The UMF property is naturally present in the nectar of some Manuka flowers in varying strengths. Laboratory studies have shown that UMF Manuka honey is totally effective against a wide range of very resistant bacteria including major wound-infecting bacteria and the stomach ulcer causing bacteria helicobacter pylori. UMF is a registered trade mark and can only be used by licensed users who meet set criteria. The name UMF is followed by a number that indicates the strength of the UMF antibacterial property in a batch of UMF Manuka honey tested in our licensed laboratory after the honey has been packed.