UMF vs MGO:
Understanding Mānuka Honey Ratings
Information in this article shouldn't be considered medical advice. If you are considering taking manuka honey, propolis, royal jelly or bee pollen for their health benefits and are currently taking medication, please consult your doctor first.
What UMF Means
“UMF” stands for “Unique Mānuka Factor”, a quality and authenticity grading system developed within New Zealand specifically for manuka honey. This grading system is administered by the Unique Mānuka Factor Honey Association, an industry body that set the grading standards for its members and licenses the use of the UMF mark.
A UMF rating reflects a quality assurance system focused on potency, authenticity, shelf life and freshness. These properties are supported by independent quality tests of four key natural components:
- Potency: Methylglyoxal (MGO)
- Shelf Life: Dihydroxyacetone (DHA)
- Authenticity: Leptosperin (unique to the manuka tree)
- Freshness: Hydroxymethylfurfural (HMF)
Together these compounds help distinguish manuka honey from other honey types, and accurately measures the potency and lifespan of the active compounds.
UMF certification requires honey to be tested by independent laboratories and comply with additional standards relating to authenticity, traceability, and labelling. The UMF number itself (eg: UMF 15+) represents a verified profile containing a level of potency, rather than just measuring a single compound.
New Zealand’s regulatory definition of mono-floral manuka honey is set by the Ministry for Primary Industries (MPI). The UMF standard operates as an industry certification system that aligns with, but is separate from, MPI and their regulatory definition.
What MGO Means
MGO refers to methylglyoxal, a naturally occurring compound found within manuka honey, and is primarily responsible for its health-supporting properties. During testing, it is measured in milligrams per kilogram (mg/kg) and is often displayed prominently on products labels (eg: MGO 512)
MGO levels in manuka honey arice from the conversion of dihydroxyacetone (DHA), which is present in manuka nectar. This conversion occurs naturally over time and can continue even after the honey has been harvested.
An MGO value only communicates the concentration of methylglyoxal within the honey at the time of testing. It does not, on its own, verify the honey’s botanical origin, nor does it indicate whether other manuka-specific markers are present.
Why UMF Measures More Than MGO
Unlike an MGO rating on its own, a UMF rating is designed as a composite system to address both authenticity and its chemical profile. While MGO is one important marker in this, it is not unique to manuka honey and can be present in other contexts.
By testing for leptosperin, which is considered a stable manuka honey specific marker, and by assessing DHA alongside MGO, UMF testing provides a broader verification framework. This reduces the risk that a single value could be misinterpreted or manipulated.
How UMF and MGO Relate to Each Other
UMF and MGO are related, but they are not equal in value. Due to this difference in numbering on labels, it can be confusing if you don’t understand the purpose of each rating. As long as leptosperin and DHA markers exist in the honey, then as the MGO level gets higher, so does the UMF value.
- UMF 5+ = MGO 83
- UMF 10+ = MGO 261
- UMF 15+ = MGO 512
- UMF 20+ = MGO 826
- UMF 22+ = MGO 1000
- UMF 24+ = MGO 1120
- UMF 35+ = MGO 2190
MGO within manuka honey can increase over time as DHA converts, and decrease over time once the DHA has run out, and it can be influenced by storage conditions. All chemical measurements represent the state of the honey at the time of testing.
Why MGO-Only Labelling Can Be Misleading
MGO-only labelling can be quite misleading as it presents a single data point without the broader overall quality assurance context. While the MGO number itself may be accurate, it does not communicate whether the honey will remain true to label over time. I.e. has sufficient DHA present to refresh/recharge the MGO level during the declared shelf life of the honey. Additionally, the MGO labelled product does not convey anything about the amount of the bioactive component Leptosperin that is present. The UMF rating requires a specific level of Leptosperin to be present.
Which Rating System Is More Reliable
Reliability depends on what is being asked. Whether a label has UMF, MGO or both displayed, they are required to always be accurate. If the goal is to understand the concentration of methylglyoxal at the time of testing, then an MGO measurement provides that information directly.
However, if the goal is to provide overall quality assurance of the honey, i.e. is has been independently verified for authenticity, shelf life, freshness alongside the MGO potency, then the UMF rating is more thorough and reliable system.
UMF’s requirements for independent testing, defined thresholds, and ongoing compliance is intended to reduce ambiguity.
How Rating Systems Affect Price
While the rating system used on the label doesn’t directly affect the price, the actual grade itself does.
Higher levels of MGO in manuka honey are much rarer to obtain than the lower grades. Some of the highest-level MGO manuka honey (such as a UMF 35+ MGO 2190) is so rare it accounts for only 0.03% of all manuka honey ever harvested and tested in the last decade and more.
On top of this, to be able to use UMF ratings on labels, a company must be a registered member of the UMFHA which incurs significant investment.
However, it’s important to not simply assume that a higher-priced manuka honey guarantees its grade or verification. Always look for the rating on the label, ideally UMF, to ensure its grade and origin as an authentic New Zealand manuka honey.
