Excellent bioavailability
Better absorbed than oxide with good tolerance
Magnesium Citrate
Well-absorbed form of magnesium bound to citric acid, excellent for digestive health and gentle constipation relief
Scientific nameMagnesium Citrate
FormulaC12H10Mg3O14
Molecular weight451.11 g/mol
CAS7779-25-1
35
absorption score
8
safety / 10
15
USD per month
16
elemental magnesium %
5
documented interactions
Check it against something
Magnesium Citrate with:
- Amylase
- Ashwagandha
- Avocado Oil
- BCAA (Branched-Chain Amino Acids)
- Beetroot Powder
- Beta-Alanine
- Bifidobacterium lactis
- Bifidobacterium longum
- Bovine Collagen
- Caffeine
- Calcium
- Calcium Bone Formula
- Calcium Carbonate
- Casein Protein
- Chicken Collagen
- Choline (Bitartrate)
- Chondroitin Sulfate
- Coconut Oil
- Collagen Peptides
- Comprehensive Immune Support Complex
- Comprehensive Multivitamin-Mineral Complex
- Creatine HCL
- Creatine Monohydrate
- D-Mannose
- DHA
- Electrolyte Blend
- EPA
- Fish Oil (EPA/DHA)
- Folate (5-MTHF)
- Ginger
- Iron Fumarate
- Iron Sulfate
- Joint Mobility Formula
- Keratin
- Krill Oil
- L-Carnitine
- L-Citrulline
- Lactase
- Lactobacillus acidophilus
- Lactobacillus rhamnosus
- Lipase
- Magnesium Glycinate
- Magnesium Oxide
- Marine Collagen
- Melatonin
- Modafinil
- Olive Oil Extract
- Omega-3 + Curcumin + Vitamin D Triple Anti-Inflammatory Formula
- Papain
- Protease
- Saccharomyces boulardii
- Turmeric
- Vitamin B12 (Cyanocobalamin)
- Vitamin B12 (Methylcobalamin)
- Vitamin C (Ascorbic Acid)
- Vitamin C (Sodium Ascorbate)
- Vitamin D3
- Whey Protein
- Zinc Gluconate
Nothing found
99
out of 100
Works better together
Compatible. Timing differs, so follow each supplement's own window.
What it does
mechanism and evidence for each claimGentle constipation relief
Mild laxative effect without harsh digestive upset
Good digestive tolerance
Less likely to cause diarrhea than oxide forms
Balanced cost-effectiveness
Good balance of price, absorption, and effectiveness
Sleep and muscle support
Effective for sleep quality and muscle relaxation
Others take these for the same thing
Same goal, different mechanism — check any of them against this one
Probiotics for Autoimmune Disease Support
Gut health & immune modulation
10-100 billion CFU daily
B
60%
Magnesium Glycinate
Superior absorption sleep & muscle support
200-600 mg
A
90%
Chloride
Electrolyte & digestive support
2300mg
A
95%
Bone Broth Collagen
Gut healing & collagen support
20-40g powder
B
85%
Psyllium Husk
Digestive health & cholesterol support
5-15g
A
95%
Lactase
Lactose digestion & dairy tolerance
3,000-9,000 ALU units
A
95%
Or a different form of the same thing
the comparison people search most
Magnesium Citrate vs Magnesium Glycinate
absorption 35 against 90 ·
$15 against $25 a month
90%
Magnesium Citrate vs Magnesium Oxide
absorption 35 against 4 ·
$15 against $8 a month
4%
Magnesium Citrate vs Magnesium Chloride
absorption 35 against 50 ·
$15 against $20 a month
50%
Magnesium Citrate vs Magnesium Malate
absorption 35 against 40 ·
$15 against $35 a month
40%
Magnesium Citrate vs Magnesium L-Threonate
absorption 35 against 95 ·
$15 against $120 a month
95%
Every pair we checked
12 combinations scored by the engine
Magnesium Citrate + Iron Sulfate
High iron doses may compete with magnesium
Needs attention
58
Magnesium Citrate + Calcium Carbonate
