UMF Manuka Honey vs KFactor vs Active vs MGO – Which Can I Trust?

With the growing popularity of Manuka honey, a number of grading systems have been created to convey the quality of the honey in the jar. UMF Manuka honey, KFactor, MGO, and Active/Bio Active are some of the most popular.

With so many grading systems it can be difficult to know which ones to trust. This article will help you spot low quality Manuka honey masquerading as the real deal.

If you’ve been looking around for Manuka honey, you’ve probably seen a variety of Manuka grading systems:

  • UMF 10+
  • KFactor 12
  • Bio Active 24+
  • MGO 550+

These grading systems are typically a few letters followed by a number ranging from 5+ to 30+.


That probably means the grading systems are all the same and a 10+ UMF Manuka honey is basically the same as a KFactor 12 Manuka honey, right?

Unfortunately, you’d be wrong.

Each of these grading systems has a different idea (sometimes a very different idea) of what ‘quality’ is. Comparing a 10+ UMF Manuka honey to a KFactor 12 Manuka honey is like comparing apples to oranges.

Purchasing Manuka honey without understanding the grading system on the label is a great way to end up with an orange when what you really wanted was an apple.

We’ll dive into each of the most popular Manuka honey grading systems and let you know what they mean. We’ll also let you know which grading systems you can trust and which ones are downright misleading.

Before we look at individual grading systems, we first need to take a closer look at Manuka honey and what makes it so special.

Hydrogen Peroxide in Honey

You may be familiar with the fact that honey has been used for medicinal purposes for thousands of years. All honey can exhibit antibacterial activity. You may be surprised, however, to learn that the antibacterial activity is due to hydrogen peroxide in the honey.

Yep, the same stuff you put on cuts and scrapes as an antiseptic.

Small amounts of hydrogen peroxide occur organically in honey due to glucose oxidase. Glucose oxidase is an enzyme that is added to flower nectar by honey bees to break down glucose sugars. A byproduct this interaction is hydrogen peroxide.

What Makes Manuka Honey Special?

Ok, now you’re wondering “if all honey has antibacterial activity, what makes Manuka so special?”

First of all, while all honey in the hive starts with antibacterial activity, they don’t all have it once it’s in the jar. Hydrogen peroxide is very sensitive to heat. Most honey producers use heat to extract honey from the honeycomb and to pasteurize it. Heating the honey severely degrades the hydrogen peroxide and the honey’s antibacterial activity is similarly degraded.

Hydrogen peroxide also breaks down when exposed to an enzyme found in saliva and blood. Those bubbles you see when you pour hydrogen peroxide on a cut is the peroxide breaking down. After it breaks down, it loses it’s antibacterial activity.

Secondly, and more importantly, in 1981 researchers from the New Zealand University of Waikato discovered that even after the hydrogen peroxide in Manuka honey was neutralized, it still exhibited strong antibacterial activity. This antibacterial activity, referred to as as non-peroxide activity (NPA), distinguishes Manuka from all other honeys and is why Manuka honey is so sought after.

Manuka’s Unique Non-Peroxide Activity

After nearly 30 years, researchers we able to identify methylglyoxal (MGO) as the active ingredient that is responsible for Manuka’s non-peroxide activity. Methylglyoxal occurs naturally in Manuka honey as dihydroxyacetone (DHA), an organically occurring compound found in Manuka flower nectar, spontaneously dehydrates.

While most honey contains small amounts of MGO (typically 0 to 7mg/kg), Manuka honey can contain more than 100 times the MGO found in normal honey.

What makes methylglyoxal special is that it’s resistant to heat and it does not degrade when exposed to saliva and blood like hydrogen peroxide does making it much more effective.

Not All Manuka is Created Equal

After Manuka’s unique NPA was first identified in 1981, researchers ran into issues trying to study this activity because certain batches of Manuka honey exhibited NPA while others didn’t. Decades later, after Manuka’s NPA was attributed to MGO, researchers discovered that not all Manuka honey contained significant levels of MGO.

Not all Manuka honey has non-peroxide antibacterial activity.

This has lead to confusion for consumers that assume all Manuka honey has the powerful antimicrobial properties that Manuka has become famous for. Some unscrupulous honey producers have taken advantage of this confusion and marketed their Manuka honey in ways that obscure the non-peroxide activity of their honey.

