Magnesium citrate



Magnesium citrate is a laxative used in bowel preparation for colonoscopy or as a magnesium supplement.

Brand Names
Generic Name
Magnesium citrate
DrugBank Accession Number

Magnesium citrate is a low volume and osmotic cathartic agent. The cathartic action works primarily through the high osmolarity of the solution which draws large amounts of fluid into space where is used.5 Magnesium citrate is considered by the FDA as an approved inactive ingredient for approved drug products under the specifications of oral administration of a maximum concentration of 237 mg.7 It is also considered as an active ingredient in over-the-counter products.6

Small Molecule
Average: 451.113
Monoisotopic: 449.9621801
Chemical Formula
  • Magnesium citrate
  • Magnesium dicitrate
  • Trimagnesium citrate
  • Trimagnesium dicitrate



Magnesium citrate has been used in bowel preparations prior to a colonoscopy as a cathartic agent.5

It is also used in over-the-counter products to relieve occasional constipation.8

Magnesium citrate can be one of the forms used for the administration of dietary supplements.9

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Associated Conditions
Contraindications & Blackbox Warnings
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The onset of action can be as early as 30 minutes after administration with a mean onset time of approximately 2 hours and a maximum action of 4 hours. The effect of magnesium citrate is highly dependent on the individual's hydration status.5

Mechanism of action

It mainly works through its property of high osmolality which will draw large amounts of fluid into the colonic lumen. There is also a possible stimulation of fluid excretion by cholecystokinin release and activation of muscle peristalsis.5


Mean plasma concentration of magnesium after administration of oral doses of magnesium citrate are reported to be of around 0.7 mmol/L and the concentration in saliva rested in 0.28 mmol/L. In reports, it has also been proven that the absorption and bioavailability of magnesium are greater when administered in the form of magnesium citrate when compared with other forms such as magnesium ocude.1

Volume of distribution

Not Available

Protein binding

Magnesium, once ionized, is highly bound to plasma proteins and it can represent even 90% of the magnesium found in blood plasma.3

Not Available
Route of elimination

After oral administration of magnesium citrate, there is a 40% increase in urine excretion of magnesium.2 Magnesium citrate is also widely eliminated via the feces because, when present in the bowel, it relaxes the bowel and pulls water into the intestine which increases bowel movement and a significant portion of this agent gets excreted by this via.10


The study of the half-life of magnesium citrate is very difficult due to the half-life of the available isotopes for magnesium.4


Not Available

Adverse Effects
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The occurrence of overdose with magnesium citrate is very unlikely but some of the signs of the presence of overdose are diarrhea or severe stomach pain.8

Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
AcetazolamideThe risk or severity of dehydration can be increased when Acetazolamide is combined with Magnesium citrate.
AclidiniumThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Aclidinium.
Alendronic acidMagnesium citrate can cause a decrease in the absorption of Alendronic acid resulting in a reduced serum concentration and potentially a decrease in efficacy.
AlfacalcidolThe serum concentration of Magnesium citrate can be increased when it is combined with Alfacalcidol.
AlfentanilThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Alfentanil.
AlloinThe risk or severity of adverse effects can be increased when Magnesium citrate is combined with Alloin.
AlmasilateThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Almasilate.
Aluminium phosphateThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Aluminium phosphate.
Aluminum hydroxideThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Aluminum hydroxide.
AmantadineThe therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Amantadine.
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Food Interactions
  • Take with or without food. Taking magnesium supplements with food may reduce the risk of diarrhea.


