MGO (methylglyoxal) is the compound Manuka honey is graded on when a jar skips UMF certification and lists a raw number instead, common tiers run 100+ to 829+. MGO 263+ tracks close to UMF 10+, though the two systems test differently. Below, a retail-verified conversion table lines them up side by side.
What Is MGO in Manuka Honey?
MGO is a direct measurement, a specific compound tested in milligrams per kilogram, not a composite standard the way UMF is. It forms from DHA, a precursor present in fresh Manuka nectar, which converts into MGO gradually as honey matures in storage over its first year or so on the shelf. That’s why a jar’s actual MGO level can still climb slightly after the number on the label was set.
How MGO Is Measured (HPLC Testing)
MGO is tested using HPLC (high-performance liquid chromatography). The honey sample is derivatized with a reagent that converts MGO into a stable, measurable compound, then run through the HPLC system for a precise reading. The same run typically measures DHA and HMF alongside MGO, since labs are already set up to catch all three markers together.
HMF matters here because it complicates reading an MGO number in isolation. A high HMF reading signals heat or storage damage, and a damaged jar’s MGO reading reflects whatever’s left after that damage, not necessarily what the honey started with.
Common MGO Numbers Explained, 100+ to 829+
MGO 100+
Sits just above the MGO 83+ floor that corresponds to UMF 5+, but below UMF 10+’s MGO 263+ threshold. There’s no clean UMF equivalent for this number, it’s a step up from the lowest UMF-certified tier without reaching the next one.
Worth it for: a modest, affordable step above entry-level, still fine for everyday use.
MGO 263+
The common mid-tier, and it tracks closely with UMF 10+. This is the number most buyers researching MGO-graded jars land on for daily use.
Worth it for: the practical floor if graded potency is the actual reason you’re buying Manuka.
MGO 400+
Sits between UMF 10+’s MGO 263+ and UMF 15+’s MGO 514+, another number without a clean UMF equivalent.
Worth it for: splitting the difference if you want more than the common mid-tier without the price jump to the next full UMF-equivalent step.
MGO 514+
Tracks closely with UMF 15+, roughly double MGO 263+.
Worth it for: undiluted use, tea or straight off a spoon, where the higher concentration actually matters.
MGO 829+
Tracks closely with UMF 20+, a meaningfully rarer harvest requirement and priced accordingly.
Worth it for: wanting real margin, or using it concentrated rather than diluted.
MGO to UMF Conversion Table
| MGO | Approximate UMF Equivalent |
|---|---|
| 83+ | 5+ |
| 100+ | Between 5+ and 10+, no exact equivalent |
| 263+ | 10+ |
| 400+ | Between 10+ and 15+, no exact equivalent |
| 514+ | 15+ |
| 829+ | 20+ |
These figures are kept in sync with the full grading system comparison, the site’s single source for every conversion value. If that table is ever updated, this one updates with it.
Why MGO and UMF Aren’t Always Interchangeable
The conversion above is “roughly equivalent,” not “the same test,” and the gap is leptosperin. UMF requires a verified leptosperin floor to confirm genuine Manuka origin. A raw MGO number doesn’t check for that at all.
KFactor, used on Wedderspoon’s labels, doesn’t belong on this table. It measures pollen count, not methylglyoxal, so there’s no MGO or UMF equivalent to convert it to. NPA (non-peroxide activity) is an older term describing roughly the same underlying property as UMF and MGO together, numerically close to UMF on jars that still use it.
Comvita is a useful contrast point here: it sells UMF-graded honey, not MGO-only, which is part of why you won’t find a Comvita jar on this tier list, its labeling uses the composite UMF standard instead of a raw MGO number.
How to Verify an MGO Claim Is Real
Most MGO-only brands aren’t UMFHA-licensed, that’s a UMF-specific certification, so verifying an MGO claim looks a little different:
- Look for a batch certificate or lab report, not a UMFHA license number. An MGO-only brand won’t have one, since that license is specific to UMF certification.
- Check for MPI export marks. MPI (New Zealand’s Ministry for Primary Industries) certifies origin and export regardless of which grading system a brand uses.
- Match the batch number on the jar to the batch certificate, the same way you would for a UMF-graded jar. A certificate for a different batch doesn’t confirm anything about the jar in your hand.
- Treat a bare MGO number with no batch certificate at all as a red flag. A real claim should be traceable to an actual lab result, not just a number printed on a label with nothing behind it.
FAQ
Is a higher MGO number always better?
Not for every use. A higher number means more methylglyoxal, but for coffee, tea, or general use where the honey gets diluted, the common mid-tier numbers usually deliver enough without paying for potency that gets diluted away regardless.
Can I convert KFactor to MGO?
No. KFactor measures pollen count, not methylglyoxal, so there’s no conversion between the two. A KFactor number on a jar doesn’t tell you anything about its MGO level.
Does Comvita use MGO or UMF?
Comvita grades its honey under UMF, the composite certification, rather than selling jars under a standalone MGO number the way some other brands do.
Why doesn’t an MGO-graded brand have a UMFHA license number?
Because UMFHA licensing is specific to UMF certification. A brand grading by MGO alone is testing and stating that one compound directly, without going through UMFHA’s separate certification process, which is why the two verification paths look different.