Manuka Grading Systems

Manuka honey has different potencies. It is important to understand what HPA, NPA, UMF & MGO printed on the label actually mean and how they relate to the honey’s antibacterial strength.

What is HPA?

Hydrogen Peroxide Activity (HPA) occurs when bees convert nectar into honey. It has antibacterial properties, but is easily destroyed by heat and light. Most fresh honeys have some level of HPA, but it rarely survives the journey from hive to home which is why few commercial honeys are capable of healing by the time they make it to the pantry shelf. That’s where Manuka is different.

Even when its HPA is destroyed, tests show Manuka honey still has powerful antibacterial properties. And the reason for this is the honey’s NPA.


NPA (non-peroxide activity) or UMF® (unique manuka factor) ratings are used to describe the unique antimicrobial activity of Manuka honey. The NPA and UMF® ratings are generated by the same type of test, but ‘Unique Manuka Factor’ (UMF®) is a trademark registered by the UMF Honey Association of New Zealand. UMF® is only available for licensed use by UMF Honey Association of New Zealand members in relation to honey originating in New Zealand. NPA and UMF® are the equivalent of each other when tested by an appropriate laboratory.


MGO occurs naturally in authentic Manuka honey, and this is the component responsible for much of its non-peroxide activity (NPA). The amount of MGO in Manuka honey can be measured directly, using specialist chemistry equipment, and it is expressed as parts per million (ppm) or mg/kg.

MGO is the centrepiece of our Australian Manuka honey rating system.

This is in line with changing international standards and labelling requirements.


The approximate relationship between MGO concentration and the NPA/UMF® of Manuka honey is: