Glossary
A direct measurement of methylglyoxal concentration in Manuka honey, expressed in milligrams per kilogram (mg/kg). MGO is the compound primarily responsible for Manuka honey's unique non-peroxide antibacterial activity, and the MGO rating provides a straightforward way to compare product potency.
MGO 30-80: minimal activity, suitable for general dietary use. MGO 100-250: moderate activity, good for daily wellness. MGO 250-400: significant activity, suitable for immune support and mild therapeutic use. MGO 400-550: high activity, appropriate for direct wound application and intensive immune support. MGO 550+: very high activity, medical-grade potency.
Approximate UMF equivalents: MGO 83 = UMF 5, MGO 263 = UMF 10, MGO 514 = UMF 15, MGO 829 = UMF 20. Higher MGO means higher price, so match your purchase to your intended use rather than automatically buying the highest available.
Methylglyoxal forms naturally in Manuka honey through the non-enzymatic conversion of dihydroxyacetone (DHA), a compound found in the nectar of Leptospermum scoparium flowers. This conversion continues slowly after harvest, meaning freshly harvested Manuka honey may test at a lower MGO than the same honey tested months later.
This ongoing conversion is why DHA testing is included in UMF certification but not in standalone MGO rating. DHA testing predicts future MGO potential, providing a more complete quality picture.
Higher MGO means stronger antibacterial activity but also higher cost. For daily eating and general wellness, MGO 100-250 provides meaningful benefits at reasonable cost. Reserve MGO 400+ for specific therapeutic applications where maximum potency is needed.
Unfortunately yes, and this is a concern in the Manuka industry. Synthetic MGO can be added to boost ratings fraudulently. This is why UMF certification (which tests multiple markers including authenticity indicators) provides more reliable quality assurance than MGO alone.
Yes. MGO levels typically increase for 1-2 years after harvest as DHA continues converting to MGO. After peak conversion, MGO remains relatively stable for years in properly stored honey.
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