What's in MGO? Composition, effects, and a guide to choosing

What does MGO contain? Understanding the key molecule in Manuka honey

The term MGO (methylglyoxal) has become familiar to consumers interested in Manuka honey and its benefits. This detailed article explains what MGO is, where it comes from, what substances it contains, its known health effects, scientific limitations, and how to choose a safe product that suits your needs.

Scientific definition of MGO

MGO, or methylglyoxal, is a reactive organic compound (a dicarbonyl) that occurs naturally in some foods. In Manuka honey, MGO is the main constituent responsible for its non-peroxide antibacterial activity. It is formed from dihydroxyacetone (DHA), a precursor abundant in the nectar of Leptospermum scoparium (Manuka) flowers.

Origin and formation

The biochemical chain is as follows: nectar rich in DHA is transformed into MGO by non-enzymatic reactions during honey maturation and storage. The MGO content therefore depends heavily on the floral origin, the processing conditions, and the storage conditions (temperature, duration).

Chemical composition associated with MGO

MGO does not come alone: ​​Manuka honey contains a complex matrix of compounds that play a synergistic role or modulate its activity.

Main components

• MGO (methylglyoxal): reactive molecules responsible for a major part of the non-enzymatic antibacterial activity.
• DHA (dihydroxyacetone): precursor present in nectar, influences the subsequent formation of MGO.
• Leptosperin: botanical marker of Manuka, useful for authenticating origin.
• Hydrogen peroxide (peroxide activity): present in many honeys but often less dominant in Manuka when MGO is high.
• Phenolics and flavonoids: contribute to the antioxidant and modulating properties of antimicrobial activity.
• Sugars, enzymes and minerals: nutritional basis and physicochemical influence (osmolarity, pH).
• HMF (hydroxymethylfurfural): indicator of excessive heating or aging of honey, to be monitored.

Concentrations and units

MGO is expressed in mg/kg or simply mg per kilogram of honey. Labels may indicate, for example, MGO 100+, 250+, 400+, etc. These values ​​reflect the measured concentration and serve as an indicator of non-enzymatic antibacterial strength.

Biological effects and scientific evidence

Several studies have shown that MGO possesses in vitro antibacterial activity against a broad spectrum of bacteria, including some resistant strains. However, extrapolating these effects to the clinical setting requires caution: local concentration, tissue availability, and metabolism influence efficacy.

Documented applications

• Topical use: dressings and wound care where MGO-rich Manuka honey can help reduce bacterial load.
• Oral use: some oral health formulations utilize antibacterial activity.
• Food use: consumption as a functional food for general well-being, without guarantee of therapeutic efficacy for specific pathologies.

Limitations and precautions

MGO is reactive and can cause chemical changes in vitro. At high doses, some carbonyl derivatives (such as methylglyoxal) can be cytotoxic in cell models. Caution is advised for diabetics (due to the sugar in honey), infants (under 1 year old), and immunocompromised patients. Honey rich in MGO should not replace prescribed medical treatment.

How is MGO measured and certified?

Laboratories quantify MGO by high-performance liquid chromatography (HPLC) after derivatization. Recognized labels (UMF, MGO grading) provide information: UMF is a registered trademark that includes tests for authenticity and activity, while MGO values ​​indicate the measured chemical concentration.

What guarantees should you look for on the label?

• Explicit MGO value (e.g., MGO 250+).
• Authenticity mark or certification (UMF, independent laboratory test).
• Harvest date and batch number for traceability.
• HMF value or indication of no overheating.

FAQ — Frequently Asked Questions

Is MGO dangerous?

For general dietary use, the MGO present in Manuka honey is considered safe for most adults. However, adverse effects may occur with excessive consumption, and there are contraindications for certain groups (infants, unsupervised diabetics).

What is the difference between UMF and MGO?

UMF (Unique Manuka Factor) is a trademark that includes activity tests and analyses for authenticity. MGO is simply the chemical measure of methylglyoxal. The two are complementary: MGO provides an objective value, while UMF assesses overall activity.

Is a high MGO content always better?

Not necessarily. A higher concentration means more MGO, but not automatically better suitability for your needs. For everyday use, a moderate MGO level may be sufficient. For topical applications, higher concentrations are sometimes chosen, but only with professional advice.

How to choose a product rich in MGO

When selecting a Manuka honey or a supplement containing MGO, consider the following points:

• Look for a clearly stated MGO value and a UMF certification or independent laboratory report.
• Check the traceability (country of origin, harvest date, batch).
• Avoid products with prices that are too low, as they may be diluted or adulterated.
• Consider the end use: daily nutrition vs. localized treatment.

Usage and storage instructions

Store honey away from heat and light to limit the degradation of MGO and the increase in HMF. Avoid heating honey to high temperatures. Consume in reasonable amounts: honey is a concentrated sugar.

Conclusion

What does MGO contain? Primarily methylglyoxal, produced from DHA, and accompanied by a matrix rich in compounds that together determine the activity and quality of Manuka honey. MGO is a key indicator of non-enzymatic antimicrobial activity, but it must be considered within its overall context (quality, safety, use).

• Consult the scientific studies listed in the resources section for further reading.
• Ask your questions to a pharmacist or nutritionist if you have specific conditions.