MGO stands for Methylglyoxal. It is the compound found in Manuka honey and is responsible for the activity in the honey. Although not a technical grading system, Methylglyoxal is very valid and is measured in milligrams per kilogram of Manuka honey. It can be measured alongside UMF, which is the grading system we use. We find this to be helpful for our customers and helps them understand the different grades and what they mean. For example a Manuka Honey UMF 15+ is equivalent to MGO 514+.