This is why it’s so important to know which Manuka honey grading systems are reliable and which ones aren’t.

What to Look for in Manuka Honey Grading Systems

When you’re shopping for a jar of Manuka honey the big question you should ask is:

Does this honey have non-peroxide activity and how strong is it?

The best Manuka honey grading systems will focus on conveying the strength of the non-peroxide activity of the honey. While purity of the honey is a concern, it becomes less important if you know the NPA of the honey. The reason for this is that high levels of NPA are only found in Manuka honey. So, if the honey has a high level of NPA, you can be confident that it’s genuine Manuka honey.

Grading systems that report only on the purity of the honey are not useful because we know that not all Manuka honey has NPA.

Also, systems that report on the ‘activity’ of the honey as a whole (both peroxide and non-peroxide activity) can be very misleading. These grading systems obscure the NPA of the honey. It’s often found that when when these honeys are independently tested, they exhibit very little NPA if any at all.

UMF Manuka Honey

UMF stands for Unique Manuka Factor and is one of the best grading systems out there. It’s run by the Unique Manuka Factor Honey Association (UMFHA), which is a third party New Zealand organization that oversees the use of the UMF trademark and honey quality testing. They also fund scientific research and continue to add to the body of knowledge around Manuka honey.

UMFHA keeps an updated list of members that produce honey which is graded according to the strict UMF quality standards.

UMF measures levels of MGO and DHA in Manuka honey to determine its NPA which is arguably the most reliable method. UMF also tests for the presence of leptosperin, a natural compound unique to Manuka, to assure purity of the honey. According to the UMFHA, 100mg/kg of leptosperin is enough to guarantee that the honey is genuine Manuka.

The numbers used by UMF to reflect the grade of the honey typically ranges from 5+ to 20+. You can find UMF Manuka honey of 30+ or higher but these are rare. The number reflects the antibiotic strength of the honey relative to the antibiotic strength of phenol.

Phenol is a common antiseptic and is often used in research as a benchmark to compare the relative strength of other antibiotic substances (like Manuka honey). A score of 5+ means the antibiotic strength of the Manuka is of equivalent strength to a mixture of 5% phenol and 95% water.  A score of 20+ means honey is as antibacterial as a 20% phenol / 80% water mixture.

It should be noted that anything less than a 10+ UMF Manuka honey is not considered to have significant antibacterial activity. So, go for honey that has at least a 10+ rating.

Bottom Line

UMF Manuka honey is some of the most trusted Manuka honey around, and for good reason. It ensures the honey is genuine Manuka and gives you a grade that accurately reflects the non-peroxide antibacterial potency of the honey.

KFactor Manuka Honey

KFactor is a grading system created and used exclusively by Wedderspoon. The current KFactor grading process is based on measuring the amount of pollen in the honey to determine purity.

KFactor does not measure the antibacterial strength of the Manuka honey.

Their website states that, in the future, they intend to measure MGO levels (among other things) as part of the KFactor grading system. This means they currently provide no insight into the NPA in their honey.

There are three different grades for KFactor manuka honey:

  • KFactor 12
  • KFactor 16
  • KFactor 22

While these numbers may look similar to other grading systems, they actually refer to the percentage of pollen in the honey that is Manuka pollen. Confusingly, KFactor 12 corresponds to 65% of the pollen being Manuka pollen, while KFactor 16 and 22 represent 75% and 90%, respectively. Why not just say 75% Manuka pollen on the label?

Wedderspoon doesn’t offer any explanations on their website as to why the numbers 12, 16, and 22 were chosen. It leads one to wonder whether the numbers were chosen intentionally to mislead consumers as they resemble the numbers used in other, more meaningful grading systems.

Set aside the seemingly arbitrary numbers for the KFactor grading system for a minute and consider this.

There are known issues with using pollen counts to identify Manuka honey. The issue being that Manuka produces identical pollen to other related species (like the Kanuka tree). This means KFactor honey could be Manuka honey as easily as it could be Kanuka honey. And, while it may taste like Manuka, Kanuka honey does not have the same NPA that Manuka honey does.

