How Long Does Magnesium Citrate Stay In Your System?

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    Magnesium Citrate is a magnesium supplement that is commonly used as a saline laxative. How long does it stay in your system? Find out here.

    What is magnesium citrate?

    Magnesium is an essential mineral that is required in the body for more than three-hundred processes. It is always best to try to get your nutrients from a healthy, well-balanced diet and magnesium can be found in dark leafy greens, milk, yogurt, Greek yogurt, dried beans, chickpeas, legumes, peanuts, almonds, and cashews. In the case of dietary insufficiencies or absorption issues resulting from excessive alcohol use, age, or lack of exercise, supplements may be able to help us bridge the gap, so to speak, towards a healthier lifestyle. Magnesium citrate is the most common type of magnesium supplement. It is a molecule that connects magnesium with citric acid, a flavor enhancer used regularly in the food industry. The citric acid increases the bioavailability of the magnesium, making it more easily absorbed into the digestive tract.

    Magnesium citrate can be used to increase magnesium levels in the body, as a laxative to support regular bowel movements, or to prepare for medical procedures, like a colonoscopy. It is important to always follow your physician’s instructions when preparing for a colonoscopy.

    How does magnesium citrate differ from other forms of magnesium?

    Magnesium citrate combines magnesium with citric acid to form a highly absorbable form of magnesium. With most magnesium supplements, the body is only able to absorb and assimilate a small percentage of the magnesium, but in the form of a mineral citrate, the body is able to absorb a significantly greater amount.

    Magnesium citrate's role in the body

    Though most commonly known as a saline laxative, magnesium citrate can also provide the body with much-needed magnesium. It has a higher bioavailability than the other types of magnesium and this high level of absorption is what makes it so beneficial.

    Health benefits of magnesium citrate

    Magnesium citrate helps to regulate the transport of calcium across cell membranes, playing a key role in bone creation and the maintenance of bone density. Nearly 60% of the body’s magnesium is stored in its bones. Magnesium also helps to promote normal cardiac rhythmicity, which is the steady depolarization and repolarization found in healthy hearts, by regulating the electrical signals that control the heart’s timing. It helps with the proper absorption of vitamin D and is responsible for muscle contraction, and sending electrical signals throughout the body.

    Magnesium citrate supplementation

    Magnesium citrate is an over-the-counter magnesium supplement that is made up of a one-to-one ratio of magnesium atoms per molecule of citrate . It is often referred to as a saline laxative because of its effectiveness in relieving occasional constipation (due to travel or change in diet) and colonoscopy prep.

    Occasional constipation relief and colonoscopy prep are not the only use for magnesium citrate supplements. Their main purpose is to provide nutritional support in the event of a magnesium deficiency, which is fairly common and largely unknown. Magnesium citrate is highly bioavailable and thus an excellent choice for magnesium supplementation.

    How long does magnesium citrate stay in your system?

    The process of absorption and utilization is fairly quick for most magnesium supplements, but especially for the highly bioavailable magnesium citrate. The body is constantly using magnesium and it usually remains in your system for anywhere from twelve to twenty-four hours.

    Recommended dosage

    The recommended dosage for magnesium citrate can vary depending upon a number of factors including the brand, the reason for supplementing, age, gender, and recommendation of a healthcare practitioner. If you are pregnant, lactating, or have a serious medical condition, check with your physician before taking supplements. The general guidelines for healthy individuals looking to supplement with magnesium citrate are:

    • Male 19 - 30 yo: 400mg per day, male over 30 yo: 420mg per day
    • Female 19 - 30 yo: 310mg per day, female over 30 yo: 320mg per day
    • Pregnant female under 30 yo: 350mg per day, pregnant female over 30 yo: 360mg per day
    • Lactating female any age: 320mg per day

    When is it best to take magnesium citrate?

    Depending on why you are supplementing with magnesium citrate, when you take it will vary. Your physician or healthcare provider may recommend magnesium citrate for a number of reasons, ranging from general supplementation for deficiency to colonoscopy prep. Each has its own specific requirements in terms of how to take, when to take, and how much to take. Follow your physician's recommendations exactly, especially if you are doing a colonoscopy prep.

    How long until magnesium citrate begins to work?

    If you are taking magnesium citrate for occasional constipation or colonoscopy prep, it should have the desired effect within 6 to 8 hours, though it may work in as little as 30 minutes. If you are taking a low dose daily, it should begin to work within 8 hours. The length of time it takes before it begins to work usually depends on how much you are taking and how sensitive your body is to magnesium citrate. If you are experiencing constipation or bowel changes always talk to your doctor as it may be a sign of a serious underlying condition.

    Is it safe to take magnesium citrate daily?

    As long as you are taking a low to moderate dose that is not causing loose stools, it is generally safe to take magnesium citrate daily. If you are using it as a laxative, strive for normal digestion and healthy bowel function by drinking water, eating plenty of dark leafy greens, pumpkin seeds, nuts, legumes, and bananas. A healthy lifestyle that includes regular exercise, minimal stress, and healthy sleep patterns could help to reduce reliance on a laxative. If you are experiencing chronic constipation or bowel changes always talk to your doctor as it may be a sign of a serious underlying condition.

    What happens if you miss a day?

    If you miss a day, take your supplement as usual the next day. It is important to take magnesium citrate supplement at or about the same time every day. If you forget to take it until much later in the day, it may be better to wait until the next day than to take two doses too closely together. Always follow the instructions provided by your doctor or the instructions printed on the label.

    Potential side effects and risks

    The potential side effects of taking magnesium citrate include diarrhea and digestive distress such as bloating, gas, gurgling stomach, cramps, and nausea. Always consult your doctor when beginning new supplementation.

    Magnesium citrate alternatives

    There are a number of magnesium citrate alternatives, including magnesium hydroxide from Irish seawater, magnesium glycinate, magnesium lactate, magnesium malate, magnesium sulfate, magnesium taurate, and magnesium chloride, many of which have fairly well-known brand names. Ask your doctor or pharmacist for recommendations if need be.

    Final takeaways

    Magnesium citrate is an over-the-counter magnesium supplement made from magnesium and citric acid. It is most well-known as a saline laxative because it is used widely for occasional constipation relief and to clear out the intestines for colonoscopies. If you are experiencing chronic constipation or bowel changes be sure to talk to your doctor as it may be a sign of a serious underlying condition.

    Taken regularly, magnesium citrate can also help alleviate a magnesium deficiency. Dosage is determined by the reasons for supplementation. There may be side effects, but they can be remedied by minor adjustment to the dosage. Magnesium citrate stays in your system from twelve to twenty-four hours and, if taken for its laxative effect, you may experience results in anywhere from 30 minutes to 6 hours. As always, consult your physician when taking any supplements.

    Care/of has an article What is Citrate of Magnesia that serves as a good resource for anyone considering a magnesium citrate supplement.

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    Dr. Carla Montrond Correia ND, CNS
    Medical Content Manager
    Dr. Montrond-Correia is a licensed naturopathic physician and a certified nutrition specialist (CNS). She holds degrees from University of Bridgeport, Georgetown University, and University of Saint Joseph, and supplemented her education with internships in the health and wellness space. She's focused on research, herbal medicine, nutrigenomics, and integrative and functional medicine. She makes time for exercise, artistic activities, and enjoying delicious food.
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