Comparison
Magnesium Glycinate vs Melatonin
Side-by-side of Magnesium Glycinate and Melatonin. 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.
Melatonin
Melatonin as a sleep supplement: 0.3-1 mg matches physiological output, 3-10 mg is pharmacological. Shifts circadian phase, shortens sleep latency.
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
Melatonin
- •Shortens sleep onset latency by ~7 to 12 minutes at physiological 0.3 to 1 mg doses
- •Advances circadian phase when taken 30 to 60 minutes before target bedtime, useful for jet lag and shift work
- •Does not meaningfully increase total sleep time in healthy adults without circadian misalignment
- •Endogenous nighttime production is not suppressed by short-term exogenous supplementation
- •Higher doses (3 to 10 mg) raise plasma levels above physiological range and often increase morning grogginess
- •Effective for delayed sleep-wake phase disorder and reducing jet-lag severity in eastward travel
Side-by-side
| Attribute | Magnesium Glycinate | Melatonin |
|---|---|---|
| Category | supplement | supplement |
| Also known as | magnesium bisglycinate | N-acetyl-5-methoxytryptamine |
| Half-life (hr) ↗ | 5 | 0.75 |
| Typical dose (mg) ↗ | 300 | 0.5 |
| Dosing frequency | daily (often evening) | daily, 30 to 60 minutes before target sleep time |
| Routes | oral | oral, sublingual |
| Onset (hr) | 1 | 0.5 |
| Peak (hr) | - | 1 |
| Molecular weight | - | 232.28 |
| Molecular formula | - | C13H16N2O2 |
| 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. | Agonist at MT1 and MT2 receptors in the suprachiasmatic nucleus, signaling biological night and promoting sleep-onset gating plus circadian phase shifts. |
| Legal status | Dietary supplement | OTC in US; prescription in UK, EU, Japan |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | OTC supplement in US; Rx in UK, EU, Japan, Australia |
| Pregnancy | Generally considered acceptable at RDA doses; consult clinician | Insufficient data; not routinely recommended |
| CAS | 14783-68-7 | 73-31-4 |
| PubChem CID | 84645 | 896 |
| Wikidata | - | Q179243 |
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)
Melatonin
Common side effects
- vivid dreams
- morning grogginess (higher doses)
- headache
- dizziness
Contraindications
- autoimmune disease (theoretical)
- concurrent anticoagulant therapy without monitoring
Interactions
- fluvoxamine: CYP1A2 inhibition raises melatonin levels substantially(major)
- warfarin: possible increased bleeding risk(moderate)
- benzodiazepines and alcohol: additive sedation(moderate)
- antihypertensives: may alter blood pressure response(minor)
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. Melatonin is the right call when one of the conditionals below applies.
- → If your priority is post-training recovery, pick Magnesium Glycinate.
- → If your priority is stress and HPA-axis regulation, pick Magnesium Glycinate.
- → If your priority is circadian regulation, pick Melatonin.
Edge case: Half-lives differ materially (Magnesium Glycinate ~5 hr vs Melatonin ~0.75 hr). Magnesium Glycinate reaches steady state faster; Melatonin is easier to dial in if tolerability is uncertain.
Default choice: Magnesium Glycinate. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Melatonin 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 Melatonin?
Magnesium Glycinate and Melatonin differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Magnesium Glycinate or Melatonin?
Magnesium Glycinate half-life is 5 hours; Melatonin half-life is 0.75 hours.
Can you stack Magnesium Glycinate with Melatonin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper