close Shopping Basket
ItemActivitySizeQUnit PriceRemoveSub Total
Clear Basket
Continue shopping
. Processing...
Continue To Payment


Unique Manuka Honey: What does the number mean?

Honey has been used for centuries for more than food because it inhibits bacterial and fungal infections. All honey has some of these properties because of peroxidal activities. Many companies measure this activity and label their honey as ACTIVE. Genuine Manuka Honey has 2 important advantages over other honey; its unique naturally occurring antibacterial effects are superior and they are stable in storage. Manuka Honey from New Zealand  is the only honey in the world with this effect.


5.1 text umf

The number of Manuka Honey is either a UMF® (Unique Manuka Factor) rating or a measure of the most important organic chemical contributing to the special antibacterial properties of Manuka Honey called Methylglyoxal - MG or MGO©.

UMF and MG are valid measures of the non-peroxidal activity unique to Manuka Honey. UMF measures the activity itself. MG or MGO© measures the compound responsible for a major component (but not all) of that activity. The MG number is much higher than the UMF number.

UMF® shows the relative effectiveness of Manuka Honey for inhibiting bacterial growth in direct comparison with the antiseptic phenol. The higher the UMF® number the greater the topical antibacterial effects.

The UMF® trademark is internationally verified. It guarantees authentic, unadulterated Manuka Honey. An independent laboratory determines the number. UMF® Honey must contain DHA (dihydroxyacetone), Leptosperin, and Methylglyoxal.

To receive a UMF® grading, a honey must have the presence of DHA, MGO and leptosperin. The UMF® rating is a measure of the attributes and values that make up manuka honey, and assures its purity and quality.


5.1 text UMF graph

Download UMF brochure

How did UMF arise?

Most honeys have antibacterial properties, the mechanisms suggested for these antimicrobial characteristics centre around the action of hydrogen peroxide that depends upon the floral and nectar sources. Other factors, such as acidity and the super saturated concentration of sugar, are also thought to affect its antimicrobial properties.

In contrast, manuka honey also shows non-peroxidal activity (NPA) that is the basis of the UMF® rating. It has been proposed that the higher the UMF factor the greater the antimicrobial potency1.

UMF is a New Zealand trademark (UMF®) developed to represent a standard of NPA antibacterial activity that is compared to the disinfectant phenol. However there is some controversy over whether consuming honey has any effect on bacteria; therefore, the New Zealand Government has instructed manuka honey producers that they cannot make health claims relating to antibacterial activity once consumed until further research is conducted. Below we discuss the original research.

According to van Eaton2, Professor Peter Molan's original test for the unique manuka factor (UMF) involved the plating out of batch samples of the honey, and seeing how the honey inhibited the growth of Staphylococcus aureus bacteria, and then comparing the ring of inhibition with the size of the ring produced by phenol. The rating was a direct reference back to the concentration of phenol (5+ was equivalent to 5% phenol, 10+ was 10% etc).

Phenol (carbolic acid) was extracted from coal tar. Joseph Lister, the pioneer in early methods of human surgery, used it in the first antiseptic surgeries starting in 1867. The higher the concentration of phenol, the stronger the antibacterial activity and antiseptic properties.

UMF® and MGO

Both UMF and MGO are valid measures of non-peroxide activity of manuka honey. UMF measures the activity itself, whereas MGO measures the major compound producing that activity.


1. SummerGlow Apiaries Ltd. (2009) What is UMF?

2. Van Eaton C. (2014) Manuka. The biography of an extraordinary honey. Exisle Publishing.