerous and is also possible through food intake alone.

Side effects that occur with long-term overdose are the same as in adults.

  • increased nervousness
  • Stomach and intestinal problems
  • Diarrhea

The symptoms are similar to those of underdosing, which is why it can be problematic if you continue to take magnesium to compensate. In order to avoid risks, a doctor should always be consulted first.

What are the side effects of magnesium for my skin?

It is claimed that magnesium can negatively affect the skin's appearance and lead to pimples or breakouts. However, it is controversial that skin rashes can occur purely due to magnesium intake. Rashes are more likely to be triggered by additives in magnesium supplements.(7)

Bathing in a magnesium-enriched Dead Sea salt solution can improve skin barrier and hydration.(7)

Magnesium can also have a positive effect on the complexion. With a sufficient supply of magnesium, the mineral has an anti-inflammatory effect on skin rashes and accelerates the reconstruction of the skin barrier. A magnesium deficiency can worsen the complexion.(8)

Why do I get gas from magnesium?

Exceeding the recommended daily dose can quickly lead to gastrointestinal problems. Taking more than 250 mg of magnesium per day in supplement form can lead to diarrhea.(4)

The good news is that this side effect can be resolved quickly. A reduced dose of magnesium can make the unpleasant side effects subside within a day or two. It is not a health risk for healthy people with normal kidney function.

Can magnesium cause increased sweating?

Excessive sweating can lead to a magnesium deficiency. The increased production of sweat means that more minerals such as magnesium are excreted from the body. Often these individuals will exhibit other symptoms of magnesium deficiency.(9)

man jogging

At high temperatures and humidity, athletes can lose up to 2 liters of fluid per hour. In order to maintain muscle function, the magnesium and fluid loss should be quickly compensated. (Image source: unsplash/Jenny Hill)

Conversely, some research approaches see magnesium deficiency as the cause of increased sweating. However, there are not enough studies and evidence for this theory.

With the help of antiperspirants, sweat production can be curbed and a magnesium deficiency prevented. The astringent active ingredients constrict the sweat glands so that the escape of sweat is reduced or prevented.

Magnesium Side Effects: Proper Dosage and Approaches to Treating Side Effects

In order to avoid side effects from magnesium intake, you should pay attention to the correct dosage. We have summarized the most important information and what you can do if you still experience side effects below.

The right magnesium dosage

The correct magnesium dosage depends on age and gender, but is also influenced by other factors such as pregnancy, stress, exercise and sweating. We have put together an overview of the daily recommended amount of magnesium for you here.(2)

Old mg/day males mg/day women
Infants (0-12 months) about 24-60 mg/day about 24-60 mg/day
Children (1-10 years) about 80-170 mg/day about 80-170 mg/day
Children (10-15 years) about 230-310 mg/day about 250-310 mg/day
Adolescents and young adults (15-25 years) about 400 mg/day about 350-310 mg/day
Adults (25-65 and older) about 350 mg/day about 300 mg/day
pregnant women - about 310 mg/day
breastfeeding - about 390 mg/day

However, experts assume a higher magnesium requirement.(10)

  • Adults: In adults, magnesium researchers assume a requirement of 7-10 mg per kg of body weight. A person weighing 70 kg would then have a magnesium requirement of 500-700 mg per day.
  • Children and adolescents: According to experts, this group of people has an even higher magnesium requirement. The requirement is 15-30 mg per kg of body weight.

The requirement also increases when there are illnesses, during pregnancy, due to stress, heavy sweating or during sport. People who smoke or drink a lot of alcohol also need more magnesium.

An increased magnesium intake is usually harmless, since the body ensures a regulated magnesium balance by excreting urine. It can become problematic when taking high-dose preparations over a longer period of time. A magnesium deficiency can also be dangerous.

Measures for side effects caused by magnesium

Before combating the side effects, the cause of the side effect should first be addressed.

  • Magnesium excess: A magnesium excess is usually treated with diuretic drugs. You should also have the cause of the excess medically clarified. A disease such as kidney failure may have led to the excess.
  • Magnesium deficiency: A magnesium deficiency can be quickly remedied by taking supplements. The amount of magnesium to be taken should be discussed with a doctor beforehand.

Too high a dose of magnesium can lead to unpleasant side effects. We have summarized what you can do about it here.

  • Diarrhea: Too much magnesium can cause diarrhea. If you experience this side effect, you should stop taking magnesium. It shouldn't pose any additional health risks for people with healthy kidney function, but make sure you drink enough.
  • Drop in blood pressure: Magnesium can lower blood pressure. In the event of an overdose, this can lead to a drop in blood pressure. Meanwhile, some studies also indicate that magnesium can increase blood pressure. If you often feel weak after taking it, you should consult a doctor(11)
  • Signs of paralysis: In particularly serious cases, the nervous system can be affected. Magnesium then leads to symptoms of paralysis. You should stop taking magnesium immediately and also consult a doctor.

The symptoms of an overdose are often similar to those of a magnesium deficiency, which is why you should not make an ad hoc diagnosis if side effects occur. Consult a doctor first and how to proceed.


The side effects of magnesium are relatively manageable compared to other preparations. The risk of suffering from hypermagnesemia is also relatively low. A magnesium deficiency can be problematic. However, with a balanced diet, your daily magnesium requirement should be covered.

Nevertheless, magnesium is one of the essential minerals and the correct dosage of magnesium intake should not be underestimated. Because of the mild symptoms, it is often difficult to detect a magnesium overdose. If you are already experiencing the first signs of side effects or if you are generally unsure about taking magnesium, you should consult a doctor.


  1. Hermes Drugs GmbH., 2020
  2. German Nutrition Society, 2020
  3. Consumer Center, December 2016
  4. Office of Dietary Supplements, March 24, 2020
  5. Prof. Dr. Claudia Hellmers, Prof.Dr. Nicola Bauer, Journal of Midwifery Science, February 2014
  6. Spätling L., Classen H., Kisters K., Liebscher U., Rylander, Ragnar, Vierling, Wolfgang, Ehrlich, B., Vormann J., 2015, 56. 892-898.
  7. Ehrhardt Proksch, Hans‐Peter Nissen, Markus Bremgartner, Colin Urquhart, February 2, 2005
  8. Denda, M., Katagiri, C., Hirao, T. et al., 1999, Arch Dermatol Res 291, 560-563
  9. Yong-Mei Tang, Dao-Gang Wang, Jun Li, Xing-Hua Li, Qian Wang, Nan Liu, Wei-Tian Liu, Ying-Xue Li, May 2016
  10. K Kisters, HG Classen, J Vormann, T Werner, R Smetana, and O Micke, May 2020
  11. Zhang X, Li Y, Del Gobbo LC, et al. , 2016, 68(2):324-333.
  12. A. Berthelot, July 2, 2003, Switzerland Med Forum No. 27
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