Manuka Honey 101: What the Numbers Really Mean (UMF™ & MGO Explained)

Standing in front of a shelf of Manuka honey can be confusing. Jars are labelled with numbers like UMF™, MGO, or sometimes both — but what do those numbers actually mean, and how do you know which one to choose?

At Happy Valley, we believe understanding Manuka honey shouldn’t require a chemistry degree. This guide breaks down the most common grading systems, explains how they’re used, and helps you make sense of the numbers on the label — simply and transparently.

Manuka honey is a unique variety of honey produced by bees that collect nectar from the Manuka tree (Leptospermum scoparium), a native plant found only in New Zealand. Unlike standard table honey, Manuka honey is defined by its botanical origin and the naturally occurring compounds that come from Manuka nectar.

Because the Manuka tree flowers for only a short period each year and often grows in remote areas, genuine Manuka honey is naturally limited in supply. This rarity, combined with strict testing requirements, is what sets it apart from other honeys.

UMF™, or Unique Manuka Factor, is a trademarked certification system used to identify genuine New Zealand Manuka honey. Rather than relying on a single measurement, the UMF™ system assesses multiple naturally occurring markers that are characteristic of Manuka honey.

To carry the UMF™ mark, each batch must be independently tested and verified by an accredited laboratory. These tests help confirm the honey’s authenticity, quality, and classification before it is graded and labelled.

UMF™ certification focuses on transparency and traceability — giving consumers confidence that what’s inside the jar matches what’s stated on the label.

MGO, short for methylglyoxal, refers to the measurement of one specific naturally occurring compound found in Manuka honey. MGO is expressed as a number (for example, MGO 263+), indicating the concentration of that compound in milligrams per kilogram.

Some brands choose to display MGO only, while others show both UMF™ and MGO on their labels. This is because the two systems are related but serve slightly different purposes:

• MGO highlights the level of one compound
• UMF™ reflects a broader, multi-marker certification

Seeing one or both on a jar doesn’t mean one system is “better” than the other — they’re simply different ways of communicating how the honey has been graded.

While UMF™ and MGO are often discussed together, they aren’t interchangeable. UMF™ grades correspond to minimum MGO levels, but they also take additional markers into account as part of the certification process.

That’s why two jars with similar MGO numbers may not necessarily carry the same UMF™ grade. Understanding this relationship can help you better interpret labels and compare products with confidence.

It’s a common misconception that the highest number is always the best choice. In reality, the right Manuka honey grade depends on how you plan to enjoy it, how often you’ll use it, and your personal flavour preference.

Lower UMF™ grades tend to have a milder taste and are often chosen for regular, everyday enjoyment, while higher UMF™ grades offer a more intense flavour and are produced in smaller quantities. Neither is “better” — they simply suit different preferences and occasions.

If you’re unsure where to start, a guided approach can make choosing much easier.

Manuka honey doesn’t need hype or exaggerated claims to stand out. Its value lies in its origin, its rarity, and
the systems in place to protect its authenticity. By understanding what UMF™ and MGO mean — and how they’re used — you can choose Manuka honey that suits your taste, routine, and expectations with confidence.

For more guides, explanations, and tools to help you navigate Manuka honey, explore our education hub below.

Manuka Education Hub