Understanding MGO Grades in Australian Mānuka Honey
MGO is the most common way Australian Mānuka honey is graded, but the number is often misread. A plain explanation of what it measures, how it forms, and what it does and does not tell a wholesale buyer.
If you buy or sell Mānuka honey, the first thing on almost every specification sheet is a grade — most often an MGO number. It drives price and positioning, yet it is one of the most misunderstood figures in the category.
What MGO actually measures
MGO stands for methylglyoxal, a compound naturally present in Mānuka honey. A grade such as MGO 400 means the honey was measured to contain at least 400 milligrams of methylglyoxal per kilogram (mg/kg). It is a concentration of one compound — not a score, a rating out of a maximum, or a measure of any outcome.
How MGO forms
Methylglyoxal does not come directly from the bee. It forms from dihydroxyacetone (DHA), a compound found in the nectar of Leptospermum plants. Over time, and influenced by storage temperature, DHA converts into methylglyoxal — which is why two honeys from the same source can carry different MGO figures depending on age and handling.
MGO, NPA and other grading systems
- MGO — the measured methylglyoxal concentration in mg/kg. A direct chemical measurement.
- NPA (Non-Peroxide Activity) — an antibacterial-activity measure reported in laboratory terms, distinct from the peroxide activity common to most honeys.
- Other proprietary marks — some sit on top of these measurements. They are not a substitute for seeing the underlying figure and the report behind it.
The Australian context
Australian Mānuka honey is produced from native Leptospermum species. For an export buyer, the relevant questions are whether the honey is genuinely from these sources, whether the grade is measured on the batch being shipped, and whether origin can be evidenced.
How to read a grade on a spec sheet
- Is the MGO figure stated in mg/kg and tied to a specific batch?
- Is there an independent test result you can see, rather than only a tier label?
- Is the same grade you were quoted the grade on the batch documentation?
- Are claims limited to what was tested, without drifting into health or therapeutic language?
Treat an MGO grade as a measured concentration of one compound, verified per batch — not as a quality score or an outcome. If a supplier can show the number on the batch report and keep claims to what was tested, the grade is doing its job.
Selveh intends to present analytical measures plainly — MGO as methylglyoxal concentration in mg/kg and, where applicable, NPA as non-peroxide activity — without associating them with therapeutic or medical outcomes.