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    Magnesium Citrate

    Also known as: Mg citrate

    Magnesium ion bound to citric acid; citrate enhances solubility and intestinal absorption while providing mild osmotic laxative effect at higher doses.

    Last reviewed: 2026-06-23 · 1 indexed study

    Evidence Score
    70/100
    Magnesium repletionConstipation reliefSleep supportMuscle cramp prevention
    Data Completeness3/4 · 75%
    Evidence ScoreDosageSafetyLinked Studies

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    Overview

    Magnesium citrate is a highly bioavailable, mildly osmotic form of magnesium used for general repletion, mild constipation relief, and cramp/sleep support.

    Mechanism & Function

    Mechanism of Action

    Replenishes intracellular magnesium for >300 enzymatic reactions including ATP-binding, neuromuscular function, and vascular tone; citrate moiety enters TCA cycle.

    Physiological Role

    Useful for athletes experiencing cramps, poor sleep, or sub-optimal intake; supports recovery via improved sleep quality and neuromuscular relaxation.

    Primary Pathways

    Intestinal magnesium absorptionMg²⁺-ATP enzymatic functionNMDA receptor modulationVascular smooth muscle relaxation

    Performance / Health Relevance

    Higher bioavailability than oxide; provides usable magnesium for repletion in active populations who lose Mg through sweat.

    Evidence Review

    Overall70/100
    Human Clinical78/100
    Meta-AnalysisN/A

    No meta-analyses or systematic reviews indexed for this ingredient yet.

    Mechanistic85/100
    Real-World72/100
    Safety90/100

    Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.

    Compare Magnesium Forms

    5 magnesium forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.

    FormEvidence
    Magnesium CitrateThis page

    ~25–30% absorption — superior to oxide; below glycinate for neurological endpoints.

    70/100
    Magnesium Glycinate

    Glycinate chelation provides ~80% relative bioavailability vs ~4% for magnesium oxide.

    84/100
    Aquamin Mg

    Comparable to other Mg hydroxide forms.

    58/100
    Magnesium L-Threonate

    Described by the developers and trial abstracts as having superior ability to raise brain magnesium concentrations compared with other magnesium salts.

    54/100
    Magnesium Oxide

    In patients with marked intestinal malabsorption (ileal resection), magnesium oxide showed lower absorption compared with a magnesium diglycinate chelate in a crossover study (7815675).

    52/100
    Open full side-by-side comparison

    Practical Use & Dosage

    Minimum Effective Dose
    150 mg elemental Mg/day
    Optimal Range
    300–400 mg elemental Mg/day
    Upper / Caution Level
    ~400 mg/day supplemental before laxative effect
    Timing
    Evening (sleep support) or split doses
    Best Format
    Powder, capsule, liquid
    Bioavailability
    ~25–30% absorption — superior to oxide; below glycinate for neurological endpoints.
    Absorption Considerations
    Active and passive intestinal transport; high doses overflow to osmotic laxation.

    Safety & Interactions

    Side Effects

    • •Loose stools at >400 mg
    • •Mild GI cramping

    Contraindications

    • Severe renal impairment

    Drug Interactions

    • •Tetracyclines
    • •Fluoroquinolones
    • •Bisphosphonates

    Who Should Avoid

    • •End-stage kidney disease

    Monitoring

    Serum Mg in renal patients.

    Frequently Asked Questions

    Auto-generated from indexed evidence — dosage, safety, interactions, and more.

    When is Magnesium Citrate typically used or indicated?

    Magnesium Citrate is most commonly used for: Magnesium repletion, Constipation relief, Sleep support, Muscle cramp prevention. Useful for athletes experiencing cramps, poor sleep, or sub-optimal intake; supports recovery via improved sleep quality and neuromuscular relaxation.

    How does Magnesium Citrate work?

    Replenishes intracellular magnesium for >300 enzymatic reactions including ATP-binding, neuromuscular function, and vascular tone; citrate moiety enters TCA cycle.

    What is the recommended dose of Magnesium Citrate?

    The optimal range is 300–400 mg elemental Mg/day. with a minimum effective dose of 150 mg elemental Mg/day. Best taken: Evening (sleep support) or split doses. Upper / caution level: ~400 mg/day supplemental before laxative effect.

    What are the side effects of Magnesium Citrate?

    Reported side effects include: Loose stools at >400 mg; and Mild GI cramping. Monitoring: Serum Mg in renal patients.

    Does Magnesium Citrate interact with medications?

    Known or theoretical interactions: Tetracyclines; Fluoroquinolones; and Bisphosphonates. Always check with a clinician before combining with prescription medication.

    Who should avoid Magnesium Citrate?

    Magnesium Citrate is generally not recommended for: End-stage kidney disease; and Severe renal impairment.

    How strong is the evidence for Magnesium Citrate?

    Evidence level: Moderate (overall score 70/100), based on 1 indexed study on SuppIndex.

    Research & References (1)

    Magnesium bioavailability from magnesium citrate and magnesium oxide

    RCT2003Moderate
    PubMed

    Citrate produced significantly higher serum and urinary Mg vs oxide.

    Related Ingredients

    Other top-rated ingredients in Minerals.

    Magnesium Glycinate

    84/100

    An amino acid chelate of magnesium providing elemental Mg²⁺ bound to two glycine molecules, offering superior bioavailability and minimal gastrointestinal side effects.

    Calcium Citrate

    75/100

    Calcium bound to citric acid; ~24% elemental Ca by mass; absorbed across the small intestine via active transport and paracellular diffusion regardless of gastric pH.

    Zinc

    74/100

    Systematic reviews and meta-analyses of human trials show that oral zinc supplementation reduces duration and increases recovery rates in acute and persistent watery diarrhoea in children; lowers inflammatory lesion counts in acne; reduces pain severity in primary dysmenorrhea; and in small trials (20–30 mg/day) improved fasting glucose and 2‑hr OGTT in people with prediabetes. Adverse effects reported include increased vomiting in children receiving zinc for diarrhoea.

    Research Overview

    Moderate Evidence
    1Total Studies
    1Human Trials
    0Meta-Analyses
    2003Latest Study
    0Animal / In Vitro
    0Athlete Studies
    Primary data sourceGeneral Population
    Pooled evidence (meta-analysis / systematic review)No

    Cite this ingredient

    One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.

    Stable URL

    https://thesuppindex.com/ingredients/magnesium-citrate

    SuppIndex. (2026). Magnesium Citrate: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/magnesium-citrate

    Based on 1 indexed studies · Evidence level: Moderate.

    Goal Ratings

    General Health
    Sleep
    Recovery
    Hydration

    Stack Compatibility

    Compatible with B6, taurine, glycine; separate from minerals/antibiotics by 2 h.

    Vitamin B6TaurineGlycine