Manuka Honey UMF and MGO Ratings Explained
What the UMF and MGO numbers on manuka honey are meant to measure, what lab research links them to, what they do not tell you, and how fraud and mislabeling are checked.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read natural ingredient safety before you use anything on this page.
Manuka honey, like all honey, is not for babies under 12 months. See Honey and Infant Botulism.
The question
Jars of manuka honey carry numbers such as "UMF" or "MGO." What do they mean, and do higher numbers mean better health results? The sources we read explain the chemistry. They do not show that higher numbers give better results in people eating the honey.What manuka honey is
Manuka honey is a dark honey made from the nectar of the flowers of Leptospermum scoparium, the plant called mānuka in New Zealand. [1][2] Australia has more than 80 Leptospermum species, and a study of 80 Australian honeys found some with antibacterial activity similar to New Zealand manuka. [3] The plant name is worth checking on a label, because "manuka" is not the only honey from this plant family.How the sources define the terms
- MGO (methylglyoxal): a chemical measured in the honey, reported in milligrams per kilogram in the Australian study. [3] It comes from another compound, dihydroxyacetone (DHA), found in manuka nectar; stored honey showed DHA falling and methylglyoxal rising when held at 37 °C. [4]
- UMF (Unique Manuka Factor): a rating reported by one overview to be related to antibacterial potency and to correlate with methylglyoxal and total phenol content. [1] The exact grading rules and the body that runs the rating system are not described in the sources we read, so we do not explain grade cut-offs here.
- NPA (non-peroxide antibacterial activity): a lab measure of antibacterial strength that does not depend on hydrogen peroxide. In the Australian study it had a strong positive relationship with MGO. [3]
What research found
| Question | What the source found | Strength of evidence |
|---|---|---|
| Does MGO explain manuka's lab antibacterial activity? | The activity of manuka honey is largely due to MGO, and in 80 Australian samples NPA and MGO were strongly related. [3] | Laboratory only |
| Does the number predict benefit in people? | Proper evidence not found. We searched PubMed for manuka honey grading, UMF and MGO and found lab and chemistry papers, not trials linking grade to health outcomes in people who eat or use the honey. | Insufficient evidence |
| Are grading systems settled? | A 2024 review lists manuka honey grading, safety and efficacy, implied benefits and maximum contaminant levels among controversial topics. [2] | Review |
| Does stored honey keep its activity? | NPA was stable in most samples after seven years stored in the dark at 4 °C. [3] | Laboratory only |
Lab activity against bacteria does not show that eating the honey, or putting it on skin, treats any condition. For wound products tested in trials, see Medical-Grade Honey and Wound Care.
Fake or mislabeled manuka
- A review says manuka honey sells for 6 to 25 times the price of other honeys, and that increased demand led to more fraud. [5]
- New Zealand researchers describe combining chemical markers from nectar and DNA from pollen to authenticate manuka honey. [6]
- Reviews describe laboratory methods (mass spectrometry, nuclear magnetic resonance, fluorescence) for finding adulteration. [5] A shopper cannot do this at home.
What a reader can do: read the label and the producer's information about how the number was measured, and ask a pharmacist if buying for a medical reason. This page does not rank products. For label basics, see Natural Ingredient Quality and Labels. For the full manuka overview, see Manuka Honey.
Frequently asked questions
What does MGO mean on manuka honey?
It stands for methylglyoxal, a compound that forms from dihydroxyacetone in manuka nectar and is linked to the honey's antibacterial activity in the lab. [4][3]
What does UMF mean?
Unique Manuka Factor, a rating one overview says correlates with methylglyoxal and total phenols. [1] The grading rules are not described in the sources we read.
Is a higher number better for my health?
Proper evidence not found. The sources show lab links to antibacterial activity, not benefit in people. [3]
How can I spot fake manuka honey?
You cannot reliably do so by taste or look. Reviews describe lab testing for authenticity. [5]
Is manuka honey safe for babies?
No. Honey is not for babies under 12 months. [10]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety
References
- Antibacterial activity of Manuka honey and its components: An overview. AIMS Microbiol 2018. PubMed 31294240. Read 2026-10-22.
- An updated review of functional ingredients of Manuka honey and their value-added innovations. Food Chem 2024. PubMed 38211407. Read 2026-10-22.
- The Antibacterial Activity of Australian Leptospermum Honey Correlates with Methylglyoxal Levels. PLoS One 2016. PubMed 28030589. Read 2026-10-22.
- The origin of methylglyoxal in New Zealand manuka (Leptospermum scoparium) honey. Carbohydr Res 2009. PubMed 19368902. Read 2026-10-22.
- The super-food Manuka honey, a comprehensive review of its analysis and authenticity approaches. J Food Sci Technol 2022. PubMed 35734106. Read 2026-10-22.
- Using chemical and DNA marker analysis to authenticate a high-value food, manuka honey. NPJ Sci Food 2018. PubMed 31304259. Read 2026-10-22.
- Association between honey consumption and infant botulism. Pharmacotherapy 2002. PubMed 12432974. Read 2026-10-22.
- Ensuring the Safe Use of Bee Products: A Review of Allergic Risks and Management. Int J Mol Sci 2025. PubMed 41465502. Read 2026-10-22.
- Honey as a Natural Flavorful Product: A Comprehensive Review of Its Potential Biological Activities and Recent Studies. Food Sci Nutr 2026. PubMed 42005332. Read 2026-10-22.
- World Health Organization. Botulism fact sheet. Read 2026-10-22.