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magnesium citrate

What is magnesium citrate? Your solution to constipation in 2022

02 Mar 2022 • 2 min read


Magnesium is a mineral that supports us in the process of turning food into energy and helps us to produce hormones that aid healthy bones, and it’s found in foods like spinach, nuts, and wholemeal bread.1

Magnesium citrate, however, has a very specific purpose—as a natural relief for constipation.

We’ll tell you all about how magnesium citrate works, how much you can safely take, and whether there are any side effects you should be aware of…

Just keep reading!

What is magnesium citrate?

Magnesium citrate is a combination of magnesium, salt, and citric acid—also known as a “saline laxative” as it’s so effective in relieving constipation and helping to clear out the intestines.2

Handpicked content: Why We Need Magnesium

What does magnesium citrate do for the body?

There are a number of magnesium citrate benefits for the body, most of which revolve around your intestines.

For example, before surgery or bowel procedures, such as colonoscopies or radiography, many doctors recommend a magnesium citrate dosage for bowel cleansing.

This helps to remove any stool from your intestines, giving experts a clean and clear view of your intestines.

In the same way, magnesium citrate constipation relief is often used. How does it work? Well, magnesium citrate increases water in the intestines which supports the passing of stool.

However, the magnesium citrate laxative effect is quite strong, and although a natural alternative, it is recommended that you begin with milder options such as stool softeners and bulk-forming laxatives before trying a magnesium citrate solution.

How do I get magnesium citrate in my diet?

Magnesium citrate comes in many different forms, making it easy to consume when and how you need to:

  • Magnesium citrate supplements
  • Magnesium citrate tablets
  • Magnesium citrate liquid
  • Magnesium powder

We’ll tell you about three of our favourite products soon, but first, let’s quickly discuss some rules around taking magnesium citrate:

  • Take magnesium citrate on an empty stomach (usually 1 hour before eating, or 2 hours after eating).
  • It’s recommended to drink a full glass of water after taking magnesium citrate as this may lessen the potential side effects, such as dehydration.
  • Follow the directions of your doctor or chosen product exactly, including dosage and duration of usage.
  • Only use magnesium citrate at the advice of your doctor and after checking the potential side effects—we cover these further below!

Handpicked content: 8 Of The Best Magnesium Supplements


  • Magnesium is a mineral that helps us to turn food into energy and supports healthy bones.
  • Magnesium citrate is a combination of magnesium, salt, and citric acid.
  • The main use of magnesium citrate is to clear the bowels before certain procedures and as a natural form of constipation relief since it increases water in the intestines.
  • It is recommended to try stool softeners or bulk-forming laxatives before magnesium citrate as they are weaker solutions that may work for you.
  • Magnesium citrate is available as supplements, tablets, liquid, and powder, but should only be taken at the advice of your doctor after understanding the possible side effects.

5 of the best forms of magnesium

Magnesium is certainly a hard-working mineral. But what are the best forms of magnesium? And why might you need more of it.

Magnesium citrate for constipation: Why does it work?

We’ve been talking about magnesium citrate as a potential solution for helping relieve constipation, but how does it actually work?

Well, magnesium citrate is something called an “osmotic laxative,” meaning it helps your bowels to relax while drawing more water in your intestines. This water then helps to soften and bulk your stool together, linked to easier bowel movements.

How much magnesium citrate should you take?

The correct magnesium citrate dosage is important and varies based on your needs, age, and response to treatment. The recommended dosages for constipation by age are:

Below 6 years: 0.5ml, orally, up to a maximum of 200ml. At the advice of a doctor.

6 to 12 years: 100-150ml, orally, one time.

Adults: 240ml, orally, one time.

Is it safe to take magnesium citrate daily?

As magnesium citrate is quite a strong, albeit natural, solution to constipation, it is not advised to take it daily.

If magnesium citrate is taken too often, it may adversely affect your normal bowel function and even leave you with a laxative dependence. This means that you would have difficulty having a bowel movement without the use of a laxative.

Symptoms of overuse include:

  • Abdominal pain
  • Diarrhoea
  • Weight loss
  • Weakness

If you experience any of these symptoms, it is advised that you consult with your doctor as soon as possible.

How long does it take for magnesium citrate to take effect?

It varies by person and dosage, but you should normally see the effects of magnesium citrate between 30 minutes and 6 hours. We’d recommend staying close to home—or a bathroom—while you’re waiting!


  • Magnesium citrate works as an “osmotic laxative,” helping to relax your bowels and bring more water into your intestines, useful for softening and bulking stool for easier bowel movements.
  • The correct magnesium citrate dosage varies by age and condition:
  • Below 6 years: 0.5ml, orally, up to a maximum of 200ml (with doctor supervision).
  • 6 to 12 years: 100-150ml, orally, one time.
  • Adults: 240ml, orally, one time.
  • Magnesium citrate takes between 30 minutes and 6 hours to show effects.

Are there side effects of magnesium citrate?

Magnesium citrate is believed to be safe for most people, however, as it is quite a strong solution for constipation, it can be linked with side effects like diarrhoea, stomach discomfort, and dehydration as more water is being passed through your intestines.

More serious side effects may also include:

  • Severe diarrhoea
  • Blood in stool
  • Sweating
  • Severe stomach pain
  • Dizziness
  • Fainting
  • Weakness
  • Allergic reactions, which could appear as hives, breathing difficulties, low blood pressure, or an irregular heartbeat.

If you do experience any of the serious side effects above, it’s advised that you stop taking magnesium citrate and contact your doctor immediately.

Is magnesium citrate suitable for everyone?

When used at the advice of a medical profession and in the correct dosage, magnesium citrate is safe for most people.

However, if you have certain conditions or issues prior to taking a magnesium citrate supplement, you should speak to a doctor for confirmation. These include:

  • Kidney disease
  • Existing stomach pain
  • Nausea or vomiting
  • Magnesium or sodium-restricted diet.
  • Changes in bowel movement habits that have lasted over 1 week

There have also been cases where magnesium citrate may reduce or stop the effects of other medications.

For example, the effectiveness of medications related to HIV may be affected or reduced when also taking magnesium citrate.

Magnesium citrate: The takeaway

Wow, we learned a lot today!

As you can see, magnesium does a lot for our body, supporting us in creating energy from the food we eat, healthy bones, and strong teeth.

When combined with salt and citric acid, it becomes magnesium citrate, helping to relieve constipation.

Then, there are even magnesium citrate supplements which help you to get your recommended daily intake of magnesium without inducing bowel movements. It really can do it all.

For more on magnesium, read about “Why We Need Magnesium,” “The Best Forms Of Magnesium,” and “8 Of The Best Magnesium Supplements” available at Holland & Barrett.

The advice in this article is for information only and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Last updated: 2 March 2022



Author: Bhupesh PanchalSenior Regulatory Affairs Associate

Joined Holland & Barrett: Apr 2019

Masters Degree in Toxicology and BSc Hons in Medical Biochemistry

Bhupesh started his career as a Clinical Toxicologist for Public Health England, advising healthcare professionals all around the country on how to manage clinical cases of adverse exposure to supplements, pharmaceuticals, cosmetics, industrial chemicals and agricultural products.

After 7 years in this role and a further year working as a drug safety officer in the pharmaceutical industry, Bhupesh joined Holland & Barrett as a Senior Regulatory Affairs Associate in 2019.

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