Magnesium Glycinate vs Magnesium Citrate

Magnesium glycinate (magnesium bisglycinate) vs Magnesium citrate

Evidence Level: promising

If you want daily magnesium without looser stools, choose glycinate. If you need constipation relief or don't mind a mild laxative effect, choose citrate. Evidence for sleep/stress benefits is modest regardless of form ^[3]^[4]^[7]^[9].

Both raise magnesium; citrate has stronger human data for absorption vs oxide and for laxative use, while glycinate is favored for GI tolerability and nightly routines. Start with 100–200 mg elemental Mg/day, pick glycinate if stool-sensitive, and pick citrate if regularity is desired. Keep supplemental Mg ≤350 mg/day unless supervised, separate from interacting meds, and avoid high doses with kidney disease ^[3]^[7]^[9]^[10]^[11].

The Comparison

AMagnesium glycinate (magnesium bisglycinate)

Standardization: Chelated form; typical pure chelate ~14% elemental Mg by mass; beware "buffered" blends with added oxide that raise % Mg but lower chelate purity [^1][^2].

Dosage: 100–200 mg elemental Mg/day for general use; stay ≤350 mg/day supplemental per NIH unless supervised [^3].

Benefits

•Generally gentler on GI tract vs osmotic salts at comparable elemental doses (clinical lore; limited direct trials) ^[3].
•Chelate form commonly used for nightly routines (sleep/stress) when diarrhea is a concern; evidence for magnesium helping sleep is modest overall ^[4].

Drawbacks

•Fewer direct head-to-head bioavailability data vs citrate; quality varies (buffered products) ^[1]^[2].

Safety:Same magnesium interactions/UL as other forms; separate from tetracyclines/quinolones and bisphosphonates; caution in CKD ^[3].

BMagnesium citrate

Standardization: Often supplied as trimagnesium dicitrate (anhydrous ~16% Mg) or nonahydrate (~11% Mg). Labels should declare elemental Mg [^5][^6].

Dosage: 100–200 mg elemental Mg/day for supplementation; higher single doses used short-term as saline laxative per OTC labeling/clinical practice [^7][^8].

Benefits

•Well-studied organic salt with good solubility and higher bioavailability than oxide in RCTs ^[9]^[10].
•Effective osmotic laxative; widely used in bowel prep (multiple RCTs and monograph support) ^[7]^[8]^[11]^[12].

Drawbacks

•More likely to loosen stools at typical doses (osmotic effect), which some users find limiting ^[7]^[8].

Safety:Avoid or use cautiously in CKD; risk of electrolyte shifts and rare hypermagnesemia with excess or laxative use ^[3]^[13].

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Head-to-Head Analysis

Efficacy for common goals (sleep, stress, general repletion) Critical

Winner:Tie• Importance: high

Meta-analysis shows small benefits of oral magnesium for insomnia in older adults; effects are form-agnostic and low-certainty. No robust head-to-head glycinate vs citrate for sleep/stress; both deliver elemental Mg ^[4].

Constipation/regularity Critical

Winner:Magnesium citrate• Importance: high

Citrate is an established saline laxative and component of bowel-prep regimens in RCTs and the OTC monograph; glycinate lacks laxative evidence ^[7]^[11]^[12].

GI tolerability at typical supplemental doses Critical

Winner:Magnesium glycinate (magnesium bisglycinate)• Importance: high

Chelated forms are generally chosen to minimize diarrhea; citrate's osmotic effect more often loosens stools at comparable elemental doses (indirect evidence, clinical practice) ^[3]^[7]^[8].

Bioavailability/absorption evidence

Winner:Magnesium citrate• Importance: medium

Citrate shows superior bioavailability vs oxide in crossover RCTs and is among organic salts with better absorption than poorly soluble forms; direct glycinate head-to-head data are limited ^[9]^[10]^[3].

Standardization/label clarity

Winner:Tie• Importance: medium

Both should list elemental Mg. Citrate percent Mg varies by hydrate; glycinate is ~14% when pure but is often "buffered" with oxide—check labels ^[5]^[6]^[1]^[2].

Cost/value per effective dose

Winner:Tie• Importance: low

Prices vary widely by brand and form; value depends more on elemental Mg per serving and tolerability than salt type (no consistent, high-quality cost advantage across markets).

Common Questions

How much should I take daily?

Commonly 100–200 mg elemental magnesium/day. Keep supplemental Mg ≤350 mg/day unless prescribed. Adjust based on GI tolerance and dietary intake ^[3].

Will glycinate help me sleep better than citrate?

Evidence for magnesium improving sleep is small and low-certainty, with no head-to-head data between these forms. Choose based on tolerability ^[4].

Which is better absorbed?

Citrate shows good human data and outperforms oxide; glycinate likely similar to other organic salts but has less direct head-to-head research ^[9]^[3].

Can I take magnesium with my medications?

Separate from tetracyclines/quinolones by 2–6 hours and from bisphosphonates by ≥2 hours; ask your clinician if unsure ^[3].

How do I read labels for elemental magnesium?

Look for "Magnesium (as ...) — X mg." That X is elemental Mg. Beware glycinate products "buffered" with oxide that inflate % Mg ^[5]^[2].

Which Should You Choose?

Nightly supplement for sleep/stress without laxative effect

Choose:Magnesium glycinate (magnesium bisglycinate)

Pick glycinate for gentler GI profile; overall sleep evidence for magnesium is modest, so prioritize tolerability and routine use ^[3]^[4].

Occasional constipation or preference for looser stools

Choose:Magnesium citrate

Citrate acts as an osmotic laxative and is widely used in bowel-prep protocols; start with label-directed doses and hydrate ^[7]^[11]^[12].

General magnesium repletion when absorption is a concern

Choose:Magnesium citrate

Citrate has human data showing better bioavailability than oxide and is a well-soluble organic salt ^[9]^[10]^[3].

Taking antibiotics (tetracyclines/quinolones) or bisphosphonates

Choose: Either option

Either form can chelate these drugs; separate dosing (2 h before or 4–6 h after for antibiotics; ≥2 h for bisphosphonates) or defer supplementing during therapy ^[3].

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