High calcium can interfere with magnesium absorption
Needs attention
64
Magnesium Citrate + Caffeine
No documented interaction either way
No known interaction
70
Magnesium Citrate + Creatine Monohydrate
No documented interaction either way
No known interaction
70
Magnesium Citrate + Whey Protein
No documented interaction either way
No known interaction
70
Magnesium Citrate + Lactase
No documented interaction either way
No known interaction
70
Magnesium Citrate + Bovine Collagen
No documented interaction either way
No known interaction
70
Magnesium Citrate + DHA
No documented interaction either way
No known interaction
70
Magnesium Citrate + Turmeric
No documented interaction either way
No known interaction
70
Magnesium Citrate + Vitamin C (Ascorbic Acid)
Magnesium required for vitamin D metabolism
Works better together
90
Magnesium Citrate + Potassium Citrate
Both support cardiovascular and muscle function
Works better together
90
Magnesium Citrate + Vitamin D3
Magnesium required for vitamin D metabolism
Works better together
99
Dosage
Daily300-600 mg
Maintenance300-500 mg daily
Therapeutic500-1000 mg daily
Constipation400-800 mg before bed
Elemental magnesiumContains ~16% elemental magnesium
Upper limit
350 mg from supplements NIH ODS
Before you take it
VeganYes
When to expect it
First Effects6-24 hours for digestive effects, 1-2 weeks for deficiency correction
Peak Benefits4-8 weeks for comprehensive magnesium benefits
Deficiency DevelopmentWeeks to months with inadequate intake
Toxicity OnsetRare with oral supplements, mainly loose stools
How to measure it
MarkerSerum magnesium or RBC magnesium
OptimalSerum: 1.7-2.2 mg/dL, RBC: 4.2-6.8 mg/dL
Deficient belowSerum: <1.7 mg/dL, RBC: <4.2 mg/dL
FrequencyEvery 6-12 months if supplementing regularly
RBC magnesium more accurate for cellular magnesium status
What people actually reported to the FDA
CAERS, 379 reports naming it as the suspectMost reported effects
Excluded from the list above: choking (55), foreign body (27), dysphagia (22). Those are people struggling with the tablet itself, not with the compound.
Named as the suspect
379 reports
of 1,000+ that mention it at all
Serious outcome
87%
hospitalisation, emergency room or worse
Other Serious or Important Medical Event283
Hospitalization81
Visited Emergency Room53
Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →
What actually reaches you
The label counts the carrier, your body does not
Elemental magnesium
16.2%
of 451.11 g/mol
Absorption
Moderate 35 of 100 · middle of the range for this compound
Measured
25% of the dose
PubMed 2407766
Reaches blood daily
18.2 mg
Cost per 100 mg absorbed
$2.74 vs $15/month on the label
A 500 mg capsule of Magnesium Citrate contains 81 mg of magnesium. At the measured 25% absorption that is about 20.3 mg reaching your blood. How this is calculated →
Works better with
+
Vitamin D
Magnesium required for vitamin D metabolism
Cofactor for vitamin D converting enzymes · level A
+
Vitamin B6
B6 enhances magnesium cellular uptake
Improves magnesium transport into cells · level B
+
Potassium
Both support cardiovascular and muscle function
Complementary electrolyte balance · level AWhat not to take with Magnesium Citrate
!
Calcium Excess
High calcium can interfere with magnesium absorption
Competition for absorption pathways · moderate significance
!
