Magnesium (L-Threonate & Glycinate)

Glycinate is bound to the amino acid glycine and is chosen for general magnesium repletion, sleep, and relaxation, the everyday role magnesium plays in the body. L-threonate is bound to threonic acid and was developed specifically around research suggesting it crosses into brain tissue more readily, with human trials looking at cognitive outcomes like working memory alongside sleep. They're both magnesium, but the choice comes down to whether you want the general-purpose form or the brain-targeted one.

No, despite the similar-sounding names. Magnesium L-threonate is a mineral compound, magnesium bound to threonic acid, researched for reaching brain tissue and supporting memory and sleep. L-theanine is a completely different amino acid found in tea, used for calm focus, often alongside caffeine. If you're looking for L-theanine products, you'll find them in our L-Theanine collection instead.

Dose for dose, they're nearly identical: 145 mg versus 144 mg of elemental magnesium, both from the same patented Magtein ingredient. The real differences are price and capsule count. Designs for Health is the original practitioner-channel brand behind the ingredient, while Sports Research delivers essentially the same active dose at less than half the daily cost.

The Designs for Health complex delivers a higher, fixed 300 mg dose per serving and works out to a lower cost per milligram, since it's buffered with a small amount of magnesium oxide alongside the glycinate chelate. The Metagenics tablets are pure bisglycinate with no oxide at all, dosed at 100 mg per tablet, so you can take one for a light dose or two for a fuller one. Pick Designs for Health if you want the highest single dose. Pick Metagenics if you want flexibility and a lower total spend.

You can, but add up your total elemental magnesium first rather than stacking two full servings. Combined intake above roughly 350 mg per day from supplements raises the odds of digestive discomfort. If you want both the cognitive and the sleep or relaxation benefits, consider a partial dose of one or both instead of two full servings.

Yes, though it's not part of this collection specifically since it's a three-form blend rather than a pure L-threonate or glycinate product. Our Sports Research Triple Magnesium Complex combines glycinate with malate and taurinate, and is positioned as an any-time-of-day magnesium rather than one leaning toward evening use. Worth a look if neither the brain-targeted nor the sleep-forward framing here fits what you're after.

An evening dose is a sensible default across all four if sleep or relaxation is part of your goal, since magnesium's role in GABA and melatonin pathways makes that a logical time to take it, though splitting the dose across the day works too. Give it two to four weeks of consistent daily use before judging it. The one exception is Metagenics, where our own team noticed a faster subjective effect within 30 to 60 minutes, though the deeper, ongoing benefits still build over the same longer timeframe as the others.