What does the MGO and NPA ratings mean? Which one should I use?

For commercially competitive reasons there have been a number of symbols introduced into the market over recent years that are aimed to represent the strength of Manuka, such as UMF, NPA and MGO. While the NPA rating is the most widely understood rating, we have begun transitioning to the MGO rating, because the strength is easily measured analytically, and levels can be accurately quantified in milligrams per kilograms.

The highest rating indicated the higher antibacterial activity level in the honey. Below is a simple table to assist with understanding the different ratings.

Manuka Activity Rating Conversions