Methylglyoxal in Honey: What MGO Numbers Mean on a Label
Methylglyoxal in honey is the reason manuka jars carry numbers like MGO 263+ or MGO 514+. It is a small, reactive compound that builds up in honey from one unusual flower, and it drives much of manuka's activity in lab tests. This article explains where methylglyoxal comes from, why it rises over time, what label numbers measure, and how to think about it if you are deciding between manuka and other honeys. Our manuka honey alternative guide covers the shopping side.
For general education only, not medical advice. Our honey is a food and is not intended to diagnose, treat, cure or prevent any disease.
Where methylglyoxal in honey comes from
In 2009 researchers in New Zealand published a study on the origin of methylglyoxal in manuka honey. They found that fresh manuka honey contains little methylglyoxal but plenty of dihydroxyacetone, or DHA, which comes from the nectar of the manuka bush.
Over time, DHA in the honey slowly converts into methylglyoxal. A follow-up study looked at how that conversion happens and how storage conditions affect it.
Most other honeys, including clover, wildflower and buckwheat, contain only small amounts of methylglyoxal because their nectar does not carry much DHA.
What MGO numbers on labels mean
An MGO number is a measured concentration of methylglyoxal in milligrams per kilogram of honey. A jar labeled MGO 100+ was tested at or above that level. Higher numbers usually mean higher prices.
Some brands use other grading systems, such as UMF, which combine several markers. Reading the fine print helps, because the same jar can carry more than one kind of rating.
| Label term | What it measures |
|---|---|
| MGO | Methylglyoxal, in mg per kg |
| DHA | Dihydroxyacetone, the precursor that becomes MGO |
| UMF | A trademarked grade based on several manuka markers |
| NPA | Non-peroxide activity measured in a lab test |
What research says about MGO
Lab studies link methylglyoxal to much of manuka honey's antibacterial activity in a dish, which is why manuka is described as having non-peroxide activity. Other honeys rely more on hydrogen peroxide in honey for their lab activity.
Cleveland Clinic notes that much of the research interest in manuka involves sterilized medical-grade products used under professional care. That is very different from eating a spoonful from the pantry.
Human studies on eating manuka for any specific benefit remain limited. Methylglyoxal is also a compound the body produces on its own during normal metabolism, and scientists are still studying how dietary MGO is handled.
Is a high MGO number better?
For lab activity, higher MGO generally tests stronger. For eating, there is no clear evidence that a higher number brings any extra benefit. Taste matters too, and very high-MGO manuka can taste intensely medicinal to some people.
If you simply want a rich, dark honey for tea and toast, a darker American honey can be a flavorful and more affordable choice. Our comparison of buckwheat vs manuka honey covers this in detail.
Points to keep in mind when shopping
A few practical notes if you are comparing jars:
- MGO applies mainly to manuka and a few related honeys from the same plant family.
- Look for independent test results rather than marketing words alone.
- Price tends to rise steeply with each MGO step.
- No honey, at any MGO level, is safe for babies under 12 months.
How storage changes methylglyoxal in honey
Because methylglyoxal in honey forms from DHA over time, manuka producers often store their honey for months before testing and labeling it. Warmer storage speeds up the conversion, but too much heat also creates other compounds that can count against honey quality.
Researchers studying the formation of methylglyoxal from dihydroxyacetone found that the conversion is slow and only partial. Not every molecule of DHA becomes MGO, which is one reason labels can be hard to compare between brands.
Once the honey is in your kitchen, methylglyoxal in honey stays fairly stable at room temperature. There is no benefit to warming the jar on purpose.
Methylglyoxal in honey and taste
High levels of methylglyoxal in honey are linked with manuka's strong, earthy, slightly medicinal taste. Many people love it. Others find it too intense for everyday use in tea or on toast.
If you are buying mainly for flavor, it is worth tasting a low-MGO jar before investing in a high-MGO one. You may also find that a robust honey from another flower gives you the depth you want for a fraction of the price.
Our knotweed vs buckwheat honey comparison is a good place to explore bold American honeys.
Our honeys and MGO
Al Safa honeys come from American flowers like buckwheat, clover and wildflower, so we do not sell manuka or advertise MGO levels. What we offer is raw honey that is never heated above hive temperature and strained only of wax.
If you are drawn to manuka for its bold taste, try a dark jar from our shop, and read dark honey benefits to learn why darker honeys are studied so often.
Sources
Outside health sources we used for this article. They open in a new tab.
Frequently asked questions
- Is methylglyoxal only found in manuka honey?
- Small amounts appear in many foods and honeys, but high levels are typical of manuka because its nectar is rich in dihydroxyacetone, which turns into methylglyoxal over time.
- Does MGO increase as honey ages?
- Yes, as DHA converts into methylglyoxal during storage. The rate depends on temperature and time.
- What MGO level should I buy?
- There is no proven best level for eating. Choose based on taste and budget, and be wary of health promises tied to a number.
- Does Al Safa sell manuka honey?
- No. We sell eight raw American honeys and a sampler. Our darkest jars, buckwheat and knotweed, are popular with people who like bold honey.
- Does methylglyoxal in honey break down with heat?
- MGO is fairly stable, but heating honey creates other compounds and harms delicate ones. There is no reason to heat manuka or any honey on purpose.
Al Safa Honey is a food producer, not a medical provider. Nothing here is medical advice, and these statements have not been evaluated by the Food and Drug Administration. Talk to your doctor about any health concern. Never give honey of any kind to a baby under 12 months old.