Manuka Honey Ratings Explained: What You Need To Know


8 minutes

Essential Takeaways

There are a few different manuka honey ratings. Some of them, like UMF™, MGS, and K-Factor™ are grading systems that test various chemical markers in the honey.

Others simply indicate the content of a single chemical marker, like MGO and NPA.

But almost all of these manuka honey numbers at their core are based on the measure of MGO (or methylglyoxal) in the honey. That’s because MGO is what makes manuka honey unique and sought-after.

If you’re after the top-quality monofloral manuka honey exported from New Zealand, the manuka honey grade to look out for is UMF™. This is the system with the strictest requirements and most comprehensive process.

Are you interested in buying manuka honey but confused by all the acronyms?


What do all these manuka honey ratings mean, and is one more trustworthy than the others?

The answer is: Yes. These manuka honey numbers are all useful for different things, but not all of them are regulated to the same strict standards.

If you’re after the top quality stuff, then you need to know the difference.

That’s what this guide is for: shedding light on the various manuka honey gradings, what they mean, and how to choose the right one for you.

In this guide to manuka honey ratings:

  • Understanding manuka honey numbers

  • Manuka honey grading systems

  • Manuka honey chemical markers

  • Why do these manuka honey grades exist?

  • What’s the best manuka honey rating?

  • How to choose the right manuka honey grade for you

  • Where to buy certified, authentic manuka honey

Understanding Authentic Manuka Honey Numbers

There are a few different manuka honey numbers that you might come across when searching for authentic manuka honey from New Zealand.

Some of these numbers are gradings, and others indicate chemical markers in the honey.

They exist to protect the integrity of genuine honey producers and for consumers to verify what’s in the jar they’re buying. Some are better for this than others (but more on that later).

Here’s an overview of the key manuka honey ratings:

Grading Systems


What it verifies

100% pure monofloral manuka honey from NZ

Manuka honey from NZ

What the numbers indicate

Higher grades indicate more MGO

Higher grades indicate more MGO

In a nutshell

Considered the strictest and most thorough testing for manuka honey

Relatively thorough test that verifies genuine manuka honey

Chemical Markers


What it verifies

Methylglyoxal content

Non-peroxide activity

What the numbers indicate

The MGO content in mg/kgText

The NPA level as it correlates to MGO content

In a nutshell

A measure only of the MGO content and not of authenticity. Look for UMF™ label for extra assurance.

Used more in the UK than elsewhere

Other than K-Factor™ ratings, all the manuka honey numbers above directly relate to its MGO content and resulting antibacterial activity.

In fact, you might notice in the next table that the UMF™ grades match the NPA levels.

Here’s a comparison of how UMF™ grades relate to MGO ratings and NPA:

UMF™ MGO (mg/kg) NPA















And how MGS grades relate to MGO content:

MGS MGO (mg/kg)












≥ 100

≥ 200

≥ 300

≥ 400

≥ 500

≥ 600

≥ 700

≥ 800

≥ 900

≥ 1050

≥ 1100


So what’s with all the acronyms?

Let’s dive a little deeper.


Genuine Manuka Honey Grading Systems: UMF™, MGS, and K-Factor™

There are three key manuka honey grading systems.

The most common and probably most famous is the UMF™ grading system. It’s considered to be the best, most rigorous testing available for manuka honey.

But there are two slightly less well-known systems that you might come across too.

Let’s explore them.

UMF™ (Unique Manuka Factor)

UMF™ is an independent manuka honey grading system developed by the UMFHA (Unique Manuka Factor Honey Association).

It tests for four chemical markers in a jar of manuka honey:

  • MGO for potency. Methylglyoxal is the key antibacterial agent in manuka honey so it forms the base of most manuka honey gradings - not just UMF™.

  • Leptosperin for authenticity. This compound is only found in mānuka flowers and has been linked to anti-inflammatory benefits¹.

  • HMF for freshness. Hydroxymethylfurfural (HMF) is a compound that indicates whether honey has been overheated or stored for too long (thereby compromising its beneficial properties).

  • DHA for shelf life. Dihydroxyacetone (DHA) slowly converts to MGO naturally. So the more DHA present in a batch of honey, the longer the beneficial properties will last. There must be at least 70mg/kg of DHA for a batch to be awarded a UMF™ grade.

If you buy manuka honey with a UMF™ grade, you can be sure that the honey has passed some of the strictest, most comprehensive tests for quality, authenticity, and freshness.

Read more: Honey with UMF™: Clearing up the confusion.

MGS (Molan Gold Standard)

The Molan Gold Standard system was developed by and named after Dr. Peter Molan, the scientist that first studied the unique properties and potential health benefits of manuka honey.

Like UMF™, MGS is an independent manuka honey grading system.

It mainly focuses on the MGO (methylglyoxal) content of the honey, and certifies quantities between 100mg/kg and 1100mg/kg.

Whilst it verifies that a manuka honey batch contains MGO, comes from the mānuka plant and was packaged in New Zealand, it is not considered as thorough and rigorous as the UMF™ testing system.


K-Factor™ is another manuka honey rating system developed and used by a single honey producer.

