What does UMF™ mean?
UMF™ stands for 'Unique Manuka Factor', a trusted standard of measure established by the Unique Manuka Factor Honey Association (UMFHA). It was set up to give consumers confidence that what they are buying is genuine, and it is one of the strictest honey accreditation programmes in the world.
The UMF™ grading system measures natural markers found in Manuka honey and assures quality, purity, and authenticity. This system is also compliant with New Zealand's Ministry for Primary Industries' labelling guidelines for Manuka honey. To be certified with a UMF™ grade, a batch of honey must be independently tested by UMFHA.
Why does this matter chemically? Laboratory research first identified methylglyoxal (MGO) as the compound primarily responsible for the distinctive non-peroxide antibacterial activity that sets New Zealand Manuka honey apart from other honeys, with concentrations found at levels up to roughly 100 times higher than in non-Manuka honey. It is worth noting that this describes a chemical mechanism identified through laboratory testing, not a guaranteed clinical outcome — it explains why Manuka honey is treated differently, rather than making a treatment promise.
Separately, analytical chemists have explored other ways to verify Manuka authenticity. Research using proton NMR spectroscopy combined with statistical modelling suggests that the three key Manuka marker compounds — methylglyoxal, dihydroxyacetone (DHA), and leptosperin — can be measured together in a single test to estimate how much genuine Manuka honey is present in a sample. This is laboratory analytical evidence supporting the broader scientific basis for authenticity testing as a field; it is a separate line of research from, and not a validation of, any single grading brand such as UMF™.
For more on how the grading systems work, see our Manuka honey grades explainer.
Is the honey organic?
Manuka honey is not usually officially certified as organic food. However, in high-quality production nothing is added artificially at any stage of the process. The remote farmland the bees forage is typically not sprayed with pesticides, herbicides, or insecticides, because the rugged, mountainous terrain is unsuitable for grazing animals.
Is Manuka honey 100% raw?
Genuine raw Manuka honey has nothing added at any stage of the production process. The product is essentially as it exists in the beehive after extraction — it has not been heated or pasteurised.
Why is Manuka honey so expensive?
Manuka honey is unique to New Zealand and comes from the Leptospermum scoparium tree, a native and limited resource. With a small window for harvest and honey that is difficult to extract, obtaining quality Manuka honey is a specialised task for beekeepers. Only around 2,800 tonnes of Manuka honey are produced each year, compared with roughly 1.9 million tonnes of other honey produced globally. Ongoing research continues to explore the properties of Manuka honey, which has contributed to its increasing global demand.
How can you tell if UMF™ Manuka honey is real?
Here is a checklist to help identify genuine UMF™ Manuka honey.
- The UMF™ trademark is clearly stated on the label.
- The honey is produced in New Zealand. Honey cannot be imported into New Zealand, so consumers can be assured that UMF™ Manuka honey is genuinely and only New Zealand Manuka honey.
- It is processed, packed, and labelled in New Zealand.
- It carries the New Zealand UMF™ licensee's brand name on the label (which also appears on the UMFHA website licensees list at umf.org.nz).
- It is produced by a New Zealand company licensed to use the UMF™ trademark.
- A grading number without the UMF™ abbreviation does not identify genuine UMF™ Manuka honey. There must be a rating number alongside the UMF™ trademark.
- It can be verified by the Official UMF™ Release Document, which states the test results for the batch number shown on the jar label. This document presents test results for all four Manuka markers (leptosperin, methylglyoxal, DHA, and HMF).
Beyond label checks, the wider scientific community has also developed independent analytical methods for verifying Manuka authenticity — such as the NMR-based marker testing mentioned above — which reinforces that genuine Manuka honey has a distinct, measurable chemical fingerprint, separate from any single brand's certification process.
How many calories are in a teaspoon of Manuka honey compared with refined sugar?
There are roughly 12 calories in a teaspoon of Manuka honey and 16 calories in a teaspoon of refined sugar. Manuka honey contains a range of naturally occurring nutrients compared with refined sugar, which contains none.
One area of ongoing laboratory research looks at Manuka honey's antioxidant capacity. In testing across a range of commercial samples rated from UMF 5+ to 18+, antioxidant capacity (measured using a standard chemical assay called FRAP) correlated strongly with both UMF rating and total phenolic content. This is an in-vitro chemical correlation across a limited set of graded samples, and on its own it does not demonstrate a clinical antioxidant benefit from eating or applying Manuka honey — but it does suggest that UMF grade may track with more than just antibacterial markers.
What do UMF™ 5+, 10+, 15+, 20+, 24+, and 26+ mean?
There are two components to the UMF™ grading system, both of which are stated on any UMF™ certified Manuka honey product.
- The label, which claims that it is Manuka.
- The number, which represents three chemical markers indicating the content of Manuka honey to help ensure quality and purity. The chemical markers are DHA, MGO, and leptosperin. See the UMFHA four-factor quality testing page for more information.
It is worth understanding what sits behind that number. As noted above, laboratory chemical analysis first identified methylglyoxal as the compound driving Manuka honey's characteristic non-peroxide antibacterial activity — this is the biochemical basis for why MGO features in grading systems at all.
