Mānuka honey is not like other honey. What sets it apart is a compound called methylglyoxal, or MGO. MGO stands for methylglyoxal, a naturally occurring compound that gives Mānuka honey its exceptional antibacterial properties. The MGO rating on a jar of Mānuka honey indicates the concentration of methylglyoxal in milligrams per kilogram (mg/kg). The higher the number, the stronger the antibacterial activity. Understanding what MGO is, where it comes from, and how to choose the right level is essential to getting the most from your Mānuka honey.
How MGO Forms in the Mānuka Bush
Methylglyoxal in Mānuka honey originates in the nectar of the Mānuka bush (Leptospermum scoparium), a flowering plant native to New Zealand. The nectar is rich in a compound called dihydroxyacetone (DHA). During the honey-making process, DHA undergoes a gradual chemical transformation and converts into methylglyoxal. This conversion continues over time, which is why properly stored Mānuka honey can increase in MGO concentration as it matures.
What makes this significant is that MGO is highly stable. Unlike the antibacterial activity in conventional honey, which relies on hydrogen peroxide and degrades in the presence of heat, light, and certain enzymes, MGO retains its potency. This stability is what gives Mānuka honey its reliable, measurable antibacterial effect.
What the MGO Rating Tells You
The MGO rating on a jar of Mānuka honey tells you exactly how much methylglyoxal is present, measured in milligrams per kilogram (mg/kg). An MGO 300+ rating means the honey contains at least 300 mg of methylglyoxal per kilogram. The higher the number, the greater the antibacterial potency.
This rating system provides a transparent, independently verifiable measure of strength. When you buy Mānuka honey with a certified MGO rating, you have a concrete basis for comparing products and selecting the right one for your needs.
MGO vs UMF Rating: Understanding Both Systems
Two grading systems are widely used to measure Mānuka honey quality: MGO and the Unique Mānuka Factor (UMF). Both are scientifically grounded, but they measure slightly different things.
MGO measures the concentration of methylglyoxal directly. This is a precise, single-compound measurement.
UMF is a broader quality mark used by the UMF Honey Association. A UMF rating measures three chemical markers: leptosperin, DHA, and methylglyoxal. Leptosperin is found exclusively in Mānuka nectar, making it a key authenticity marker. DHA indicates freshness and the potential for further MGO development. The UMF system therefore, verifies both potency and origin.
The two systems correlate broadly: UMF 10+ corresponds approximately to MGO 263+, and UMF 20+ to MGO 829+. Neither system is inherently superior. MGO is the more direct measure of antibacterial strength, while UMF provides a wider authenticity check. Many products, including those from Melora, are independently tested against both standards.
Health Benefits of MGO in Mānuka Honey
Research into methylglyoxal has established a number of documented health benefits, particularly in antibacterial and wound-care applications.
Antibacterial action: MGO inhibits bacterial growth, including methicillin-resistant Staphylococcus aureus (MRSA). Higher MGO concentrations produce stronger inhibition. This is the core property that gives Mānuka honey its clinical and therapeutic reputation.
Wound healing: Mānuka honey with significant MGO content creates a protective barrier over wounds, reducing the risk of infection while supporting the body's natural healing process. Its anti-inflammatory properties help to reduce swelling and discomfort at the wound site.
Sore throat and oral health: Taken internally, Mānuka honey can soothe sore throats and reduce harmful bacteria associated with plaque and gum disease.
Digestive support: Mānuka honey has been used to help alleviate symptoms of digestive discomfort, including gastric irritation.
When using Mānuka honey for a specific health condition, consult a healthcare professional before use. This is particularly important for those taking prescribed medications, as honey can interact with certain drugs.
Choosing the Right MGO Level
Selecting the right MGO level depends on your wellness goals. Here is a practical guide to the Melora range:
MGO 40+ (Gentle and Functional)
An accessible entry-level grade suited to everyday use, cooking, and gentle daily support. Despite its lower MGO concentration, MGO 40+ Mānuka honey carries medical-grade credentials and is trusted for applications requiring a soothing, protective quality. A good starting point for those new to Mānuka honey.
MGO 100+ (Everyday Wellness)
A step up in potency and a popular choice for daily wellness routines. MGO 100+ is well suited to general health maintenance and mild ailments such as seasonal sore throats. This grade sits comfortably within the range recommended for minor everyday support.
MGO 300+ (Advanced Support)
A high-grade honey with robust antibacterial activity. MGO 300+ is used in medical settings for wound care and infection support, valued for its combination of potency and gentleness. For consumers, it is appropriate where a higher antibacterial level is needed, such as persistent throat or digestive complaints.
MGO 525+ (High Strength)
Designed for targeted, specific health applications. MGO 525+ is favoured by those seeking a high-strength natural product for more demanding wellness goals. Typically used short term and for a defined purpose.
MGO 850+ (Ultimate Potency)
The highest strength in the Melora range. MGO 850+ offers maximum antibacterial activity and is reserved for short-term, targeted use where the greatest natural potency is required.
What Makes Genuine Mānuka Honey
Monofloral Mānuka Honey
Monofloral Mānuka honey is produced when bees gather nectar predominantly from the Mānuka bush, resulting in honey with a significantly higher MGO concentration and a distinct floral profile. Multifloral Mānuka honey, by contrast, is collected from a mix of New Zealand plants and carries lower MGO levels.
For therapeutic use, monofloral Mānuka honey is the appropriate choice. The concentration of DHA in the nectar, and by extension the MGO that forms from it, is substantially higher in monofloral honey than in blended varieties.
Chemical Markers and Independent Testing
Authenticity is verified through testing for specific chemical markers found only in genuine Mānuka: leptosperin, DHA, and methylglyoxal. These compounds confirm both that the honey is sourced from the Mānuka bush and that it has not been blended with other floral varieties.
Independent laboratory certification is essential when purchasing Mānuka honey. Products carrying a verified MGO or UMF certification have been tested against these markers, giving you confidence in both potency and origin. At Melora, every batch is independently tested before it reaches the shelf.
Beyond the Jar: MGO in Mānuka Skincare
The antibacterial and anti-inflammatory properties of high-MGO Mānuka honey extend beyond food and wellness applications. Topically applied Mānuka honey can help calm blemish-prone skin, reduce redness and irritation, and promote a clearer complexion. Melora incorporates Mānuka into a dedicated skincare range, delivering targeted antibacterial benefits directly to the skin.
Melora UK: Genuine Mānuka Honey from New Zealand's East Cape
Melora sources its Mānuka honey from the wild-harvested Mānuka of New Zealand's East Cape, a region recognised for producing honey with high DHA content and, in turn, elevated MGO concentrations. Every product is independently certified for MGO rating, and Melora works in partnership with Māori communities who have a centuries-long connection to the land and to the Mānuka bush.
Whether you are new to Mānuka honey or looking to select a higher-strength product for a specific purpose, Melora's range offers certified, transparent, and independently tested options from MGO 40+ to MGO 850+.
Explore the Melora Mānuka Honey range to find the right MGO level for your needs.
Conclusion
MGO is the measurable, scientifically verified compound that defines the antibacterial strength of Mānuka honey. Understanding the MGO rating, how it relates to the UMF system, and how to match a strength to your health needs allows you to make a confident, informed purchase. Genuine Mānuka honey, independently certified for MGO concentration and tested for key chemical markers, provides a reliable, natural option for wound care, everyday wellness, and topical skincare applications.