Magnesium Supplement Buying Guide: Glycinate vs Citrate vs Oxide

Magnesium is involved in over 300 enzymatic reactions in your body, yet an estimated 50-75% of people don't get enough of it through diet alone. If you're considering supplementation, you've probably noticed the confusing array of magnesium types on the shelf.

Here's the thing: not all magnesium supplements are created equal. The form matters enormously — it affects absorption, effectiveness, side effects, and which health goals it serves best.

The Main Forms of Magnesium

Form	Absorption	Best For	Side Effects
Magnesium Glycinate	Excellent	Sleep, anxiety, general deficiency	Very few
Magnesium Citrate	Good	Constipation, general use	Mild laxative effect
Magnesium Oxide	Poor (~4%)	Budget, occasional constipation	Diarrhea likely
Magnesium Threonate	Good (brain)	Cognitive function, focus	Minimal
Magnesium Malate	Good	Energy, muscle pain	Minimal

Magnesium Glycinate: Our Top Pick

If you're buying magnesium for the first time, magnesium glycinate is the form we recommend for most people. Here's why:

• Highly bioavailable: Bound to glycine, an amino acid that actually supports calmness
• Gentle on stomach: Unlike oxide or citrate, it rarely causes digestive upset
• Great for sleep: Glycine itself has calming properties that support better sleep
• Raised magnesium levels effectively: Studies show it increases blood magnesium more reliably than other forms

Magnesium Citrate: Good for Budget-Conscious Buyers

Citrate is the second most common form and has its place. It's well-absorbed, affordable, and widely available. However, it has a natural laxative effect, which can be a pro or a con depending on your needs.

Choose citrate if: You occasionally struggle with constipation AND want to raise magnesium levels.

Avoid citrate if: You have a sensitive stomach or need a gentle daily supplement.

Magnesium Oxide: Skip It

Oxide is the most common form in cheap multivitamins, but it has abysmal absorption (~4%). Most of it passes through your digestive tract unabsorbed, which is why it's often used as a laxative rather than a true magnesium supplement.

We do NOT recommend magnesium oxide for raising your magnesium levels. Save your money and go with glycinate or citrate instead.

How Much Magnesium Do You Need?

The Recommended Dietary Allowance (RDA) is:

• Adult men: 400-420 mg/day
• Adult women: 310-320 mg/day
• Pregnant women: 350-360 mg/day

Most supplements provide 200-400mg per serving. Take it with food, ideally in the evening if you're using it for sleep support.

Our Final Recommendation

For most people, magnesium glycinate at 200-400mg per day is the sweet spot. It's gentle, effective, and supports both magnesium repletion and better sleep quality.