What is MGO in Manuka Honey: Ratings & the New Zealand Government's Science Definition

Every jar of Manuka Doctor honey is labelled with numbers which show the strength of its MGO content and confirm it is genuine Manuka Honey.

Want to know exactly what it all means? We asked the experts to explain what the numbers stand for and why they are on the label.

The large number on the front of every jar of Manuka Doctor honey is its MGO rating – which shows the strength of the honey’s antimicrobial activity.

MGO is short for methylglyoxal, the naturally-occurring chemical unique to honey made from nectar gathered from the Mānuka bush. Scientific tests have shown this chemical has antimicrobial properties and the more the honey contains, the greater its bug-fighting power [1].

The MGO scale starts around 30 and goes right up to 1300.

As a general rule, Manuka honey with an MGO rating between 30 and 100 is ideal for everyday wellness. While Manuka honey with an MGO rating of between 140 and 250 is better for a daily boost.

Manuka with an MGO rating between 340 and 540 is good for an extra wellness boost.

Anything between 640 MGO and 940 MGO is a maximum strength product best for when your body really needs support.

And occasionally we are able to harvest Manuka with a very high grade of 1000 MGO to 1300 MGO – which is best for intensive support.

Dr Young Mee Yoon, Chief Technical Officer at Manuka Doctor, explains: “The MGO rating is established through a scientific chemical analysis which looks at three different chemicals present in the honey. The results tell us the activity level of the honey.

“We test all our honey to establish its MGO level, first in New Zealand using our own highly technical in-house equipment and then again in an independent laboratory when it arrives in the UK, which means we can guarantee the MGO rating stated on the label is correct and true to label.”

You may have also seen the UMF® rating used on Manuka Honey. You can read more here about our MGO ratings and the corresponding UMF® rating.

Each jar of Manuka Doctor honey carries labels confirming the honey meets the strict definition of Manuka Honey set by the New Zealand Government and is “Tested Certified Manuka”.

This means each batch has been tested at an independent laboratory for five key markers which prove the honey was made from nectar gathered by bees from the Mānuka bush. The markers are made up of four naturally-occurring chemicals and one DNA marker from Manuka pollen.

Our jars also state the honey is either “monofloral” or “multifloral”. This tells you whether the honey is made predominantly from nectar from the Mānuka bush (monofloral) or from a combination of Manuka and other flowers (multifloral).

Independent testing establishes how much of each of the five markers are in each batch of honey – and these results are used to determine whether it is monofloral or multifloral Manuka Honey.

Typically, monofloral products contain higher levels of the natural chemicals associated with the Mānuka bush.

There are five key markers which identify whether Manuka Honey is monofloral or multifloral. The first four are chemical markers known as phenolic acids. Their full names are called 3-Phenyllactic acid, 2-Methoxyacetophenone, 2-Methoxybenzoic acid and 4-Hydroxypheyllactic acid – so you can see why we can’t fit them on our labels!

Instead, every Manuka Doctor jar displays the minimum levels it contains of each of the chemicals, referred to by their shortened names: 3-PLA, 2-MAP, 2-MBA and 4-HPLA.

For honey to be classed as “monofloral” it has to contain at least 400mg/kg of 3-PLA and 5mg/kg of 2-MAP, as well as at least 1mg/kg of the other two chemicals. “Multifloral” Manuka Honey contains between 20 and 400 mg/kg of 3-PLA and at least 1mg/kg of the other three chemicals.

All honey which is exported from New Zealand as “Manuka” must also contain a DNA marker from Manuka pollen, which confirms it has come from the bush. This is why every Manuka Doctor jar also states: “DNA < Cq 36” – this is a scientific way of saying the presence of Manuka DNA has been confirmed by independent laboratory testing.

All Manuka Doctor honey is independently tested at third party labs to ensure it meets the Strict New Zealand MPI Standard for Genuine Manuka.

Jonno Hill is CEO of one the approved labs, Hill Laboratories. He says:

“We test for the four chemical markers using a Government-recommended chemical analysis technique called LC-MS (liquid chromatography–mass spectrometry). It’s a highly analytical technique which is expensive but very reliable and wonderfully precise and scientific, so it is free from interferences which could give inaccurate results."

“For the DNA testing we use an analytical technique called quantitative PCR, which is also Government-recommended. We use it for a range of services in the business and it’s a technology which is very well established and there a high degree of confidence in its accuracy.”

At Manuka Doctor we also use FERA labs to undertake batch testing. In fact you can even see the testing certificates for the batch of honey you buy.

Dr Mark Harrison from FERA leads the Authenticity Team. He says:

“If you’re buying Manuka that’s been tested, you might see one of these certificates. It shows you that the honey has been checked to make sure it contains the right levels of MGO and associated natural compounds.”

“The certificate is important because it proves that what you think you’re buying, is actually true. And proves the authenticity of Manuka Doctor honey.”