Magnesium Glycinate vs Magnesium Oxide
Two forms of the same compound. What differs is how much of it your body absorbs, how well you tolerate it and what it costs per month.
Side by side
Green marks the better value| Magnesium Glycinate | Magnesium Oxide | |
|---|---|---|
| Absorption score | 90/100 | 4/100 |
| Elemental mineral | 14.1% | 60.3% |
| Cost per 100 mg delivered | $1.64 | $1.84 |
| Safety rating | 9/10 | 7/10 |
| Cost per month | $25 | $8 |
| Daily dose | 200-600 mg | 400-800 mg |
| Best timing | Evening with or without food | Divided doses with meals |
| Evidence level | A | A |
Verdict
Magnesium Glycinate wins on 3 of the measurable metrics.
It scores 90/100 against 4/100 on absorption, which is what decides how much of the dose actually reaches you. It does cost more per month — that is the trade-off.
What actually differs
Magnesium Glycinate
Highly bioavailable chelated form of magnesium bound to glycine amino acids for superior absorption
- Superior absorption
- Gentle on stomach
- Calming effects
- High quality
- More expensive
- May cause drowsiness
- Lower elemental magnesium %
- Potential hypotension
Magnesium Oxide
Most common and economical form of magnesium supplement with high elemental magnesium content but lower bioavailability
- Lowest cost
- Highest elemental Mg
- Laxative effect
- Long shelf life
- Poor absorption
- Digestive upset
- Requires divided doses
- Drug interactions
What each form is for
Same compound, but the dose, the ceiling and the record differMagnesium Glycinate — superior absorption sleep & muscle support.
Usual daily dose 200-600 mg, taken evening with or without food. The ceiling is 350 mg from supplements a day (NIH ODS). It is named as the suspect product in 379 FDA reports. Evidence grade A.
Magnesium Oxide — budget magnesium & laxative.
Usual daily dose 400-800 mg, taken divided doses with meals. The ceiling is 350 mg from supplements a day (NIH ODS). It is named as the suspect product in 379 FDA reports. Evidence grade A.
How these numbers are read
- The absorption score ranks forms of the same compound against each other. It is not a measured share of the dose — see how we derive it.
- Safety rating reflects tolerance at normal doses, not toxicity risk.
- Cost is per month at the typical daily dose, so a cheaper form taken at double the dose is not cheaper.
- Evidence level A means the form itself was studied, not just the parent compound.
Where to buy
Both forms deliver the same compound — pick by the numbers above, then check the label matches.
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Common questions
Which is better, Magnesium Glycinate or Magnesium Oxide?
Magnesium Glycinate absorbs better — 90% against 4%. Absorption decides how much of the dose actually reaches you, so it usually matters more than the milligrams printed on the label.
What is the difference between Magnesium Glycinate and Magnesium Oxide?
Both deliver the same active compound. They differ in how well the body takes them up, how they are tolerated and what a month costs: $25 against $8.
Can you take Magnesium Glycinate and Magnesium Oxide together?
You can, but there is rarely a reason to. Two forms of the same compound stack the same active dose, so the usual approach is to pick the better absorbed one and dose it properly.