Magnesium For Irritable Uterus


Magnesium is a very important nutrient required for various bodily functions such as the regulation of blood pressure, blood sugar levels, bone health and protein production. The NHS recommended a daily doses of magnesium are as follows:

GenderDose (mg)
People assigned male at birth (PAMAB)300
People assigned female at birth (PAFAB)270

However, due to our busy lives it is not always possible to maintain the recommended magnesium levels our body needs. Magnesium rich foods and supplementations are therefore recommended. 

There are many different food sources that contain magnesium such as green leafy vegetables, fish, nuts, wholegrains and beef. There are also a wide range of magnesium supplements available and the most popular forms are magnesium citrate, magnesium hydroxide and magnesium sulphate amongst many others.

Magnesium citrate, which is created by mixing salt and citric acid, can help to relieve constipation due to its ability to empty out the intestines. Magnesium hydroxide has a similar effect to magnesium citrate as it can cause bowel movements but it has also been found to soothe heartburn and indigestion. Magnesium sulphate on the other hand has been found to reduce uterine contractions and is often prescribed to relieve an irritable uterus.1 Moreover, studies have found magnesium supplementation in women to be particularly important as it can help relieve symptoms associated with premenstrual syndrome (PMS), endometriosis and polycystic ovarian syndrome (PCOS).2 Thus, there are many benefits associated with magnesium supplementations. 

How does magnesium affect an irritable uterus?

An irritable uterus, which is common in pregnancy and may feel like braxton hicks, occurs when you experience mild contractions that are more frequent than braxton hicks  and may feel more powerful and painful. These contractions can often mimic cramps you would feel during menstruation and some women may also feel  tightening around the abdomen area. Although an irritable uterus may feel harmful and scary, there is no significant risk and magnesium supplementations have also been found to have positive effects on managing symptoms. There are also no known causes for irritable uterus however it is important to make your doctor aware and you should seek medical advice if symptoms worsen and your contractions are more painful than normal. 

The myometrium, which is the smooth muscle tissue of the uterus, can go through many physiological changes during its lifespan, i.e. contractions. These changes are vital for the uterus to function adequately and magnesium has been found to have positive effects on the myometrium and uterine activities.3 This is because magnesium reduces the entry of  calcium into the myometrium, which in turn reduces contractions of the myometrial smooth muscle wall thus reducing uterine contractions.1 

Although a majority of pregnant women do not fulfil the daily requirement for magnesium, the need for magnesium increases throughout pregnancy. Studies have also found a shortage in magnesium may also raise health risks for both mother and child which can include preterm labour, preeclampsia and gestational diabetes.4 Magnesium has also been found to help with insomnia which is helpful if you are unable to sleep due to anxiety or stress during pregnancy. Thus, pregnant women are encouraged to ensure they are maintaining a magnesium rich diet as well as taking supplementations to increase their magnesium levels. 

Which magnesium is best for an irritable uterus?

Taking magnesium has been known to reduce complications associated with pregnancy and studies have also found magnesium to be effective from keeping preeclamptic women from developing preeclampsia as well as preventing infant mortality.2

Magnesium can also;

  • Reduce the risk of osteoporosis 
  • Help with nausea 
  • Reduce uterine cramps and contractions
  • Treat insomnia
  • Lower the risk of preterm labour

Magnesium Sulphate has been known to calm and relax the uterus muscles during contractions and is widely recommended to help with an irritable uterus. Magnesium sulphate is also administered to women going through preterm labour to allow for the protection of the unborn child's nervous system.

Magnesium gluconate can be used to increase low magnesium levels in the blood but there are no known studies that show its effect on an irritable uterus. However, it is still recommended to take magnesium gluconate as it increases overall magnesium levels in the blood which is beneficial to overall health and wellbeing. This in turn shows the many benefits of magnesium for pregnancy and not just for the treatment of an irritable uterus. 

Magnesium oxide is a supplement that can be taken to treat magnesium deficiency  and is used to treat constipation and headaches and is recommended for pregnant and breastfeeding women. Magnesium oxide can also help with PMS as well as preeclampsia. It is not known whether magnesium oxide can directly treat irritable uterus but it is safe to take during pregnancy and allows for pregnant people  to meet their recommended magnesium intake. 

How much magnesium should I take for an irritable uterus?

