Last reviewed October 27, 2026 by the Cellovi team.
The short answer
Every form delivers the same mineral. What changes is how much your body absorbs and how your stomach handles it. In human studies, organic forms such as citrate are absorbed better than magnesium oxide; citrate is also a known laxative, and glycinate is a gentle option. Cellovi Magnesium Glycinate gives 275 mg of elemental magnesium in three evening capsules, below the 350 mg upper limit for supplements.*
Why magnesium matters
Magnesium is a cofactor in more than 300 enzyme systems, including those that run muscle and nerve function. Yet 48% of Americans get less magnesium from food and drink than they need (NIH Office of Dietary Supplements, from national survey data, 2013 to 2016).
| Adults 31 and over | Amount per day |
|---|---|
| Recommended intake, men | 420 mg from all sources |
| Recommended intake, women | 320 mg from all sources |
| Upper limit from supplements | 350 mg (food does not count toward it) |
How do the forms compare?
A label lists two numbers: the compound (for example 2,500 mg magnesium glycinate) and the elemental magnesium inside it (275 mg). Always compare elemental magnesium.
| Form | What human studies show | Good to know |
|---|---|---|
| Oxide | About 4% absorbed in one study (Firoz and Graber, 2001). In a 60-day trial, it did not raise blood magnesium more than placebo (Walker et al., 2003). | The most common form in low-cost tablets, because it packs the most magnesium per milligram. |
| Citrate | Raised blood and urine magnesium more than oxide (Lindberg et al., 1990; Walker et al., 2003). | Also sold as a saline laxative (MedlinePlus), so larger doses can loosen stools. |
| Glycinate (bisglycinate) | In a 2025 trial of 155 adults with poor sleep, 250 mg a day for 4 weeks improved sleep more than placebo on the trial's main measure. Side effects were also fewer than with placebo (Schuster et al., 2025). | Magnesium bound to the amino acid glycine. Gentle on the stomach, which is why we chose it for an evening routine. |
| L-threonate | In a 6-week trial of 100 adults, 145 mg a day improved a cognition score (Lopresti and Smith, 2025). | The case for better brain uptake comes mostly from animal studies. Low magnesium per capsule. |
| Malate | Little human data on its own. | Magnesium bound to malic acid. |
Does magnesium help with sleep?
Magnesium's role in normal muscle and nerve function is long established. Studies of sleep itself point the same way: a review of three trials in older adults found people fell asleep about 17 minutes faster on magnesium (Mah and Pitre, 2021). The 2025 glycinate trial above found better sleep than placebo on its main measure. So we describe magnesium as support for relaxation and sleep, never as a sleeping pill.*
After exercise. In a small trial, magnesium glycinate at 350 mg a day for 10 days eased muscle soreness after exercise and improved how recovered people felt, as summarized in a 2024 review of magnesium and exercise recovery (Tarsitano et al., 2024).*
Who should check with a doctor first
- Anyone with kidney disease, because the kidneys clear extra magnesium.
- People taking bisphosphonates for bone: take them at least 2 hours apart from magnesium.
- People taking tetracycline or quinolone antibiotics: take the antibiotic 2 hours before, or 4 to 6 hours after, magnesium.
- People on diuretics or long-term acid-reducing medicines (PPIs), which can change magnesium levels.
Source for these points: NIH Office of Dietary Supplements.
Why Cellovi uses glycinate
Cellovi Magnesium Glycinate gives 275 mg of elemental magnesium from 2,500 mg of magnesium glycinate in three capsules, taken in the evening. It is gentle on the stomach, it fits under the supplement upper limit, and it anchors our Calm & Sleep Protocol, paired with morning ashwagandha.*
Common questions
Which form of magnesium is best for sleep?
Of the forms we compared, glycinate has the newest sleep trial: in 155 adults with poor sleep, 250 mg a day for 4 weeks improved sleep more than placebo on the trial's main measure. It is also gentle on the stomach, which is why Cellovi Magnesium Glycinate is taken in the evening.*
How much magnesium do I need a day?
Adults 31 and over need 420 mg (men) or 320 mg (women) a day from all sources. The upper limit from supplements is 350 mg, and food does not count toward it. Cellovi gives 275 mg of elemental magnesium in three capsules.
Is magnesium oxide worth taking?
It packs the most magnesium per milligram, which is why it is common in low-cost tablets. But only about 4% was absorbed in one study, and in a 60-day trial it did not raise blood magnesium more than placebo.
Will magnesium upset my stomach?
It depends on the form. Citrate is also sold as a laxative, so larger doses can loosen stools. Glycinate is a gentle option.
Sources
- NIH Office of Dietary Supplements. Magnesium fact sheet for health professionals, updated January 2026.
- Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnesium Research, 2001.
- Walker AF et al. 60-day randomized trial of magnesium citrate, amino-acid chelate and oxide. Magnesium Research, 2003.
- Lindberg JS et al. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition, 1990.
- MedlinePlus (US National Library of Medicine). Magnesium citrate.
- Schuster J et al. Randomized trial of magnesium bisglycinate in adults reporting poor sleep. Nature and Science of Sleep, 2025.
- Lopresti AL, Smith SJ. Randomized trial of magnesium L-threonate in adults. Frontiers in Nutrition, 2025.
- Mah J, Pitre T. Systematic review and meta-analysis of oral magnesium and sleep in older adults. BMC Complementary Medicine and Therapies, 2021.
- Tarsitano et al. Systematic review of magnesium supplementation and exercise recovery. Journal of Translational Medicine, 2024.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.