What Is UMF, MGO, KFactor, AMHA? Manuka Honey Rating Systems Explained

What Makes Manuka Honey Unique?

Manuka honey is very different to regular honey.

It contains unique compounds that give it medicinal properties, and the potency of these properties depends on the honey's production, processing and purity.

As a result, all high quality manuka honeys are graded.

Manuka honey grading is important because there are many fake manuka honeys around today. Grading is a way to validate a manuka honey's potency, authenticity, purity, shelf life and freshness.

Manuka honey is graded with a collection of unique Manuka Honey rating systems, but before we can break down the grading system, we need to understand exactly what they are measuring.

There are several components that make Manuka Honey unique:

MGO

What is the meaning of MGO when it comes to manuka honey? This is the most well-known component of manuka honey, which stands for methylglyoxal. This is the compound that gives manuka honey its strong antibacterial properties (study here). When people talk about "manuka honey strength", they're usually referring to MGO level.

DHA

The second unique ingredient of Manuka Honey is DHA or dihydroxyacetone, is also essential in a good manuka. The production of MGO is dependent on high DHA levels in the manuka flower, and therefore a high DHA level is usually a precursor of high levels of MGO.

NPA

The third unique ingredient of Manuka Honey is NPA or non-peroxide activity, and is what brings it all together.

For centuries, regular honey has been known to have some antibacterial activity due to the presence of hydrogen peroxide. However, researchers were stumped when manuka honey seemed to have much stronger antibacterial action, but the peroxide levels were not significantly higher. Eventually, they discovered MGO was responsible for manuka honey's non-peroxide activity.

 NPA is important because many of the proven health benefits of manuka honey is dependent on the presence of NPA. Potency of the honey is highly dependent on this. Honeys with low or no NPA are generally considered low quality Manuka Honey, and honeys with high levels of NPA are considered high quality Manuka Honey. 

Leptosperin

Leptosperin is the final piece of the Manuka Honey puzzle. It's a compound found in manuka honey that you won't find in any other type of honey.

This is often used as a marker to determine if its genuine Manuka Honey. If leptosperin is unable to be found, it is unlikely the honey is authentic Manuka honey.

The above four compounds are what determine the quality of a good Manuka Honey, and are used to determine a Manuka Honey rating. Of course there are other measurements you can make, but the ones above are unique to Manuka Honey and the most important to look for.

Manuka Honey Grades Explained:

Grading is how we measure the quality of manuka honey with a quantitative framework. Below we explain the main manuka honey rating systems that are in use today:

UMF – Unique Manuka Factor

What is UMF?

UMF stands for Unique Manuka Factor.

This is a grading system developed by the UMF Honey Association in New Zealand, where the manuka plant originates from. Most established New Zealand manuka honey producers use the Manuka Honey UMF system.

Non-peroxide activity

NPA, or non-peroxide acitivity, is central to the UMF grading system. As we said earlier, the potency of any manuka honey is highly correlated with NPA. Without NPA, the honey is simply considered low grade manuka honey. The actual UMF grade on the honey jar itself corresponds directly to the NPA. Therefore if the NPA level is 15, the honey will be marked “UMF 15”.

DHA and MGO

UMF also measures DHA (dihydroxyacetone) and MGO (methylglyoxal) levels. DHA and MGO are what give manuka honey its antibacterial activity, and go hand-in-hand (DHA is a precursor to MGO). 

Leptosperin

Additionally, to achieve a UMF grading, the honey must test positive for the presence of leptosperin to ensure honey has been produced from real manuka flowers.

HMF

The final part of UMF grading is a test for HMF or Hydroxymethylfurfural. HMF concentrations increase under excessive heat and prolonged storage times. In some cases, heat can be used to accelerate the conversion of DHA to MGO fraudulently. To secure a UMF rating, the HMF content after processing should not be more than 40 milligrams per kilogram to ensure the levels of MGO and DHA has not been manipulated by heating.

Without satisfying all five of these requirements, a manuka honey is not qualified to receive a UMF grading.

There is no official highest UMF rating for Manuka Honey, but it is rare to see Manuka Honey achieve a rating above 30, at least for consumer use. The highest rating we know is the UMF 28+ product from New Zealand Honey Co.

UMF is the most comprehensive manuka honey grading system in place today and considered the best indicator of overall antibacterial quality, purity, and authenticity. 

If you are looking for UMF certified Manuka Honey brands, you can see all current members of the UMFHA here.

UMF Grading Requirements

MGO rating system

The Manuka Honey MGO rating system is less complex than UMF, and only measures the level of MGO.

What is MGO? 

MGO is an abbreviation for Methylglyoxal, which is the naturally occurring compound that comes as a result of DHA in the Manuka flower. MGO contributes largely to Manuka's Honey's antibacterial mechanisms.

The MGO number tells you how much MGO is present in the jar of honey, so the higher the MGO rating, the higher the grade of honey.

There are two things to be aware of with MGO gradings: 

One, the level of MGO can change over time, so the amount of MGO in your honey when it was packed and the level when you buy and consume it may be different.

Second, MGO is also not solely responsible for Manuka Honey’s antibacterial properties – there are other compounds that contribute to how potent a particular manuka is. Therefore when it comes to UMF vs MGO, MGO is less reliable than a UMF grading, but can still be somewhat helpful in determining quality.

