Magnesium glycinate has fast become one of the most popular types of magnesium, known for its high absorption and gentle effects on digestion. But did you know that not all magnesium glycinate supplements are created equal?
In the UK, many brands sell buffered magnesium glycinate, a cheaper and less bioavailable version that contains added magnesium oxide. Unfortunately, this is often not clearly disclosed on product labels, leaving customers unaware of what they’re actually taking.
In this article, we’ll break down the key differences between buffered and non-buffered magnesium glycinate, how to spot the difference, and why it matters.
What is Buffered Magnesium Glycinate?
Buffered magnesium glycinate is a blended form of magnesium glycinate that has been mixed with magnesium oxide—a cheaper, less absorbable type of magnesium. This is done to artificially increase the elemental magnesium content, making the supplement appear stronger on the label.
At first glance, buffered magnesium glycinate seems like a better deal due to it’s higher elemental magnesium content—typically 20% or more. However, this comes with significant drawbacks:
- Contains Magnesium Oxide – Magnesium oxide is poorly absorbed by the body, with an absorption rate as low as 4%, meaning much of it passes through your system without providing real benefits.
- Higher Risk of Digestive Issues – Due to the presence of magnesium oxide, buffered magnesium glycinate is more likely to cause stomach discomfort, bloating, and diarrhea.
- Misleading Strength Claims – Many brands selling buffered magnesium glycinate fail to disclose that their product contains magnesium oxide, leading consumers to believe they are getting pure, fully chelated magnesium glycinate when they are not.
Buffered magnesium glycinate is widely used in the supplement industry as a cost-cutting measure, allowing brands to offer a high-magnesium supplement at a lower price—but at the expense of quality and effectiveness.
What is Non-Buffered Magnesium Glycinate?
Non-buffered magnesium glycinate is the pure and proper form of magnesium glycinate, free from any added magnesium oxide. It contains only fully chelated magnesium glycinate (also known as magnesium bisglycinate) where each magnesium molecule is bound to two glycine molecules, ensuring superior absorption and bioavailability.
Unlike buffered versions, non-buffered magnesium glycinate is designed for maximum effectiveness without unnecessary fillers or dilutions. It typically contains an elemental magnesium content of 10–14%.
Why Choose Non-Buffered Magnesium Glycinate?
- Superior Absorption – Fully chelated magnesium bisglycinate is one of the most bioavailable forms of magnesium, ensuring your body absorbs and utilises it effectively.
- Gentle on Digestion – Unlike magnesium oxide, non-buffered magnesium glycinate is easier on the stomach, reducing the risk of digestive discomfort.
- Trusted Purity – With no hidden magnesium oxide, you get exactly what you’re paying for—high-quality magnesium glycinate without dilution.
By choosing non-buffered magnesium glycinate, you ensure maximum effectiveness, better absorption, and a supplement that genuinely supports your well-being—without the hidden downsides of buffered alternatives.
How to Spot Buffered Magnesium Glycinate
With many brands failing to disclose when their magnesium glycinate is buffered with magnesium oxide, it’s important to know how to identify it yourself. Fortunately, there are two key indicators that make it easy to spot:
- Elemental Magnesium Content – Buffered magnesium glycinate typically contains 20% or more elemental magnesium. If a product label states 300mg of magnesium from 1,500mg of magnesium glycinate (20%), it’s a clear sign that magnesium oxide has been added. In contrast, pure, non-buffered magnesium glycinate falls within the 10-14% range of elemental magnesium.
- Capsule Strength – The largest capsule commonly used in the UK (size 00) can hold 750-850mg of powder. Even with the strongest non-buffered magnesium glycinate (14% elemental magnesium), the most you can fit per capsule is around 105-119mg of magnesium. If a product claims 150mg or more per capsule, it’s almost certain to contain a buffered ingredient with magnesium oxide.
If you’re unsure, don’t hesitate to check the label carefully or contact the brand directly. Reputable companies should be transparent about their ingredients and formulation.
The Bottom Line
When it comes to magnesium glycinate supplements, not all products are created equal. While buffered magnesium glycinate may appear to offer a higher magnesium content, the addition of magnesium oxide reduces its absorption and effectiveness—often without clear disclosure on the label.
Choosing non-buffered magnesium glycinate ensures you’re getting maximum bioavailability, gentle digestion, and a supplement free from magnesium oxide. By understanding the difference and knowing what to look for, you can make ensure you are buying a high-quality product.