What is the Antibacterial Rating of Manuka Honey?

December 27, 2025 •

4 min read

Did you know that Manuka honey was approved by the U.S. Federal Drug Administration in 2007 as a treatment for wounds? This unique honey's potent antibacterial properties are measured by specific rating systems, helping consumers and medical professionals determine its strength and authenticity.

Quick Summary

The antibacterial potency of Manuka honey is measured using rating systems like UMF and MGO, which indicate the concentration of key compounds like methylglyoxal.

Key Points

MGO (Methylglyoxal) is the key antibacterial compound in Manuka honey, responsible for its potent non-peroxide activity.
UMF™ (Unique Manuka Factor) is a comprehensive quality trademark that verifies the honey's authenticity and potency by measuring MGO, DHA, Leptosperin, and HMF.
Higher ratings typically indicate stronger antibacterial activity, but the ideal rating depends on your intended use, from daily wellness to targeted therapeutic applications.
Manuka honey's antibacterial action is multifactorial, involving MGO, low pH, osmotic effect, and other compounds, making it difficult for bacteria to develop resistance.
Medical-grade Manuka honey is recommended for wound care, as it is gamma-irradiated to remove botulism spores and safely supports healing, even on antibiotic-resistant infections.
MGO-only ratings indicate potency but not authenticity, whereas UMF™ certification provides a more robust guarantee of quality and origin.

Decoding the Antibacterial Powerhouse: MGO and UMF

Manuka honey, a monofloral honey from New Zealand, is globally recognized for its exceptional antibacterial properties. Unlike regular honey, whose antibacterial activity comes from hydrogen peroxide, Manuka honey's potency primarily stems from a powerful compound called methylglyoxal (MGO). To help consumers and medical professionals understand and compare its strength, two main rating systems are used: MGO and UMF™ (Unique Manuka Factor).

The MGO Rating: A Direct Potency Measure

The MGO rating is a simple, direct measurement of the methylglyoxal content present in the honey, expressed in milligrams per kilogram (mg/kg). MGO is formed from dihydroxyacetone (DHA), a precursor compound found in the nectar of the Manuka flower. As the honey matures, DHA converts into MGO, increasing its potency. A label of MGO 400+ means the honey contains a minimum of 400 mg of methylglyoxal per kilogram.

Common MGO Strength Levels and Uses:

MGO 83+ / UMF 5+: This is considered a lower-potency, 'table-grade' honey suitable for general wellness and daily consumption.
MGO 263+ / UMF 10+: A mid-range, 'therapeutic-grade' honey often used for boosting immunity, soothing sore throats, or supporting digestive health.
MGO 514+ / UMF 15+: This is a premium antibacterial-grade honey with higher potency, commonly used for targeted therapeutic applications like wound care and skincare.
MGO 829+ / UMF 20+ and above: Considered a superior antibacterial-grade honey for more serious skin conditions or stubborn infections.

The UMF™ Rating: The Comprehensive Gold Standard

The UMF™ rating system, managed by the UMF™ Honey Association, is considered the most comprehensive and stringent grading standard. It provides a more robust guarantee of the honey's authenticity, purity, and potency by measuring four key markers, not just MGO.

The Four Key UMF Markers:

Methylglyoxal (MGO): The primary antibacterial compound, measured for potency.
Dihydroxyacetone (DHA): The precursor to MGO, indicating the potential shelf life and potency stability.
Leptosperin: A unique compound found exclusively in Manuka nectar, which confirms the honey's floral origin and authenticity.
Hydroxymethylfurfural (HMF): A heat-sensitive chemical indicating freshness. Low HMF levels ensure the honey has not been overheated.

The Science Behind Manuka's Antibacterial Action

Manuka honey's effectiveness against a wide range of pathogens, including antibiotic-resistant strains like Methicillin-resistant Staphylococcus aureus (MRSA), is well-documented. Its multifactorial mechanism of action makes it difficult for bacteria to develop resistance.

