Comparison
Magnesium Glycinate vs Metformin
Side-by-side of Magnesium Glycinate and Metformin. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Magnesium Glycinate
Magnesium glycinate supplement guide: chelated bisglycinate form, 200 to 400 mg dosage, sleep architecture benefits, low GI side effects, glycine co-effect.
Metformin
Metformin for longevity: biguanide mechanism of action, TAME trial status, anti-aging dosage, weight loss data, life extension evidence in non-diabetics.
Effects at a glance
Magnesium Glycinate
- •Shortens sleep onset latency in older adults and in deficient populations supplementing 200 to 400 mg elemental Mg
- •Improves subjective sleep quality scores (PSQI, ISI) modestly versus placebo over 4 to 8 weeks
- •Reduces nocturnal leg cramps and exercise-induced muscle cramping in some controlled trials
- •Lowers self-reported anxiety in mild-to-moderate cases, with smaller effect than first-line pharmacotherapy
- •Glycinate form delivers fewer GI side effects than oxide or citrate at equivalent elemental doses
- •Insufficient as a stand-alone hypertension treatment; small adjunctive blood-pressure reductions only
Metformin
- •Reduces HbA1c by ~1.0 to 1.5 percentage points in type 2 diabetes; first-line agent in major guidelines
- •DPP trial: 31% reduction in T2DM incidence in adults with prediabetes over 2.8 years
- •Suppresses hepatic gluconeogenesis via AMPK activation and complex I inhibition
- •Long-term use depletes B12; annual monitoring recommended after year 2
- •Lifespan extension in non-diabetic humans is not established; TAME trial pending
- •MASTERS trial reported blunted resistance-training hypertrophy in older adults
Side-by-side
| Attribute | Magnesium Glycinate | Metformin |
|---|---|---|
| Category | supplement | pharmaceutical |
| Also known as | magnesium bisglycinate | Glucophage, Fortamet, Glumetza, dimethylbiguanide |
| Half-life (hr) ↗ | 5 | 6 |
| Typical dose (mg) ↗ | 300 | 1500 |
| Dosing frequency | daily (often evening) | 1 to 3 times daily with meals; XR once daily |
| Routes | oral | oral |
| Onset (hr) | 1 | 1 |
| Peak (hr) | - | 2.5 |
| Molecular weight | - | 129.16 |
| Molecular formula | - | C4H11N5 |
| Mechanism | Magnesium acts as a cofactor for 300+ enzymes and as a voltage-dependent antagonist at NMDA receptors; glycine serves as an inhibitory neurotransmitter and co-agonist at glycine receptors. | Suppresses hepatic gluconeogenesis primarily via AMPK activation and complex I inhibition; modestly improves peripheral insulin sensitivity and shifts gut microbiome composition. |
| Legal status | Dietary supplement | Prescription only (FDA approved for type 2 diabetes 1994) |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | Rx only (not a controlled substance) |
| Pregnancy | Generally considered acceptable at RDA doses; consult clinician | Category B; used in gestational diabetes and PCOS per current guidance |
| CAS | 14783-68-7 | 657-24-9 |
| PubChem CID | 84645 | 4091 |
| Wikidata | - | Q19484 |
Safety profile
Magnesium Glycinate
Common side effects
- mild GI upset at high doses
- loose stools (dose-dependent, less than with oxide/citrate forms)
Contraindications
- severe renal impairment
- myasthenia gravis
- heart block
Interactions
- tetracycline and fluoroquinolone antibiotics: magnesium chelates antibiotic, reducing absorption; separate by 2+ hours(moderate)
- bisphosphonates: reduced absorption of bisphosphonate(moderate)
- potassium-sparing diuretics: possible hypermagnesemia in renal impairment(moderate)
Metformin
Common side effects
- nausea
- diarrhea
- abdominal discomfort
- metallic taste
- decreased appetite
- B12 depletion (long-term)
Contraindications
- eGFR below 30 mL/min/1.73m2
- acute or chronic metabolic acidosis
- severe hepatic impairment
- acute heart failure
- iodinated contrast within 48 hours
Interactions
- iodinated contrast media: renal injury risk; hold 48 hours peri-imaging(major)
- alcohol (heavy use): elevated lactic acidosis risk(major)
- cimetidine: raises metformin plasma levels via OCT2 inhibition(moderate)
- insulin and sulfonylureas: additive hypoglycemia risk in combination(moderate)
- dolutegravir: raises metformin exposure via OCT2(moderate)
Which Should You Take?
Magnesium Glycinate comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Metformin is the right call when one of the conditionals below applies.
- → If your priority is sleep onset or sleep quality, pick Magnesium Glycinate.
- → If your priority is post-training recovery, pick Magnesium Glycinate.
- → If your priority is metabolic health and glucose control, pick Metformin.
- → If your priority is healthspan extension, pick Metformin.
Edge case: If you want to avoid prescription-only, Magnesium Glycinate is the more accessible choice.
Default choice: Magnesium Glycinate. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Metformin only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Magnesium Glycinate and Metformin?
Magnesium Glycinate and Metformin differ in category (supplement vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Magnesium Glycinate or Metformin?
Magnesium Glycinate half-life is 5 hours; Metformin half-life is 6 hours.
Can you stack Magnesium Glycinate with Metformin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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