The UK's Top 5 Magnesium Brands Are Lying To You

The Trick: They're Filling Your Capsules With Magnesium You Can't Absorb

Here's the part nobody tells you. There are lots of different forms of magnesium, and they are not all the same.

The two you need to know about are magnesium glycinate and magnesium oxide. One is the gold standard. The other is the cheapest, worst form on the market. And brands have figured out a sneaky way to use the bad one to make their labels look like the good one.

So why would brands use the bad one?

Here's the clever bit. Magnesium oxide is 63% elemental magnesium by weight. Magnesium glycinate is only about 14%. That difference is everything.

Imagine you're a brand. You want to put a big "400mg of magnesium!" claim on the front of your bottle, because that's what sells. With pure glycinate, hitting 400mg of elemental magnesium would mean cramming nearly 3,000mg of compound into each serving. That's a huge, expensive capsule.

But if you secretly mix in some cheap magnesium oxide, you can hit that 400mg number on the label using a fraction of the material, and at a fraction of the cost. The label looks impressive. The customer feels reassured. Your margins go up. Everyone wins.

Except your body. Because the oxide portion is barely absorbed. You might be swallowing "400mg of magnesium" and only actually using a tiny bit of it.

This trick has a name in the industry. It's called "buffering". And once you know that word, you start spotting it everywhere. Some brands are even brazen enough to print "buffered" right on the label, Free Soul does this. They're not technically lying. They're just betting that you don't know what the word means.

Here's The Proof, In Their Own Numbers

You don't have to take my word for it. The maths gives them away.

Let's take Nutrition Geeks, currently the best-selling supplement on all of Amazon UK. Over 260,000 bottles a month. Their label says each serving gives you 384mg of elemental magnesium from a blend of three forms: glycinate, malate, and citrate.

Here's what that's physically possible to deliver, based on the molecular weight of each compound:

The lab confirmed the bottle contained 385mg of elemental magnesium, almost exactly what the label said. So where's that extra 117mg coming from? It can only be magnesium oxide. There's no other explanation that doesn't break the laws of chemistry.

To double-check this wasn't me being paranoid, my team rang the UK's biggest magnesium raw material supplier. He confirmed it on the phone in about ten seconds: it's physically impossible to get above ~14% elemental magnesium from glycinate alone. And he said he has no idea why it's allowed.

And it's not just Nutrition Geeks. I ran the same maths on every single product I tested. The result was worse than I expected.

Free Soul does it too, and they're so confident no one will notice that they actually print the word "buffered" on the bottle. Their blend of 1,283mg of "magnesium glycinate" somehow yields 385mg of elemental magnesium, which is 30% elemental, more than double what's chemically possible from glycinate alone.

Straight from the Free Soul label. The word "buffered" is the industry code for "we've cut this with magnesium oxide".

Four out of five. Every single capsule product on the UK magnesium bestseller list is doing the same trick. The only one that isn't buffering is a kids' gummy with a dose so small it's barely worth taking.

That's the real problem. This isn't a few bad apples. It's the entire category. The brands at the top of Amazon are the ones who figured out the trick, and they're crushing the ones who didn't, because there's no consequence for any of it. Nobody is testing. Nobody is enforcing. The shelves have been quietly poisoned.

The Only Way To Know What's In A Supplement Is To Test Every Single Batch

Here's the dirty secret of the supplement industry: even brands that "test their products" usually only do it once.

They send their first production run to a lab, get a clean certificate, then quietly use that single test as marketing for the next two years, even though every batch produced after it could be completely different. Different ingredient suppliers. Different raw material lots. Different machine calibrations. Different fill weights. The bottle that lands on your doorstep eighteen months after the original certificate might bear no relationship to what was actually tested.

That's why we do something almost no one else in this industry does. We test every single batch. Not the first one. Not a sample of them. Every. Single. One.

Most brands won't do this because it's expensive, slow, and occasionally embarrassing when something has to be scrapped. We do it because it's the only honest way to sell something you're asking people to put in their bodies every day.

And we've now applied the exact same approach to magnesium. Pure magnesium glycinate. No oxide. No buffering. No hidden filler. Because we refuse to buffer, we can't shrink the dose into a single tiny capsule like everyone else does. So a full serving is 4 capsules, and each bottle holds 120 capsules, giving you 338mg of real, properly absorbed elemental magnesium per serving from 2,600mg of pure glycinate. The label and the bottle finally match.