If you have ever stood in front of a shelf of Manuka honey wondering why one jar costs $34.50 and another costs $241.50, the answer is almost always the number on the front: MGO.
This guide explains what that number measures, how it gets there, how it compares to the UMF system you will see on New Zealand jars, and which grade actually suits what you want to use it for.
What MGO actually measures
MGO stands for methylglyoxal. It is a naturally occurring compound found in authentic Manuka honey, and the number on the jar is a direct measurement of how much of it is present, expressed in milligrams per kilogram (mg/kg, sometimes written as ppm).
So MGO 500+ means the honey was independently tested and contained at least 500 mg of methylglyoxal per kilogram of honey.
The important word there is measured. MGO is quantified directly using high-performance liquid chromatography (HPLC), a standard analytical laboratory method. This is why MGO has largely replaced the older non-peroxide activity (NPA) rating, which relied on an agar plate assay method that the Australian Manuka Honey Association describes as over 100 years old and prone to error.
Where MGO comes from: the DHA story
Manuka honey does not start out high in MGO. It starts out high in DHA (dihydroxyacetone), a compound that occurs naturally in the nectar of Leptospermum flowers and is not found in other floral honey types.
Over time, DHA slowly converts into MGO inside the honey. That conversion is not instant — it takes roughly 12 to 24 months. This is why patience matters in Manuka production, and why two jars from the same hive can test very differently depending on when they were packed and how they were stored.
It also explains why DHA is tested alongside MGO. As the AMHA puts it, the MGO level indicates the honey's potency, while the DHA level demonstrates that the potency was produced naturally by bees working active Manuka plants — rather than arriving by some other route.
The Australian standard: what "Manuka" legally requires
Australia has a defined standard, set by the Australian Manuka Honey Association through a Scientific Advisory Committee of researchers including Dr Peter Brooks, Dr Craig Davis, Dr Shona Blair and Dr Nural Cokcetin.
To carry the AMHA Mark of Authenticity, honey must be produced in Australia, tested by an independent approved laboratory, and meet minimum MGO and DHA levels when packed:
| AMHA mark | Minimum MGO | Minimum DHA |
|---|---|---|
| AMHA Authorised | 30 mg/kg | 60 mg/kg |
| AMHA Authentic | 85 mg/kg | 170 mg/kg |
Source: AMHA Criteria for Defining Australian Manuka Honey.
The honey must also be verifiably produced from Leptospermum nectar, assessed through flow diaries, colour, flavour, chemical marker analysis and pollen analysis. A further marker, leptosperin, is present in all Australian Manuka honeys and is regarded by its discoverer, Professor Yoji Kato, as a signature of Manuka authenticity.
The practical takeaway: any genuine Australian Manuka sits above MGO 30, and anything labelled "Manuka" without a tested MGO figure should raise a question.
MGO to UMF: the conversion table
New Zealand jars typically carry a UMF rating instead of MGO. UMF and MGO are not different scales for different things — UMF grades correlate to specific MGO concentrations, so you can convert between them.
These are the pairings from the UMF Honey Association's published conversion chart:
| UMF | Equivalent MGO (mg/kg) |
|---|---|
| UMF 5+ | MGO 83+ |
| UMF 8+ | MGO 182+ |
| UMF 10+ | MGO 263+ |
| UMF 12+ | MGO 354+ |
| UMF 15+ | MGO 514+ |
| UMF 18+ | MGO 696+ |
| UMF 20+ | MGO 829+ |
| UMF 22+ | MGO 971+ |
| UMF 25+ | MGO 1200+ |
Source: UMF Honey Association conversion chart, as published in this MGO to UMF comparison.
Two things worth noticing. First, a UMF 20+ jar is roughly MGO 829+ — so a UMF 20+ and an MGO 830 jar are broadly comparable, despite the very different-looking numbers. Second, the scale is steep at the top: moving from UMF 5+ to UMF 10+ roughly triples the MGO, and the increments keep widening from there.
Why high grades cost so much more
MGO is not a dial a producer can turn. It depends on which Leptospermum species the bees worked, the nectar's DHA concentration, seasonal conditions, and how long and how carefully the honey was matured.
High-MGO flows are genuinely uncommon. AgriFutures-funded research found that storage temperature and maturation time both affect whether a honey reaches its full potential — meaning a high grade reflects both a rare harvest and disciplined handling afterwards. The rarity, not the marketing, is what sits behind the price curve.
Choosing a grade: the Goldland Co range
Our range runs the full ladder, which makes the comparison straightforward:
| Grade | Size | Character | Price |
|---|---|---|---|
| MGO 100+ | 250g | Entry active — gentle and approachable, an everyday Manuka | $34.50 |
| MGO 250+ | 250g | Daily active — noticeably richer, still generous for regular use | $52.50 |
| MGO 500+ | 250g | Everyday active — the grade most customers choose first | $76.50 |
| MGO 700+ | 250g | High active — concentrated and distinctly intense | $100.50 |
| MGO 900+ | 250g | Ultra active — our highest 250g grade, popular for gifting | $130.50 |
| MGO 1780+ | 150g | Our house grade — cold-extracted, limited numbers | $241.50 |
A practical way to decide
- New to Manuka, or want it on toast and in tea? Start at MGO 100+ or MGO 250+. You get the genuine article at a price that lets you use it freely.
- Want a single jar that does everything? MGO 500+ is the balance point, and the reason it is our most-chosen grade.
- Already know you want the concentrated end? MGO 700+ or MGO 900+, taken by the spoon rather than spread by the knife.
- Buying a gift, or want the rarest thing we make? MGO 900+ presents beautifully at 250g. MGO 1780+ is the one we are quietly proudest of.
One honest note on flavour: higher MGO tastes stronger. It is more intense, more mineral, less like the honey most people grew up with. If you are buying for someone who has never tried Manuka, a mid grade is often the kinder gift.
Reading a label properly
Four things to check on any jar:
- A specific tested MGO number — not "active", not "bioactive", not "premium" on its own.
- Country of origin. Australian Manuka comes from Australian Leptospermum. Blended or repacked product should say so.
- Independent laboratory testing. The number should trace back to an approved lab, not an in-house estimate.
- Monofloral or multifloral. The AMHA defines pure monofloral Manuka as having at least 50% of nectar from a single floral source; multifloral Manuka blends include nectar from other sources.
You can browse the full Goldland Co range by grade here.
This article explains how Manuka honey is graded and tested. It is general information about grading systems, not health or medical advice, and nothing here is intended as a therapeutic claim. If you are considering Manuka honey in relation to a health condition, speak with a qualified healthcare professional.
