How to Choose Manuka Honey: UMF® Ratings, MGO & Strengths Explained

Choosing Manuka honey can be surprisingly confusing.

One jar may say UMF® 5+, another UMF® 10+ or 15+, while another brand may promote an MGO number instead. Prices can also vary considerably between different strengths, leaving many people wondering whether a higher number necessarily means a better honey.

The good news is that choosing Manuka honey becomes much easier once you understand what the ratings actually tell you.

This guide explains the difference between UMF® and MGO, what the different Manuka honey strengths mean, how genuine New Zealand Manuka honey is authenticated, and how to choose an appropriate grade without simply buying the highest — and most expensive — number available.

What Is Manuka Honey?

Manuka honey is produced when bees collect nectar from the flowers of the New Zealand Manuka plant (Leptospermum scoparium).

While all honey contains a complex mixture of naturally occurring compounds, New Zealand Manuka honey has attracted considerable scientific interest because of its distinctive chemical composition and bioactive components.

For Manuka honey exported from New Zealand, authenticity is not simply a marketing claim. New Zealand's Ministry for Primary Industries (MPI) has established a scientific definition based on four chemical markers and one DNA marker. Honey labelled as Manuka for export must meet this definition.

This provides an important starting point when choosing Manuka honey: origin and authenticity matter just as much as the number printed on the jar.

What Does UMF® Mean?

UMF stands for Unique Manuka Factor.

The UMF™ system is an independent certification and grading programme specifically for New Zealand Manuka honey. Rather than measuring only one compound, UMF certification examines several characteristics of the honey.

The UMF quality system assesses important factors including:

• MGO (methylglyoxal) — associated with the honey's characteristic activity and potency.
• Leptosperin — a naturally occurring compound associated with Manuka nectar and used as an authenticity marker.
• DHA (dihydroxyacetone) — a naturally occurring precursor involved in the development of MGO over time.
• HMF (hydroxymethylfurfural) — monitored as an indicator of honey quality, freshness and excessive heating or ageing.

This is why UMF is more than an activity number. It provides a broader quality-assurance system covering authenticity, potency, freshness and quality.

What Does MGO Mean?

MGO stands for methylglyoxal, one of the naturally occurring compounds associated with Manuka honey's distinctive antibacterial activity.

An MGO number indicates the concentration of methylglyoxal in the honey, generally expressed in milligrams per kilogram.

In simple terms, a higher MGO number indicates a higher concentration of methylglyoxal.

There is, however, an important distinction:

MGO measures one component. UMF® certification assesses a broader set of characteristics.

An MGO number alone should therefore not be regarded as equivalent to full UMF certification.

UMF® vs MGO: What's the Difference?

The easiest way to think about the two is:

MGO tells you about the concentration of methylglyoxal.

UMF® tells you considerably more about the honey.

MGO is useful when considering potency, while UMF certification provides additional assurance around the identity, quality and authenticity of genuine New Zealand Manuka honey.

This distinction becomes particularly useful when comparing jars from different producers. A large number on the front of a jar may look impressive, but the quality and authentication system behind that number matters too.

What Do the Different UMF® Strengths Mean?

Manuka honey is available across a range of UMF grades. Choosing between them becomes easier when you consider how you intend to use the honey rather than simply looking for the highest number.

UMF® 5+

A good entry-level choice for people who want genuine UMF-certified New Zealand Manuka honey as part of their everyday diet.

It can be enjoyed from the spoon, added to food or used as a premium alternative to ordinary honey.

UMF® 10+

A popular step up for customers wanting a higher level of Manuka activity while retaining a honey suitable for regular everyday use.

For many households, UMF 10+ provides a useful balance between strength, versatility and price.

UMF® 15+

A higher-potency Manuka honey containing substantially more MGO than lower grades.

This grade is often chosen by customers specifically looking for a stronger premium Manuka honey rather than simply an everyday sweetener.

UMF® 20+ and Above

These are increasingly concentrated and comparatively scarce grades of Manuka honey.

Their higher potency and limited availability generally make them considerably more expensive, so they are normally purchased by people deliberately seeking a high-grade Manuka honey.

Does a Higher UMF® Rating Always Mean Better?

Not necessarily.

A higher UMF rating indicates a higher grade according to the UMF system, but that does not mean everyone needs the strongest honey available.

Think of it instead as choosing the appropriate grade for your intended use and budget.

If you simply enjoy Manuka honey regularly, paying a substantial premium for one of the highest grades may offer little practical advantage for your particular purpose. Someone deliberately seeking a higher-potency Manuka honey, however, may prefer UMF 15+, 20+ or above.

So rather than asking:

“What is the strongest Manuka honey?”

a better question is:

“What strength of genuine Manuka honey is appropriate for what I want it for?”

Why Does Manuka Honey Become More Expensive at Higher Grades?

Higher-grade Manuka honey is naturally less abundant.