Key antibacterial mechanisms include:

High Sugar Content (Osmotic Effect): The honey's high sugar concentration and low water content create an osmotic pressure that dehydrates and kills bacteria.
Low pH: The natural acidity of honey creates an unfavorable environment for bacterial growth.
Methylglyoxal (MGO): This key compound interferes with the bacteria's cell division, altering cell morphology and inhibiting growth.
Other Bioactive Compounds: Flavonoids, phenolic acids, and bee defensin-1 also contribute to the honey's overall antimicrobial activity, often in synergistic ways.

Comparing Manuka Honey Ratings

Choosing between MGO and UMF™ can be confusing, but understanding their differences helps. MGO offers a clear and direct measurement of the primary antibacterial component, while UMF™ provides a more thorough and independently verified assurance of authenticity, quality, and multiple active markers.


Feature	MGO Rating	UMF™ Rating
Focus	Primarily on Methylglyoxal (MGO) content.	A comprehensive measure of four key markers: MGO, DHA, Leptosperin, and HMF.
Measurement	Milligrams of MGO per kilogram (mg/kg).	A scale from 5+ to 32+ based on multiple factors.
Assurance	Indicates potency level, but does not guarantee authenticity or origin.	Guarantees honey is genuine, potent, pure, fresh, and from New Zealand.
Verification	Can be tested anywhere, though reputable companies use certified labs.	Independently verified and monitored by the UMF™ Honey Association.
Typical Use	Often used for brands to highlight antibacterial strength.	Considered the industry 'gold standard' for quality.

How to Choose the Right Rating for Your Needs

Your choice of Manuka honey and its rating depends on your intended use. For everyday wellness, lower grades offer a beneficial health boost. For targeted therapeutic use, higher ratings are more suitable.

For daily immune support, digestion, or as a healthy sweetener, a UMF 5+ to 10+ or an MGO 83+ to 263+ is generally sufficient.
For more targeted uses, such as soothing a sore throat, addressing mild skin conditions like acne, or supporting general immune health, opt for a mid-range UMF 10+ to 15+ or MGO 263+ to 514+.
For wound care, healing burns, or treating more persistent bacterial infections, a higher-potency medical-grade Manuka honey, such as UMF 15+ or 20+, is recommended. Always use medical-grade honey for topical applications.

Conclusion

The antibacterial rating of Manuka honey is determined by its concentration of methylglyoxal (MGO) and confirmed through the comprehensive UMF™ quality trademark. Understanding these rating systems is key to purchasing a product that meets your needs for potency and authenticity. While MGO provides a direct measure of the primary antibacterial component, the UMF™ certification offers a more thorough assurance by also testing for authenticity and freshness markers. For targeted medicinal purposes like wound healing, higher-rated, medical-grade Manuka honey has demonstrated significant efficacy, even against antibiotic-resistant bacteria. For everyday wellness, lower ratings provide a sufficient and beneficial health boost. Ultimately, choosing a honey with clear and verified ratings from a reputable brand ensures you receive the full potential of this powerful natural remedy. Read more about the antibacterial activity of Manuka honey and its components in this review from the AIMS Microbiology journal.

Frequently Asked Questions

MGO measures only the concentration of methylglyoxal, the key antibacterial compound, in mg/kg. UMF is a more comprehensive system that measures MGO alongside other markers like DHA and Leptosperin to confirm the honey's authenticity, potency, and freshness.

Higher ratings indicate greater antibacterial potency, which is better for targeted therapeutic uses like treating wounds. However, for daily wellness, a mid-range rating like UMF 10+ or MGO 263+ is often sufficient and more cost-effective.

For wound care, a higher potency is more beneficial. Look for medical-grade Manuka honey with a high UMF rating, typically UMF 15+ or 20+. The honey should be gamma-irradiated to ensure it's safe for deep wounds.

The MGO content in Manuka honey can increase over time as the precursor compound, DHA, naturally converts. This gives it a long shelf life, and the UMF system even checks for this process.

Yes, in vitro studies and clinical reports have shown Manuka honey to be effective against antibiotic-resistant strains, including MRSA. Its multi-component mechanism of action prevents bacteria from developing resistance.

To ensure authenticity, look for a certified UMF™ trademark and license number on the label. This guarantees the honey meets New Zealand's strict quality standards. Also, look for a batch number and ensure the honey is packaged in New Zealand.

Manuka honey is safe for children over one year old. However, honey should never be given to infants under 12 months due to the risk of botulism.