The MGO grading system was pioneered by Manuka Health in 2008.

KFactor by Wedderspoon

What Is KFactor?

Manuka Honey KFactor is a grading system invented by the company Wedderspoon.

The system is based on five key factors that Wedderspoon has chosen, based on New Zealand's agricultural ministry standards. They are:

1. Raw honey and unpasteurized
2. Non GMO verified
3. Produced and packaged in New Zealand
4. Free of glyphosate pesticides and antibiotics
5. Traceability from Hive to Home

KFactor comes with two gradings: Kfactor 16 and KFactor 12.

However, the numbers are insignificant and they could just as easily have been called KFactor 1 and KFactor 2. 

KFactor16 is Wedderspoon's monofloral Manuka Honey, meaning the honey is wholly made from the Manuka flowers.

KFactor12 is Wedderspoon's multifloral Manuka Honey, meaning the honey is a blend of Manuka flower pollen and other pollens as well. In other words, it's not a pure Manuka Honey but a Manuka and non-Manuka blend.

The main criticism of the KFactor system is that it doesnt test the most important components of Manuka Honey, those being NPA, MGO, DHA or leptosperin levels.

No company other than Wedderspoon has adopted this rating system as of yet.

AMHA - Australian Manuka Honey Association

The AMHA (Australian Manuka Honey Association) is a bit like the Australian equivalent to New Zealand's UMF.

AMHA has its own authenticity grading system for Manuka Honey produced inside Australia.

Their grading system is much simpler than the UMF system and essentially only has two grades - one for honeys with MGO content above 85 mg/kg, and one for honeys that have below.

The AMHA allows for Manuka honey to be pure monofloral Manuka (which they define as having ≥ 50% of the nectar derived from one floral source, or a multifloral Manuka blend that also contains nectar collected by the bees from other floral sources. 

All honey defined and labelled as Australian Manuka and carrying the Australian Manuka Honey Association (AMHA) Mark of Authenticity logo, must be produced in Australia, and be tested by an independent approved laboratory to ensure it contains the following criteria when packed. 

Specifically, the two grades are as follows:

To bear the ‘Authentic’ mark, products must be tested to contain at least:

• ≥ 85 mg/kg (or ppm) methylglyoxal (MGO)
• ≥ 170 mg/kg (or ppm) dihydroxyacetone (DHA)

To bear the ‘Authorised’ mark, products must be tested to contain at least:

• ≥ 30 mg/kg (or ppm) methylglyoxal (MGO)
• ≥ 60 mg/kg (or ppm) dihydroxyacetone (DHA)

As you can see, the AMHA grading system is far less elaborate than the UMF system, which tests for all four compounds (MGO, DHA, leptosperin and NPA) and grades them on a sliding scale, whereas the AMHA system is simply a "yes or no" system based on MGO and DHA content.

It also requires a lower potency in general. As an example, the UMF grading system requires an MGO of 83 mg/kg just to get a UMF 10  grade:

That is almost the same MGO requirement (85mg/kg) for the AMHA's top "Authentic" grade.

Therefore, you could conclude that any "AMHA Authentic" honey is about the same potency as a UMF 10+ (possibly higher, but there's no way to know for sure).

Therefore, we believe the UMF grading system offers a much more valuable indication of potency.

You can read more about the AMHA grading system here.

Comparing manuka honey grading systems

We generally recommend Manuka Honey buyers to stick with UMF certified brands, as it is the most reliable grading system. MGO, KFactor and AMHA are less thorough, and do not require certification from the UMF Association.

However, it can be helpful to compare grades as this makes it easier to compare products.

The table below will give you a (loose) comparison between UMF gradings, MGO gradings and KFactor scores.

For example, using this MGO chart you can see that a UMF 10 grade is the equivalent of an MGO 100 grade.

Or to convert KFactor16 to MGO, the chart will tell you an approximate range of 263-514 (since KFactor doesn't give MGO levels, exact comparisons aren't possible).

Similarly, KFactor16 to UMF will equal an approximate range of UMF 10-15.

Manuka Honey Grading Chart

UMF vs MGO

When choosing between UMF and MGO graded honey, the choice is easy. MGO grades only refer to MGO content, whereas UMF honey refers to MGO content as well as DHA, leptosperin and NPA - all indicators of antibacterial potency. Therefore, a UMF grading gives a better indication of quality than an MGO rating.

UMF vs AMHA

An AMHA grading does not specifically quantify the levels of compounds in each honey, it simply gives you a "yes or no" answer on whether its real manuka honey. Therefore, it's not possible to determine if one "AMHA Authentic" honey is of higher quality than another. For this reason, we always recommend opting for UMF graded honeys, especially at the higher price points.

KFactor vs MGO

If you a trying to decide whether to purchase MGO or KFactor graded honeys, we would recommend going with MGO. While KFactor does test "authenticity" to some degree, it does not test for levels of MGO, which is what will give the manuka honey the antibacterial activity you are looking for.

KFACTOR VS UMF

KFactor is undoubtedly an inferior grading system to UMF. Since UMF tests for all the necessary components of manuka honey potency, getting a UMF graded product means you can have absolute confidence the manuka honey is of high purity and potency. If your budget allows, definitely favor UMF products over KFactor.

If you are looking to purchase Manuka Honey, we recommend checking out our list of recommended brands.