Beekeepers cannot simply manufacture UMF 15+, 20+ or 25+ honey by deciding to produce a stronger batch. Its composition is influenced by the nectar collected by the bees, environmental conditions and the characteristics of the resulting honey.

After harvesting, batches are laboratory tested and graded. Only honey meeting the relevant certification requirements can carry the corresponding UMF grade.

As the grades increase, qualifying honey becomes scarcer. This scarcity, together with testing, certification and strong international demand, helps explain why prices can rise substantially at the higher grades.

Why Authenticity Matters When Buying Manuka Honey

Honey adulteration is not unique to Manuka honey. Honey generally can be vulnerable to adulteration, substitution or misrepresentation as it moves through international supply chains.

However, genuine New Zealand Manuka honey is comparatively scarce and commands a substantial premium over many conventional honeys. This combination of rarity, high value and international demand makes authenticity particularly important.

Honey adulteration can take different forms, including the addition of sugar syrups, blending with other honeys, or misrepresenting a honey's botanical or geographical origin. Authentication of premium honey has therefore become an important area of food science and quality control.

This does not mean that overseas-packed honey is necessarily adulterated. Rather, it demonstrates why traceability, independent testing and control of the supply chain are especially valuable when purchasing a premium product such as Manuka honey.

Why “Packed and Sealed in New Zealand” Matters

An important feature of UMF™ certification is that certified retail Manuka honey is packed and sealed for consumers in New Zealand.

This provides another layer of protection and traceability. Once valuable bulk honey leaves its country of origin, a longer and more complex supply chain can create additional opportunities for substitution, blending or other changes before the product reaches the consumer.

By requiring UMF-certified retail honey to be packed and sealed in New Zealand, the certification system helps maintain a traceable chain from the New Zealand producer through to the finished jar.

For consumers, this means UMF represents considerably more than a potency number. It provides additional assurance around origin, authenticity, testing, quality and traceability.

How Can I Tell Whether Manuka Honey Is Genuine?

When buying New Zealand Manuka honey, look beyond attractive packaging and large numbers on the label.

For UMF-certified honey, look for:

• the UMF™ quality mark and rating
• the producer's UMFHA licence number
• a batch number providing traceability
• clear New Zealand origin
• confirmation that the honey has been packed and sealed in New Zealand

These safeguards help consumers distinguish independently certified New Zealand Manuka honey from products relying primarily on marketing terminology or a single activity number.

New Zealand Government Authentication vs UMF® Certification

These two systems are related, but they are not the same thing.

New Zealand's Ministry for Primary Industries has established a scientific definition for Manuka honey intended for export. The testing uses four chemical markers and one DNA marker and includes criteria for distinguishing monofloral from multifloral Manuka honey.

UMF® certification adds a further independent quality-assurance system. It assesses important characteristics including MGO, leptosperin, DHA and HMF and incorporates requirements around quality, traceability and New Zealand packing and sealing.

So a product being described as New Zealand Manuka honey and a product carrying genuine UMF certification are not automatically the same thing.

Monofloral vs Multifloral Manuka Honey

You may also see Manuka honey described as monofloral or multifloral.

Monofloral Manuka honey predominantly reflects nectar from Manuka, whereas multifloral Manuka honey contains Manuka alongside nectar from other floral sources.

New Zealand's MPI authentication system has defined scientific criteria for distinguishing monofloral from multifloral Manuka honey.

Neither description should be confused with the UMF strength itself. They describe different characteristics of the honey.

So Which Manuka Honey Should I Choose?

For most people, the decision can be kept relatively simple.

• If you want an everyday Manuka honey, a lower UMF grade can be a practical starting point.
• If you want a stronger premium honey while retaining versatility for regular use, consider UMF 10+.
• If you are deliberately seeking a higher-potency Manuka honey, UMF 15+ or above may be more appropriate.

Regardless of strength, favour genuine New Zealand Manuka honey with clear certification and traceability.

The biggest number is not automatically the best purchase.

The best choice is the honey whose authenticity, quality, strength and price suit what you actually want it for.

Want to Explore the Science Behind Manuka Honey?

Manuka honey is considerably more complex than a single UMF or MGO number. Its chemistry, authenticity, biological activity and quality have been the subject of extensive scientific research.

For readers who want to explore the subject in greater depth, visit our Manuka Honey Research & Science articles, where we examine topics including:

• What Is Manuka Honey? Composition, Traditional Use, and Scientific Research
• UMF vs MGO: What's the Difference and How Do They Compare?
• Why Is Manuka Honey So Effective? The Science Behind Its Unique Activity
• our Manuka Honey & Modern Research series

Those articles explore the research in greater depth, while this guide is designed to help you turn that information into a practical and informed purchasing decision.

This article is provided for general educational purposes and is not intended as medical advice. Honey should not be given to children under 12 months of age.