Magnesium citrate
Supplement
mineral salt
gutsleep
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Topping up magnesium · citrate absorbs better than oxide
When to take
Timing not addressed · 2 h+ from bisphosphonates
Take with
Water · higher doses draw water into the bowel
Pros & cons
Pros
- Among the better-absorbed forms per NIH ODS
- RDA is 310–420 mg a day for adults; food counts
- HSA allows muscle, nerve and electrolyte claims
Cons
- Magnesium salts are osmotic — diarrhea and cramping
- UL 350 mg a day from supplements — food doesn't count
- Sleep data cover magnesium broadly, not citrate
Sources
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Table 1 RDAs · read 2026-08-27
what it says
“Table 1: Recommended Dietary Allowances (RDAs) for Magnesium in Milligrams (mg) … 19–30 years | 400 mg | 310 mg … 31–50 years | 420 mg | 320 mg … 51+ years | 420 mg | 320 mg”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Health Risks from Excessive Magnesium (UL) · read 2026-08-27
what it says
“The Tolerable Upper Intake Level for supplemental magnesium is 350 mg for adults … The ULs only include magnesium from dietary supplements and medications; they do not include magnesium found naturally in food and beverages”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Dietary Supplements (absorption by form) · read 2026-08-27
what it says
“Small studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed more completely and is more bioavailable than magnesium oxide and magnesium sulfate”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Health Risks from Excessive Magnesium (GI effects) · read 2026-08-27
what it says
“The forms of magnesium that are most commonly reported to cause diarrhea include magnesium carbonate, chloride, gluconate, and oxide … The diarrhea and laxative effects of magnesium salts are due to the osmotic activity of unabsorbed salts”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Health Risks from Excessive Magnesium (renal function) · read 2026-08-27
what it says
“The risk of magnesium toxicity increases with impaired renal function or kidney failure because the ability to remove excess magnesium is reduced or lost”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Interactions with Medications (bisphosphonates, antibiotics) · read 2026-08-27
what it says
“Taking magnesium-rich supplements or medications at least 2 hours before or after oral bisphosphonates can minimize this interaction … These antibiotics should be taken at least 2 hours before or 4 to 6 hours after a magnesium-containing supplement”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Interactions with Medications (proton pump inhibitors) · read 2026-08-27
what it says
“Prescription proton pump inhibitor (PPI) drugs … can cause hypomagnesemia when taken for prolonged periods (typically more than a year)”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Interactions with Medications (diuretics) · read 2026-08-27
what it says
“Chronic treatment with loop diuretics … and thiazide diuretics … can increase the loss of magnesium in urine and lead to magnesium depletion … potassium-sparing diuretics … reduce magnesium excretion”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Dietary Supplements (elemental magnesium on labels) · read 2026-08-27
what it says
“The Supplement Facts panel on a dietary supplement label declares the amount of elemental magnesium in the product, not the weight of the entire magnesium-containing compound”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Sources of Magnesium: Food (Daily Value note) · read 2026-08-27
what it says
“The DV for magnesium is 420 mg for adults and children age 4 years and older”
- NIH ODS — Magnesium (Health Professional), updated January 6, 2026; read via web.archive.org capture 25 Aug 2026 — Magnesium supplements and medications (laxatives, antacids) · read 2026-08-27
what it says
“Magnesium is found in some remedies for heartburn and acid indigestion, and it is a key ingredient in certain laxatives … Magnesium is a primary ingredient in some laxatives”
- Examining the Effects of Supplemental Magnesium on Self-Reported Anxiety and Sleep Quality: A Systematic Review (Rawji et al., Cureus 2024) · read 2026-08-27
what it says
“Five out of eight sleep-related studies reported improvements in sleep parameters, while two studies reported no improvements, and one reported mixed results … Firm conclusions were limited by the heterogeneity of the data”
- ThyroMag: Single Center, Open-Label, Randomized Crossover Trial on Drug-Drug Interactions of Levothyroxine/Magnesium-Citrate and Levothyroxine/Magnesium-Aspartate in Healthy Subjects (Attinger et al., Clin Transl Sci 2025) · read 2026-08-27
what it says
“coadministration of magnesium citrate reduced thyroxine AUC non-significantly by 7% compared with levothyroxine alone … Hypothyroid patients should nonetheless take levothyroxine separated from magnesium-containing formulations”
- HSA — Health Supplements Guidelines GL-CHPB-3-001 (January 2026), clause 4.8 and Table 5 Minerals Limits · read 2026-08-27
what it says
“HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5 … Table 5: Minerals Limits … Magnesium 350 mg”
- HSA — Health Supplements Guidelines GL-CHPB-3-001 (January 2026), List of Health Claims, rows 55, 73, 80 · read 2026-08-27
what it says
“Contribute to normal muscle function • Calcium, potassium, magnesium … Maintain/support nervous system function • Copper, iodine, magnesium, potassium … Maintain/support body electrolyte balance • Magnesium”
- HSA — Guidelines on Prohibited and Restricted Ingredients in HS and TM (October 2025), clause 1.3 and Annex B row 65 (Magnesium) · read 2026-08-27
what it says
“The objective of this guideline is to highlight the substances of concern … 65. Magnesium — Restricted use in HS and TM … the maximum recommended daily dose should not provide more than 350mg”
- iHerb Singapore — 'Magnesium' category page, default order, 817 results · read 2026-08-27
what it says
“California Gold Nutrition, Magnesium Bisglycinate Chelate, Albion TRAACS® … NOW Foods, Magnesium Glycinate … Doctor's Best, High Absorption Magnesium Lysinate Glycinate … Life Extension, Neuro-Mag®, Magnesium L-Threonate … Thorne, Magnesium Glycinate”
Updated 2026-08-30. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.