This system verifies the pollen count of the honey, that it’s non-GMO, that it’s raw or pasteurised, glyphosate free and traceable to NZ hives.

But it doesn’t measure the antibacterial components of the honey, its freshness, or whether it’s truly a monofloral manuka honey.

Kānuka pollen and other species related to mānuka can look deceptively similar in chemical tests, but they don’t have the same beneficial compounds.

This system doesn’t guarantee that you’re buying 100% pure, monofloral manuka honey in the same way that UMF™ does.

Manuka Honey Chemical Markers: MGO and NPA

MGO is the most common chemical marker number that you’ll find on manuka honey jars. And that’s because it’s the naturally occurring compound that makes manuka honey unique².

But you might also find another number on the jars: NPA.

Here’s the difference.

MGO (Methylglyoxal)

MGO stands for methylglyoxal, a naturally occurring compound found in manuka honey.

Manuka honey has unique antibacterial properties and associated health benefits that are not found in regular honey to the same extent, and this is attributed to its methylglyoxal content³.

The MGO rating on a jar of manuka honey indicates how many milligrams of methylglyoxal there are per killogram of that honey batch.

For example, our UMF™ 28+ | MGO 1450+ manuka honey contains at least 1450mg of MGO per kilogram of manuka honey.

Manuka honey jars that only display an MGO rating haven’t necessarily been rigorously and independently tested to the same standard as jars that also display UMF™ grades.

Read more: What does MGO mean on manuka honey?

NPA (Non-Peroxide Activity)

All honeys contain hydrogen peroxide⁴, a naturally-occurring chemical compound⁵. This peroxide has been associated with the antibacterial effects of honey.

But studies show that the particularly high levels of antibacterial activity found in manuka honey are not linked to hydrogen peroxide.

Instead, it’s the non-peroxide activity, or NPA, that sets manuka honey apart⁶.

Since MGO (methylglyoxal) is the key antibacterial agent in manuka honey, the calculation of NPA is based on MGO rating and content. In fact, you might notice that the UMF™ grades perfectly align with the NPA levels in our comparison table.

As a label alongside UMF™ or MGO, it’s a little surplus to requirements, and is more commonly used in the UK than elsewhere.


Why Do These Manuka Honey Grades Exist?

Due to its age-old reputation as a health and wellness hero, honey has become one of the most faked foods on earth.

In fact, as much as 70% of the honey on US supermarket shelves could be fake or contaminated with other ingredients⁷.

With its reputation for superior health benefits and a price tag to match, authentic manuka honey from New Zealand is particularly vulnerable to fraudulent claims.

In order to protect consumers and the integrity of the authentic manuka honey produced, official regulatory bodies and certifications have been established.

For a jar of honey to display a UMF™ grade (like ours), it needs to have passed robust testing by the independent UMFHA.

Thanks to this rigorous process, buyers can trust that they’re getting a genuine product. And the responsible suppliers are also protected.

What’s The Best Manuka Honey Rating?

The best manuka honey rating to pay attention to depends on what you’re looking for.

If you want top-quality, authentic monofloral manuka honey from New Zealand, then look for a UMF™ grade.

No other manuka honey rating will give you the same level of quality assurance.

If you’re happy with a honey tested only for its antibacterial properties, without evidence of its floral composition, country of origin, or freshness, then looking for an MGO number or NPA number does the job.

How To Choose The Right Manuka Honey Grade For You

Do you know which manuka honey rating you trust, but you’re unsure of the grade to go for?

That’s understandable, there’s a lot of them!

(We’ll refer to UMF™ grades here since that’s how we rate our manuka honey and it’s the most credible system. But if you’re thinking about using another rating, refer to our comparison tables).

What’s the difference between UMF™ 5+ and UMF™ 20+ in a practical sense?

Remember that higher UMF™ grades have higher concentrations of antibacterial activity. So the spectrum really evolves from general daily wellness boosts up to medical application for serious conditions.

Here’s how we recommend using different UMF™ grades:

Grades Use

A general health and wellness boost that the whole family can take daily.

Daily wellness with a little extra kick. This is also great for skincare.

The premium grades. These are good for medical uses e.g. to promote wound healing, scars, sore throats, and acne.

Top of the line, ultra premium grades. These are ideal for more serious medical complaints* as well as for more powerful wellness boosts.

For more detail about buying genuine manuka honey, choosing the right grade for you, and for ideas on how to incorporate manuka honey into your wellness routine, check out our dedicated guide: How much UMF™ is enough?

Or take our quiz.

*NB: Remember to always check with your doctor before using anything for medical conditions, even all-natural products like honey.

Shop Independently-Certified Raw Manuka Honey from NZ

Our raw UMF™ grade manuka honey is tested by the UMFHA and two independent labs for the greatest quality assurance.

Our real manuka honey is also:

  • Non-GMO certified

  • Glyphosate free

  • Fernmark licensed

  • Halal certified

  • Kosher certified

  • Made with sustainable packaging

We are committed to providing our customers the greatest transparency in where their raw honey comes from and exactly what’s in the jar.

We only deal with real.

Find out more about our accreditations here.

Shop the manuka honey range.


Your wellness journey starts with a spoonful a day.


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