Bottom line

Not only does KFactor fail to measure the therapeutic quality of honey but it’s method of measuring ‘purity’ might leave you with a product that isn’t even genuine Manuka honey.

Avoid relying on the KFactor grading system if you’re looking for quality Manuka honey.

MGO Manuka Honey

MGO is probably the most straightforward grading system. In fact, it’s not as much a grading system so much as just stating how much methylglyoxal is in the honey.

This is a pretty reasonable approach since the amount of methylglyoxal is the primary factor that reflects Manuka’s antibacterial strength.

The MGO quality score ranges from as low as 30+ to over 800+, meaning that a honey rated MGO 550+ would have at least 550mg of MGO in one kilogram of honey.

One of the good things about using MGO levels as a grading system is that it’s straightforward. It’s relatively easy for any company to get their honey tested and put the results on their label.

The downside of this is that there is no third party oversight that ensures the MGO number on the label matches the MGO levels of the honey in the jar. It’s up to the company to test their own honey and put the results on the label.

One thing to note is that the presence of methylglyoxal in honey doesn’t necessarily guarantee that it’s genuine Manuka honey.

Many different kinds of honey have low levels of methylglyoxal that don’t provide any antibacterial benefit. If you’re buying lower grade honey (less than MGO 100) there’s no guarantee that the honey is primarily Manuka honey.

This ends up being a less important for higher grades above MGO 100+ as the honey likely wouldn’t have such high levels of MGO if it wasn’t pure Manuka honey.

Bottom Line

Using MGO as a grading system is a reliable way to assess the therapeutic strength of the honey. Just make sure you get it from a company you trust.

MGS Manuka Honey

The Molan Gold Standard (MGS) is a quality trademarked and grading system created by Dr. Peter Molan.

Dr. Molan is the scientist who originally discovered the non-peroxide antibacterial activity of Manuka honey. He was considered the leading authority on medical research on Manuka honey in the world until his death in 2015.

The MGS system runs independent audits at various stages of honey production to ensure that it’s quality standards are upheld by honey producers.

Like the UMF Manuka honey rating, MGS measures the levels of MGO and DHA in the honey and assigns a grade between 5+ and 30+. This number correlates to the equivalent phenol strength of the honey’s antibacterial activity.

MGS doesn’t test specifically for the purity of the Manuka honey by looking for Leptosperin. Rather, the MGS standard will not provide a grade for honey that has MGO levels of less than 100mg/kg.

Requiring a minimum MGO content of 100mg/kg ensures that the honey is genuine Manuka honey as only Manuka honey has MGO content that reaches these levels.

Bottom Line

The MGS grading system is a trustworthy grading system that was created by the leading authority on Manuka honey. It’s independent tests and auditing ensure their honey’s purity and quality.

Active / Bio Active / Total Activity

Other companies use grading systems like ‘Active’, ‘Bio Active’ or ‘Total Activity’. These grading systems refer to both the peroxide and non-peroxide activity of the honey. This is very misleading as the hydrogen peroxide antibacterial activity degrades very quickly when exposed to fluids, heat, and sunlight.

Often times when these brands of honey are tested they contain very low levels of methylglyoxal and don’t show any non-peroxide antibacterial activity.

Bottom Line

Avoid companies that use labels like ‘Active’ or ‘Bio Active’. These labels are very misleading and are unlikely to offer any of the antibacterial benefits manuka honey is known for.

Final Words

UMF Manuka Honey and MGS are your best bets

These grading systems accurately reflect the non-peroxide antibacterial activity that Manuka honey is so highly prized for. Third party independent testing and verification ensures the quality of the honey that’s in the bottle will match or exceed what’s on the label.

MGO is a solid second choice

If you can’t find a UMF or MGS Manuka honey, a honey that displays the amount of MGO on the label is a great second choice. The only thing to keep in mind is that there is no third party testing and verification of these claims so make sure it’s from a company you trust.

Avoid KFactor and Bio Active Manuka honey

If all you care about is the taste of Manuka honey (and it tastes wonderful) then these grading systems will serve you just fine. However, most people are interested in Manuka honey’s unique antibacterial characteristics. If you’re in the later group, steer clear of brands that use these confusing and borderline misleading grading systems.