The recommended dose for magnesium sulphate is based on an individual person's needs and therefore should be consulted with a doctor before using. 

The recommended daily dose for magnesium gluconate for pregnant people is as follows:

Age rangeDose (mg)
Over 30310

When breastfeeding, it is recommended to take 320 mg of magnesium gluconate daily. 

The recommended daily dose of magnesium oxide dose for pregnant people is as follows:

Age rangeDose (mg)
Over 31360

The recommended dosages are a guide and it is important that you do not exceed the recommended dosages as this could lead to magnesium toxicity so it is crucial to remain cautious and seek advice if you are unsure about how much magnesium is right for you. 

Side effects and other concerns

Magnesium sulphate may cause some complications amongst expecting mothers include:

There may also be some side effects of magnesium sulphate amongst the foetus which may include: 

  • Reduced muscle tone
  • Lethargy 
  • Hypocalcaemia(low calcium levels in the blood) 
  • Osteopenia 

It is worth noting that the NHS state that not all PAFAB  may be the best candidate for magnesium sulphate and it may only be offered to PAFAB  who are between 24-30 weeks pregnant and are at risk of preterm labour. Thus, taking magnesium in other forms may be recommended instead. 

There are no known side effects in unborn babies however some side effects of magnesium gluconate in pregnant women include: 

  • Vomiting
  • Nausea
  • Diarrhoea
  • Upset stomach
  • Bloating 

Some side effects of magnesium oxide can include: 

  • Upset stomach
  • Nausea 
  • Diarrhoea 
  • Gastrointestinal irritation 

It is important to note that magnesium may interfere with other drugs and should therefore not be taken at the same time as other drugs as they may disturb the absorbance of drugs and prevent medication from working effectively. The BNF has listed 24 interactions with magnesium. 


Magnesium deficiency during pregnancy may be very harmful to both mother and child and women are advised to increase their diet of foods high in magnesium, such as nuts, seeds and leafy greens, as well as to take a safe amount of magnesium supplements at their recommended dosages.6 Magnesium supplementations can also be found off the counter and are easily available which makes it easier to maintain a good level of magnesium and avoid magnesium deficiency. 

Magnesium can help relieve symptoms of an irritable uterus and is recommended by healthcare practitioners, however magnesium supplementations should be taken with care due to the side effects they may cause. Lastly, although an irritable uterus may cause more stress and anxiety on top of an overwhelming pregnancy, it is unlikely to lead to something serious. But, nevertheless, it is still important to speak to a doctor about your symptoms and enquire about magnesium supplementations. 


  1. Yildirim E, Macun HC, Cinar M, Yiğit AA, Ustüner I, Aydos TR, et al. The effects of magnesium sulphate on the contractile activity of uterus in an animal model of preeclampsia. Clin Exp Obstet Gynecol [Internet]. 2014;41(2):169–73. Available from:
  2. Porri D, Biesalski HK, Limitone A, Bertuzzo L, Cena H. Effect of magnesium supplementation on women’s health and well-being. NFS Journal [Internet]. 2021 Jun 1 [cited 2023 Aug 1];23:30–6. Available from:
  3. Uberti F, Morsanuto V, Ruga S, Galla R, Farghali M, Notte F, et al. Study of magnesium formulations on intestinal cells to influence myometrium cell relaxation. Nutrients [Internet]. 2020 Feb 22 [cited 2023 Aug 1];12(2):573. Available from:
  4. Fanni D, Gerosa C, Nurchi VM, Manchia M, Saba L, Coghe F, et al. The role of magnesium in pregnancy and in fetal programming of adult diseases. Biol Trace Elem Res [Internet]. 2021 [cited 2023 Aug 1];199(10):3647–57. Available from:
  5. Zhang H, Cao Y, Man Q, Li Y, Jia S, Wang R, et al. Magnesium nutritional status, risk factors, and the associations with glucose parameters of childbearing women in the china adult chronic disease and nutrition surveillance(2015). Nutrients [Internet]. 2022 Feb 17 [cited 2023 Aug 1];14(4):847. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Sabiya Ali

BSc Pharmacy Science and Health University of the West of Scotland

Hi, my name is Sabiya and I am currently a recent graduate. I am passionate about science and particularly interested in women's health. I enjoy researching and writing articles which is why I decided to work for Klarity's public health library. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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