“Magnesium” on a label doesn’t tell you much. The form it’s bound to changes how much your body can actually absorb and how it feels going down. Here’s the quick, science-backed version.
Magnesium oxide
Cheap and common, but poorly absorbed. It contains a lot of elemental magnesium on paper, yet studies consistently show low bioavailability, much of it passes through unabsorbed, which is also why it’s known for a laxative effect. Great value, not so great for topping up your levels.
Magnesium citrate
Bound to citric acid and notably more bioavailable than oxide. It’s well researched and widely used. At higher doses it can still have a gentle laxative effect, so it suits some people better than others.
Magnesium glycinate
Magnesium bound to the amino acid glycine. It’s well absorbed and tends to be gentle on digestion and glycine itself is associated with calm and sleep. That combination is why glycinate is a favourite for evening, wind-down use.
Why the form matters for sleep
If your goal is rest and recovery, you want a form your body absorbs efficiently and that won’t send you to the bathroom at midnight. A well-chosen, well-dosed magnesium supports the nervous system as you wind down — which is exactly the job it has to do at night. (More on that in Magnesium & Sleep Regulation.)
That’s the thinking behind NightShift™: a considered magnesium pairing, dosed to be felt, in flavours like Hot Cocoa and Biscotti that turn your wind-down into a ritual rather than a chore.
Get the form that works with your wind-down - Shop NightShift™.
Sources
Walker AF, Marakis G, Christie S, Byng M.
Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study.
Magnesium Research. 2003;16(3):183–191.
Ranade VV, Somberg JC.
Bioavailability and pharmacokinetics of magnesium after administration of magnesium salts to humans.
American Journal of Therapeutics. 2001;8(5):345–357.
Abbasi B, et al.
The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.
Journal of Research in Medical Sciences. 2012;17(12):1161–1169.
