Picture this: you’re standing in the pharmacy aisle, staring at a wall of supplements. On one side, there are dozens of bottles of magnesium pills, all with different names like oxide, citrate, and glycinate. On the other, you see sprays and lotions promising a totally different approach.
You’re just trying to find something to help with your tight shoulders and restless sleep, but suddenly you’re faced with a dozen questions. Do the pills even work? Is the spray a gimmick? And why do some of them have a reputation for, well, disaster pants?
It’s one of the biggest points of confusion out there, and for good reason. The difference between swallowing your magnesium and spraying it on your skin isn't just a matter of preference; it's a huge difference in how your body actually gets and uses this vital mineral.
So, let's settle the debate. We’re going to walk through how each method works, bust some major myths, and give you the straight facts so you can choose the path that’s right for your body.
The idea behind a magnesium pill is simple. You swallow it, it travels through your digestive system, gets absorbed, and eventually makes its way to your cells. In theory, it’s a straightforward delivery system.
In practice, it’s more like sending your magnesium on an obstacle course.
The Problem: Not Much Makes It to the Finish Line
The single biggest issue with oral magnesium is absorption. Just because you swallow something doesn't mean your body can actually use all of it.
- The Form Matters (A Lot): This is where most people get tripped up. The cheap, common forms of magnesium you see in many basic supplements are often the least effective. Magnesium oxide, for example, is notoriously difficult for the body to break down. Studies show its absorption rate can be as low as 4%. That means 96% of what you swallow is doing almost nothing for your muscles and nerves.
- Better, But Not Perfect: More "bioavailable" forms like magnesium citrate or glycinate are definitely an improvement. But even then, you're often still losing a huge portion of the dose before it ever has a chance to work.
The Infamous "Laxative Effect"
So, what happens to all that unabsorbed magnesium? It doesn't just disappear. It continues its journey through your intestines, and this is where the trouble starts. Unabsorbed magnesium draws water into your colon, and the result is the classic, urgent, and unpleasant diarrhoea that gives oral magnesium its reputation.
This isn't really a side effect; it's a direct consequence of poor absorption. The more of a supplement your body can't use, the more likely it is to cause digestive chaos.
Myth Buster: Does Diarrhoea Mean You've Had "Enough"?
This is a dangerously persistent myth. You'll often hear people say, "take magnesium until you get diarrhoea, then back off the dose." The logic is that the laxative effect is your body's way of telling you it's full.
This is not true.
For most pills on the market, the laxative effect is simply a sign of rejection. It means you’ve overwhelmed your digestive system with a form it can't absorb, long before your cells have gotten what they need. It’s like a bouncer kicking people out of a club, not because the club is full, but because they don't have the right ticket to get in.