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Active Moieties
Magnesium cationionicT6V3LHY83822537-22-0JLVVSXFLKOJNIY-UHFFFAOYSA-N
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
BET-R-PREP Magnesium Citrate OralSolution1.745 g/1mLTopicalSatius Pharmaceuticals, Llc2017-11-18Not applicableUS flag
Citrate of MagnesiumLiquid1.745 g/29.6mLOralPhysicians Total Care, Inc.2003-01-29Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralC.D.M.A., INC2020-02-18Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralWakefern Foods Corporation1989-07-15Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralWalgreen Co2018-02-18Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralHarris Teeter2019-09-04Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralToppco2018-02-18Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralVi-Jon, LLC1989-07-15Not applicableUS flag
CitromaLiquid1.745 g/29.61mLOralMeijer Distribution Inc2014-05-19Not applicableUS flag
CitromaLiquid1.745 g/29.6mLOralWalgreens Co2000-07-14Not applicableUS flag
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
Cal-mag TabletMagnesium citrate (7 mg / tab) + Calcium lactate (48 mg / tab)TabletOralStandard Process Inc.Not applicableNot applicableCanada flag
Calcium and Magnesium Citrate and Vitamin D 250mg/125mg/200iuMagnesium citrate (125 mg) + Calcium citrate (250 mg) + Cholecalciferol (200 unit)TabletOralWn Pharmaceuticals Ltd.2001-11-232002-05-15Canada flag
Calcium and Magnesium Citrate With Vitamin DMagnesium citrate (137.5 mg) + Calcium citrate (275 mg) + Ergocalciferol (100 unit)TabletOralSisu Inc.1997-10-282005-07-13Canada flag
Calcium Lactate PowderMagnesium citrate (18 mg / g) + Calcium lactate (119 mg / g)PowderOralStandard Process Inc.Not applicableNot applicableCanada flag
Calcium Magnesium Plus Vitamin D LiquidMagnesium citrate (3 mg / mL) + Calcium gluconate (6 mg / mL) + Ergocalciferol (2 unit / mL) + Inositol (.6 mg / mL)LiquidOralJamp Pharma Corporation2002-04-222003-02-05Canada flag
ChildLife™ Essentials Liquid Calcium/Magnesium PlusMagnesium citrate (38 mg) + Calcium citrate (84 mg) + Cholecalciferol (33 IU) + Zinc citrate (0.7 mg)LiquidOralLAC GLOBAL BRANDS (MALAYSIA) SDN. BHD.2020-09-08Not applicableMalaysia flag
Daily Supplement PacksMagnesium citrate (150 mg) + Cyanocobalamin (125 mcg) + Folic acid (0.4 mg) + Pyridoxine (50 mg) + Ubidecarenone (30 mg) + Vitamin E (400 unit)CapsuleOralWn Pharmaceuticals Ltd.2002-10-182005-08-15Canada flag
Derma-forceMagnesium citrate (17 mg / cap) + Ascorbic acid (117 mg / cap) + Beta carotene (3333.3 unit / cap) + Biotin (300 mcg / cap) + Calcium citrate (42 mg / cap) + Cholecalciferol (100 unit / cap) + Choline bitartrate (25 mg / cap) + Cyanocobalamin (33.3 mcg / cap) + Folic acid (0.333 mg / cap) + Inositol (25 mg / cap) + Methionine (25 mg / cap) + Nicotinamide (7 mg / cap) + Octasulfur (8.33 mg / cap) + Pantothenic acid (33.3 mg / cap) + Pyridoxine hydrochloride (10 mg / cap) + Riboflavin (10 mg / cap) + Thiamine (10 mg / cap) + Zinc citrate (8.33 mg / cap) + alpha-Tocopherol succinate (33.3 unit / cap)CapsuleOralPrairie Naturals1997-04-012006-09-20Canada flag
Female AdvantageMagnesium citrate (16.67 mg / cap) + Zinc sulfate (3.33 mg / cap)CapsuleOralBody Wise International LlcNot applicableNot applicableCanada flag
FemidauseMagnesium citrate (20 mg / cap) + Calcium citrate (50 mg / cap) + Vitamin D (200 unit / cap)CapsuleOralPns Pharma Therapy1999-02-022009-08-05Canada flag
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
FolcyteineMagnesium citrate (16 mg/1) + Acetylcysteine (200 mg/1) + Calcium citrate tetrahydrate (47 mg/1) + Cholecalciferol (800 [iU]/1) + Folic acid (1000 ug/1)TabletOralPureTek Corporation2023-09-14Not applicableUS flag
PCP 100 KitMagnesium citrate (1.745 g/29.6mL) + Bisacodyl (5 mg/1) + Metoclopramide hydrochloride (10 mg/1) + Petrolatum (0.76 g/1g) + Polyethylene glycol (17 g/17g)KitOralAsclemed Usa, Inc.2014-01-02Not applicableUS flag
Prenatal Chelated MineralMagnesium citrate (75 mg/1) + Calcium carbonate (30 mg/1) + Calcium citrate tetrahydrate (32.5 mg/1) + Copper gluconate (0.5 mg/1) + Ferrous fumarate (7 mg/1) + Potassium Iodide (75 ug/1) + Zinc citrate (5 mg/1)TabletOralUsana Health Sciences, Inc.2012-04-112017-12-31US flag


