Every electrolyte powder on the shelf lists magnesium. Almost none of them tell you which kind — and the kind is what decides whether that magnesium does anything useful once it's in the glass. If you're trying to pick the best magnesium for an electrolyte drink, the milligram number on the front is the wrong thing to read first. The form named in the parentheses matters more.
Here's the short version, then the mechanism behind it.
Why the form of magnesium matters more than the dose
Magnesium is a workhorse mineral — a cofactor in more than 300 enzymatic reactions, including the ones behind muscle contraction and nerve signaling. Magnesium supports normal neuromuscular function. But your body can only use what it absorbs, and magnesium is sold bound to different partner molecules that change how much gets in and how your gut reacts on the way.
Two powders can both say "100 mg magnesium" and behave completely differently. The NIH Office of Dietary Supplements notes that some forms are far better absorbed than others, and that unabsorbed magnesium salts pull water into the intestine through an osmotic effect and can cause loose stools. Same number on the label, very different experience in your body.
The three forms you'll actually see
Nearly every electrolyte product uses one of these three. Knowing them turns a confusing label into a quick decision.
Magnesium oxide
Cheap, and it lets a brand print a big magnesium number because oxide is mostly magnesium by weight. The catch: it's one of the least absorbable forms, so a lot of it passes straight through. If a label just says "magnesium" with no form named, oxide is a common default — and a reason to keep reading.
Magnesium citrate
This one is more interesting, because it's genuinely well absorbed and dissolves cleanly, which is exactly why so many powders and ready-to-drink beverages reach for it. But citrate has a second job most labels won't mention: it's an osmotic laxative. It's the active ingredient in colonoscopy prep and in some over-the-counter constipation products, and it works by drawing water into the intestine.
At a single modest serving, most people won't notice. Stack a couple of servings on a hot day, or start with a sensitive gut, and that osmotic tug shows up — as urgency or loose stools. In a drink you're reaching for specifically to hold onto fluid, pulling water into the gut runs against the goal. Citrate isn't a bad molecule; it's just doing something in the background that works against what a hydration product is for.
Magnesium bisglycinate
Bisglycinate is magnesium chelated to two molecules of the amino acid glycine. It's well absorbed and — the part that matters for a drink — it's gentle, without the osmotic pull that gives citrate its laxative reputation. That's the form burbo uses, and it wasn't an accident.
What burbo puts in the stick, and why
Each burbo stick delivers 100 mg of magnesium as magnesium bisglycinate — 24% of the Daily Value, which makes it an excellent source of magnesium. We chose bisglycinate over the cheaper, tetchier options because a hydration drink should help you keep fluid, not send you looking for a bathroom.
The dose sits in a sensible place, too. The upper limit for supplemental magnesium is 350 mg a day, so 100 mg a stick leaves comfortable room: two sticks in a day is well within range, and three is the practical ceiling we'd suggest staying under. Each batch is third-party tested for heavy metals, so you know what's in the stick you're mixing.
Magnesium isn't working alone in there. The mineral that actually drives fluid retention is sodium, and burbo carries 327 mg per stick — enough to help your body hold onto the water you drink. In the beverage-hydration-index work by Maughan and colleagues (2016), drinks with meaningful electrolyte content stayed in the body longer than plain water. Sodium does the retention; magnesium supports neuromuscular function. Together they are the point of the drink.
How to read your own label in ten seconds
Whatever brand you're holding, find the form in parentheses after "magnesium":
- Oxide — big number, poor absorption. Be skeptical.
- Citrate — well absorbed, but osmotically active; fine in small amounts, easy to overdo across several servings.
- Bisglycinate or glycinate — well absorbed and gentle on the gut, which is what you want in something you drink for hydration.
And remember the whole-drink rule: one stick per full bottle of water, every time. More magnesium — or more of any electrolyte — never means a stronger drink. It just means more fluid to carry it.
Choosing the best magnesium for an electrolyte drink
Look past the front-of-pack number and find the form. Oxide is filler you won't absorb; citrate is well absorbed but works against a hydration product's whole purpose if you lean on it; bisglycinate gives you the magnesium without the gut drama. burbo uses bisglycinate on purpose — 100 mg, an excellent source, in a stick built to help you hold onto water rather than lose it.
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. How this article was researched and written: our editorial standards.