That said, a higher UMF number does not always translate into stronger measured antibacterial performance in every batch. One laboratory study tested a limited sample of commercially purchased Manuka honeys of different UMF grades (5+, 10+, and 15+) against 128 bacterial isolates, and found that lower-graded honey sometimes performed equally well or better than higher-graded honey at inhibiting bacteria. This is preliminary in-vitro evidence from a small sampling and should not be read as showing that UMF grading is unreliable in general — grading systems remain a useful consumer safeguard — but it is a helpful reminder that antibacterial activity can shift over time (for example, as MGO levels change during storage), which is part of why proper storage and checking best-before dates matters.
Why are there different grading systems for Manuka honey?
There are six better-known grading systems for Manuka honey: Unique Manuka Factor (UMF™), Methylglyoxal (MGO), BioActive, KFactor, Molan Gold Standard (MGS), and Non-Peroxide Activity (NPA). Manuka honey has been used for many years, but it was only a few decades ago that Dr Peter Molan of the University of Waikato in New Zealand began documenting the properties of Manuka honey. Since then, organisations have been established to conduct extensive research into it. The UMFHA was founded in 1998 to research Manuka honey and to help protect both the industry and its consumers.
The UMF™ and MGO grading systems are among the oldest, most well established, and most widely recognised grading systems for Manuka honey in the world. Both trace back to the same underlying discovery — that methylglyoxal is the primary driver of Manuka's distinctive antibacterial activity — even though each organisation has developed its own testing and labelling approach. You can compare the systems in our Manuka honey grades explainer.
What grade of Manuka honey is suggested for a cut, abrasion, or wound?
UMF™ 10+ Manuka honey is often cited as a minimum for topical use.
For most healthy adults using food-grade or wound-care Manuka honey on minor cuts and abrasions, this general guidance reflects long-standing practice. However, people managing diabetes should take extra care. Because methylglyoxal — the very compound that gives Manuka honey its antibacterial strength — is also a known protein-glycating agent implicated in tissue damage associated with diabetes, at least one researcher has raised a theoretical, mechanism-based concern that Manuka honey's high MGO content could, in principle, contribute to processes that impair wound healing in people with diabetes. This is a hypothesis grounded in general biochemistry rather than a finding from a clinical trial in diabetic patients using Manuka honey, and the author explicitly calls for randomised controlled trials to test whether this risk plays out in practice. Anyone with diabetes should speak with a clinician before using Manuka honey products for wound care, rather than relying on general grade recommendations alone.
Can Manuka honey be taken during pregnancy?
For many years, women have consumed Manuka honey during pregnancy with no widely reported problems. As always, consult a healthcare professional as necessary.
On general oral safety, a small randomised, double-blind, cross-over clinical trial in 20 healthy adults aged 42–64 found that daily consumption of UMF 20+ Manuka honey for four weeks did not raise IgE (an allergy marker) or a marker of advanced glycation, and did not significantly change gut bacterial populations. This supports short-term consumption safety in healthy adults, but it is a small study that was not conducted in pregnant women, and it does not demonstrate a specific digestive health benefit. As always, anyone who is pregnant or breastfeeding should check with a healthcare professional before making Manuka honey a regular part of their diet.
Can my infant eat Manuka honey?
No. It is not safe for infants under 12 months old to consume Manuka honey, or any honey. Honey can contain spores that a baby's immature gut is not yet able to fight off, which can cause infant botulism.
How long will Manuka honey keep?
Honey is remarkably long-lasting. As long as it is stored properly — out of direct sunlight, away from direct heat, and not frozen — it will last well beyond its best-before date. For general quality and peace of mind, it is sensible to consume your honey within around three years of opening.
The UMF™ grading and activity levels in the honey will decline over time. Genuine UMF™ Manuka honey is typically guaranteed to hold its certified activity levels until at least the expiry date stated on the jar. As the laboratory research on UMF grades and antibacterial variability suggests, proper storage is not just about taste and texture — it also helps protect the active compounds that the grading system is designed to measure.
What can I do if my honey has turned granular?
If your honey becomes gritty and sugar-like, there is no need to worry. It is perfectly fine to consume and does not mean it is poor quality or has been adulterated. Honey can naturally crystallise, particularly when the weather turns cooler. Simply place the jar in a warm area, or gently apply warmth. This will soften the honey and transform the crystals back into the smooth, runny honey we love.
Why is some Manuka honey creamed?
When honey comes directly from the hive it is liquid. After a period of time, it will start to granulate. Producers control this granulation by creaming the Manuka honey. Once the honey changes state from liquid to solid, it will not reverse and is very stable.
Does Manuka honey have any dental benefits?
This is an area of early but interesting research. A small pilot clinical trial (30 volunteers, over 21 days) found that chewing a UMF 15 Manuka honey confectionery reduced dental plaque scores and gum bleeding compared with chewing sugarless gum. As a pilot study with a small sample size and short duration, this is preliminary clinical evidence rather than an established dental health benefit, and it would need to be confirmed in larger trials. It is also worth noting that this type of confectionery contains both sugar and honey, so it is not recommended for children under 12 months of age, and general dental hygiene advice from a dentist should still be followed.