ATC Codes
B05CB03 — Magnesium citrateA12CC04 — Magnesium citrateA06AD19 — Magnesium citrate
Drug Categories
Chemical TaxonomyProvided by Classyfire
This compound belongs to the class of organic compounds known as tricarboxylic acids and derivatives. These are carboxylic acids containing exactly three carboxyl groups.
Organic compounds
Super Class
Organic acids and derivatives
Carboxylic acids and derivatives
Sub Class
Tricarboxylic acids and derivatives
Direct Parent
Tricarboxylic acids and derivatives
Alternative Parents
Tertiary alcohols / Carboxylic acid salts / Carboxylic acids / Organic salts / Organic oxides / Hydrocarbon derivatives / Carbonyl compounds
Alcohol / Aliphatic acyclic compound / Carbonyl group / Carboxylic acid / Carboxylic acid salt / Hydrocarbon derivative / Organic oxide / Organic oxygen compound / Organic salt / Organooxygen compound
Molecular Framework
Not Available
External Descriptors
Not Available
Affected organisms
  • Humans and other mammals

Chemical Identifiers

CAS number
InChI Key
trimagnesium(2+) bis(2-hydroxypropane-1,2,3-tricarboxylate)


General References
  1. Walker AF, Marakis G, Christie S, Byng M: Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003 Sep;16(3):183-91. [Article]
  2. Rylander R, Megevand Y, Lasserre B, Amstutz W, Granbom S: Moderate alcohol consumption and urinary excretion of magnesium and calcium. Scand J Clin Lab Invest. 2001;61(5):401-5. [Article]
  3. Nielsen SP: Free and protein-bound magnesium in normal human plasma determined by ultracentrifugation and ultrafiltration. Scand J Clin Lab Invest. 1969 May;23(3):219-25. [Article]
  4. Jahnen-Dechent W, Ketteler M: Magnesium basics. Clin Kidney J. 2012 Feb;5(Suppl 1):i3-i14. doi: 10.1093/ndtplus/sfr163. [Article]
  5. Kim D. and Pickhardt P. (2010). CT Colonography. Elsevier.
  6. Health Canada [Link]
  7. FDA Inactive ingredient search [Link]
  8. Dailymed [Link]
  9. Supplements manufacturer [Link]
  10. Magnesium citrate [File]
PubChem Compound
PubChem Substance
Download (231 KB)

Clinical Trials

Clinical Trials
4Active Not RecruitingTreatmentChronic Heart Failure (CHF) / Congestive Heart Failure (CHF) / Diuretics Drug Reactions1
4Active Not RecruitingTreatmentPatients Undergoing Elective Colonoscopy1
4CompletedNot AvailableBowel preparation therapy / Colonoscopy1
4CompletedTreatmentBowel Preparation for Colonoscopy1
4CompletedTreatmentColon Cleansing1
4Unknown StatusDiagnosticUlcerative Colitis1
4Unknown StatusTreatmentColonic Diseases1


Not Available
Not Available
Dosage Forms
SolutionTopical1.745 g/1mL
LiquidOral1.745 g/29.61mL
SolutionOral1.745 g/29.61mL
Powder, for solutionOral16 g/16g
CapsuleOral250 mg
LiquidOral1.745 g/29.6mL
LiquidOral2.62 g/100mL
LiquidOral2.65 mg/100mL
SolutionOral0.059 g/1mL
CapsuleOral100 mg
CapsuleOral90 mg / cap
CapsuleOral150 mg
TabletOral300 mg
SolutionOral1.745 g/29.6mL
LiquidOral2.65 g/100mL
LiquidOral1.75 g / 100 mL
Powder, for solutionOral17 g/17g
LozengeOral610 mg
LozengeOral610.09 mg
Granule, for solutionOral
Powder, for solutionOral
TabletOral200 mg
Tablet, film coatedOral
Powder, for solutionOral17 g/100g
Powder, for solutionOral
KitOral; Rectal
Not Available
Not Available


Experimental Properties
melting point (°C)184 ºC'MSDS'
water solubilityPartially soluble in cold water'MSDS'
Predicted Properties
Water Solubility6.34 mg/mLALOGPS
pKa (Strongest Acidic)3.05Chemaxon
pKa (Strongest Basic)-4.2Chemaxon
Physiological Charge-3Chemaxon
Hydrogen Acceptor Count7Chemaxon
Hydrogen Donor Count1Chemaxon
Polar Surface Area140.62 Å2Chemaxon
Rotatable Bond Count10Chemaxon
Refractivity68.14 m3·mol-1Chemaxon
Polarizability14.25 Å3Chemaxon
Number of Rings0Chemaxon
Rule of FiveYesChemaxon
Ghose FilterNoChemaxon
Veber's RuleNoChemaxon
MDDR-like RuleNoChemaxon
Predicted ADMET Features
Not Available


Mass Spec (NIST)
Not Available
Not Available

Drug created at December 03, 2015 16:51 / Updated at November 30, 2023 01:44