NPA, IAA, K-Factor, MG, "Active": decoding every Manuka label that isn't UMF

Buy Manuka in three different countries and you will come home with three different vocabularies. One jar says UMF 20+. Another says NPA 10+. A French jar says IAA 20+. An American one says K-Factor 16. Somewhere there is a jar that just says "Active".

They are not all the same kind of claim, and a few of them are not really claims at all. Here is the whole vocabulary, sorted into what it is worth.

A note before we start. In the European Union, honey is a food. Food labels may not carry health claims unless those claims are on the authorised EU list, and there are none for Manuka. So everything below describes measurement and grading systems — what a number counts and who verifies it. Nothing here is a statement about what honey does for you.

The systems that are actually verified

UMF — Unique Manuka Factor. A certification programme run by the UMF Honey Association in New Zealand. A licensed producer's honey is tested for four markers: MGO, DHA (the precursor that converts into MGO over time), leptosperin (a natural compound found in Manuka nectar that is extremely difficult to imitate, so it is the authenticity check) and HMF (which rises with age and heat, so it is the freshness and handling check). A genuine UMF jar carries a licence number you can look up. This is the most demanding of the systems, because it tests identity and condition, not only strength.

MGO — methylglyoxal, sometimes printed as MG. A straightforward concentration in milligrams per kilogram. MGO 550 means at least 550 mg/kg. It is honest and easy to compare, but on its own it says nothing about authenticity or freshness. MG and MGO are the same measurement, just abbreviated differently.

NPA — Non-Peroxide Activity. An older laboratory scale, expressed in "phenol equivalents". Its numbers line up with UMF: NPA 10+ occupies the same position as UMF 10+, and NPA 5+ the same as UMF 5+. If you see a jar labelled "MGO 83+ / NPA 5+", it is telling you the same thing twice.

IAA. The label you will most often meet on French-language packaging. It works the same way as NPA and uses the same numbers, so IAA 20+ sits where UMF 20+ and NPA 20+ sit. If your jar says IAA and you want to compare it with a UMF jar, you can read the numbers directly against each other.

MGS — Molan Gold Standard. A separate New Zealand certification programme, named after the researcher who first studied Manuka. Less common than UMF but a real certification with real testing behind it.

The layer underneath all of them: New Zealand government law

This one is not a marketing scale at all, and it matters more than most shoppers realise.

Since 2018, every batch of honey exported from New Zealand as Manuka must pass the Ministry for Primary Industries scientific definition: a test of four chemical markers plus a DNA marker from Manuka pollen. Only honey that passes may be labelled monofloral Manuka (predominantly from Manuka nectar) or multifloral Manuka (a genuine but more mixed harvest).

So "monofloral Manuka honey, product of New Zealand" is not a slogan. It is a legal classification that a government laboratory has signed off. Any grading number sits on top of it.

The labels that mean less than they look

"Active", "Bio Active", "Active 12+". These words are not owned by anyone and are not certified by anyone. Sometimes they sit alongside a real number; often they replace one.

TA — Total Activity. This sounds like more than NPA because it is a bigger number, and that is exactly the problem. Total Activity adds together the non-peroxide activity and the ordinary peroxide activity that virtually every honey in the world has. It inflates the figure without adding anything specific to Manuka, and the industry has largely moved away from it. A "TA 20+" is not comparable to a UMF 20+.

K-Factor. A brand-specific scale built around pollen count, freshness and purity — questions of what the honey is, not how concentrated its signature compound is. K-Factor 16 does not mean UMF 16 and does not convert to it.

A number with no scale named. "Manuka 300", "Manuka AA 300", "Manuka 24" — if the jar does not say which system the number belongs to, you cannot compare it to anything. Ask, or move on.

A number without a plus sign, or with "up to", is describing a ceiling rather than a guaranteed minimum.

The quick translation table

If you have an MGO number and want the UMF equivalent, our full MGO to UMF conversion table does the arithmetic for you.

Three checks that settle almost any jar

One: is a system named? UMF, MGO, NPA, IAA, MGS — a named system means a defined test. No named system means no test you can verify.

Two: is there a licence or batch number? UMF licensees print a licence number. Serious producers print a batch or lot code that ties the jar to a specific tested harvest.

Three: does it say monofloral or multifloral Manuka, product of New Zealand? That is the government layer, and it is the difference between Manuka honey and honey with the word Manuka on it.

The takeaway

Most of the alphabet on a Manuka shelf resolves to one of two things: a certified measurement (UMF, MGO/MG, NPA, IAA, MGS) or a word someone chose ("Active", "Bio Active", TA, an unexplained number). The first group can be compared with a table. The second group cannot be compared at all — which is usually the point of using it.

Learn the five real systems and the shelf stops being confusing.