Methylglyoxal (MGO)

Honey

Definition

The primary antibacterial compound in Manuka honey, responsible for its non-peroxide antimicrobial activity. MGO forms naturally from the conversion of dihydroxyacetone (DHA), a compound found in Manuka flower nectar, over time as the honey ages.

The Active Ingredient

Most honeys derive their antimicrobial activity from hydrogen peroxide, produced by the enzyme glucose oxidase when honey is diluted. Manuka honey has this peroxide activity too, but its claim to fame is an additional, non-peroxide antibacterial system powered primarily by methylglyoxal (MGO). This compound was identified as the dominant non-peroxide antibacterial agent in Manuka honey by Professor Thomas Henle at the University of Dresden in 2008.

How MGO Forms

MGO is not present in fresh Manuka nectar. Instead, Manuka flower nectar contains unusually high concentrations of dihydroxyacetone (DHA), a simple compound that slowly converts to MGO through a non-enzymatic chemical reaction over weeks and months after the honey is harvested. This means that Manuka honey's antibacterial potency actually increases as it ages, reaching peak MGO levels approximately 12 to 18 months after harvest. It is one of the few foods that becomes more bioactive with time.

MGO vs. UMF

MGO ratings and UMF ratings measure related but different things. MGO ratings (expressed as mg/kg) measure the concentration of methylglyoxal directly. UMF ratings assess overall antibacterial activity through a multi-marker test. A rough equivalence: MGO 100+ corresponds approximately to UMF 5+, MGO 250+ to UMF 10+, MGO 400+ to UMF 13+, MGO 550+ to UMF 15+, and MGO 850+ to UMF 20+.

Frequently Asked Questions

Is MGO found in other honeys?

Trace amounts of MGO are found in many honeys and some other foods. However, the concentrations in Manuka honey are 10 to 100 times higher than any other common honey variety, making Manuka unique in its non-peroxide antibacterial strength.

Does heating destroy MGO?

MGO is heat-stable and is not destroyed by normal storage temperatures or gentle warming. However, extreme heat can degrade some of the other beneficial compounds in Manuka honey. Gentle warming (below 104 degrees Fahrenheit) to reliquefy crystallized Manuka honey is safe and does not affect MGO levels.