Iron High Dose
High iron doses may compete with magnesium
Mineral competition for absorption · mild significanceMedication interactions
Discuss these with a pharmacist before combiningMagnesium reduces antibiotic absorption
What to do: Space doses 2-4 hours apart
Reduces bisphosphonate absorption
What to do: Take bisphosphonate 2 hours before magnesium
Some diuretics increase magnesium loss
What to do: Monitor magnesium status, may need higher doses
Available forms
Ranks 5 of 6 among magnesium forms. Magnesium L-Threonate absorbs better — 95%. Compare all forms →
Magnesium Citrate (Powder/Capsules): Good absorption, Gentle laxative, Digestive friendly, Moderate cost
Food sources
Magnesium citrate not found naturally in foods
Only available as supplement · 35
Citrus fruits (provide citric acid)
Natural citric acid may enhance absorption · 50
Dark leafy greens (natural magnesium)
150-200mg per cup cooked · 50
Too little
- Muscle cramps and spasms
- Insomnia and poor sleep quality
- Anxiety and irritability
- Fatigue and weakness
- Heart palpitations
- Headaches and migraines
- Constipation
Too much
- Loose stools and mild diarrhea (most common)
- Mild digestive discomfort
- Muscle weakness (rare)
- Low blood pressure (rare)
- Generally excellent safety profile
Who benefits most
constipation-mild-chronic
Gentle and effective for regular bowel movement support
300-600 mg before bed
magnesium-deficiency-correction
Good absorption for correcting deficiency without harsh effects
400-800 mg daily (divided doses)
budget-bioavailability-balance
Want better absorption than oxide without premium prices
300-600 mg daily
digestive-sensitive
Better tolerated than oxide but more affordable than chelated
200-400 mg daily
sleep-muscle-support
Effective for sleep and muscle issues with good value
400-600 mg before bedWhere to buy it
Look for Magnesium Citrate at 300-600 mg per serving. The form that matters here is Magnesium Citrate (Powder/Capsules).
Find on Amazon
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How it works
- Citric acid enhances magnesium solubility in intestinal fluids
- Better absorbed than oxide due to improved dissolution
- Citrate component may have mild chelating effects
- Osmotic laxative effect but gentler than oxide
- Absorbed throughout small intestine with moderate efficiency
- Excess citrate may provide metabolic benefits
Key findings
what the evidence supports- Significantly better absorbed than magnesium oxide (clinical studies)
- Effective for mild constipation relief with good tolerance
- Good balance of cost, absorption, and effectiveness
- Less digestive upset than oxide forms in comparative studies
Sources: NIH Examine.com · data reviewed 2026-08-02
Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →
Common questions
What are the benefits of Magnesium Citrate?
Documented effects: Excellent bioavailability; Gentle constipation relief; Good digestive tolerance; Balanced cost-effectiveness. Better absorbed than oxide with good tolerance
How much Magnesium Citrate should you take per day?
The common daily range is 300-600 mg. By goal — maintenance: 300-500 mg daily; therapeutic: 500-1000 mg daily; constipation: 400-800 mg before bed; elemental magnesium: Contains ~16% elemental magnesium.
When is the best time to take Magnesium Citrate?
Evening with food. First effects are typically reported within 6-24 hours for digestive effects, 1-2 weeks for deficiency correction.
What are the side effects of Magnesium Citrate?
At excessive doses: Loose stools and mild diarrhea (most common), Mild digestive discomfort, Muscle weakness (rare), Low blood pressure (rare), Generally excellent safety profile. Safety rating at normal doses is 8 out of 10.
What should you not take with Magnesium Citrate?
Separate it from Calcium Excess, Iron High Dose by two to four hours. High calcium can interfere with magnesium absorption
Does Magnesium Citrate interact with medications?
Documented interactions with antibiotics-tetracycline-quinolones, bisphosphonates, diuretics-loop-thiazide. Discuss these with a pharmacist before combining.
How much Magnesium Citrate is too much?
The tolerable upper intake level is 350 mg from supplements per day for adults, per NIH ODS. Above that, the risk of adverse effects rises: Loose stools and mild diarrhea (most common), Mild digestive discomfort, Muscle weakness (rare).
How do you know if you need Magnesium Citrate?
The marker is Serum magnesium or RBC magnesium, optimal range Serum: 1.7-2.2 mg/dL, RBC: 4.2-6.8 mg/dL. Common deficiency signs: Muscle cramps and spasms, Insomnia and poor sleep quality, Anxiety and irritability, Fatigue and weakness.