MGO Manuka Honey UK Explained: What the Numbers Actually Mean

Manuka honey from New Zealand has become one of the most sought-after premium foods and natural products in the UK. But walk into any health shop or browse online and you'll encounter a bewildering range of ratings — MGO 400, MGO 800, MGO 1000+, UMF 15, UMF 20. What do these numbers actually mean, and how do you choose the right one? This guide explains everything clearly.

What Does MGO Stand For?

MGO stands for methylglyoxal — the naturally occurring compound found in manuka honey that is responsible for its distinctive properties. Methylglyoxal is present in most honeys at very low levels, but it occurs in genuinely significant concentrations only in honey produced from the nectar of the Leptospermum scoparium plant, commonly known as the mānuka bush, which grows in New Zealand and parts of Australia.

The MGO number on a jar of manuka honey tells you the concentration of methylglyoxal in that honey, measured in milligrams per kilogram (mg/kg). A jar labelled MGO 400 contains at least 400mg of methylglyoxal per kilogram of honey. MGO 1000 contains at least 1000mg/kg.

Higher MGO = higher methylglyoxal concentration. It's a straightforward linear scale.

How MGO Levels Are Tested and Verified

MGO content in manuka honey is tested by independent laboratories using high-performance liquid chromatography (HPLC) — a highly accurate analytical method that can precisely quantify methylglyoxal concentration. Reputable manuka honey producers test every batch independently and display the MGO rating prominently on the label.

In New Zealand, the government body MPI (Ministry for Primary Industries) introduced legally binding standards for manuka honey in 2018, requiring both DNA testing of pollen and chemical marker testing to verify authentic manuka origin. These regulations protect buyers from adulterated or mislabelled products sold as manuka honey.

When buying in the UK, look for:

• A stated MGO rating with a minimum guarantee (not an average)
• New Zealand origin clearly stated
• An independent lab test certificate or batch number you can verify

MGO 400 vs MGO 800 vs MGO 1000: What's the Difference?

The MGO scale gives you a direct comparison of methylglyoxal concentration:

• MGO 100–300 — Entry-level manuka honey. A step above standard honey but relatively low methylglyoxal content. Often used as a daily food product rather than a premium wellness product.
• MGO 400 — Mid-range and widely popular in the UK. A meaningful concentration of methylglyoxal while remaining affordable relative to higher grades. A good everyday choice for those who want genuine manuka quality.
• MGO 800 — Premium grade. Significantly higher methylglyoxal concentration. Often chosen by those who specifically seek out high-potency manuka honey.
• MGO 1000+ — Ultra-premium. High-potency manuka honey with a very high methylglyoxal concentration. These products are typically significantly more expensive, reflecting the rarity of honey at this potency level and the extensive testing required to verify it.

Higher isn't automatically "better" for every use — it depends on what you're looking for. As a food or daily wellness addition, MGO 400 is an excellent choice. Those seeking the highest available potency typically opt for MGO 800 or above.

UMF vs MGO: Two Rating Systems Explained

Alongside the MGO rating, you'll also encounter the UMF (Unique Mānuka Factor) rating system. Both systems measure the potency of manuka honey, but they work differently.

• MGO measures only the methylglyoxal content in mg/kg. It's a single-compound measurement that is straightforward and transparent.
• UMF is a more comprehensive grading system administered by the UMF Honey Association (UMFHA) in New Zealand. It measures multiple chemical markers — including methylglyoxal (MGO), leptosperin (a compound unique to genuine mānuka nectar), and DHA (dihydroxyacetone) — to verify both potency and authenticity.

The approximate conversion between UMF and MGO is:

• UMF 5 ≈ MGO 83
• UMF 10 ≈ MGO 263
• UMF 15 ≈ MGO 514
• UMF 20 ≈ MGO 829
• UMF 25 ≈ MGO 1200+

Both systems are legitimate. UMF provides broader authenticity verification; MGO provides clear, simple potency information. Many quality manuka honey products display both ratings.

Raw vs Pasteurised Manuka Honey

Manuka honey is sometimes pasteurised — heated to a temperature that kills any microorganisms and extends shelf life. The question for buyers is whether pasteurisation affects MGO content.

The good news is that methylglyoxal is relatively heat-stable compared to many honey compounds. Research indicates that MGO levels are not significantly reduced by standard pasteurisation temperatures. However, pasteurisation does affect other compounds in honey — including natural enzymes, pollen, and some aromatic compounds.

Raw manuka honey is unheated and unfiltered, preserving the full natural compound profile of the honey as it came from the hive. Many premium producers offer raw manuka honey for this reason. Raw honey may crystallise more quickly than pasteurised honey, but this is natural and doesn't affect quality.

New Zealand Origin and the Mānuka Plant

Genuine manuka honey comes from bees that forage exclusively or predominantly on Leptospermum scoparium — the mānuka bush — which is native to New Zealand. The plant produces nectar that bees convert into honey with uniquely high methylglyoxal levels, owing to the high concentration of DHA (dihydroxyacetone) in the nectar, which converts to MGO during the honey's natural maturation.

New Zealand's government now legally defines and tests for genuine manuka honey before export, ensuring that products carrying the manuka designation have been independently verified. Always check that the honey on your shelf states New Zealand origin.

Our manuka honey UK range is sourced directly from New Zealand, tested to confirm MGO content, and clearly labelled with the grade and origin.

How to Store Manuka Honey

Manuka honey is naturally shelf-stable due to its low moisture content and naturally acidic pH. Here are the key storage guidelines:

• Room temperature — Store in a cool, dry cupboard away from direct sunlight. There is no need to refrigerate.
• Keep sealed — Honey is hygroscopic (it absorbs moisture from the air). Always replace the lid tightly after use.
• Don't use wet spoons — Introducing water into the jar encourages fermentation. Use a clean, dry spoon every time.
• Crystallisation is normal — Raw or lightly processed manuka honey may crystallise over time. This is a sign of natural, minimally processed honey. Gentle warming (not microwaving) will restore it to a liquid state without significantly affecting MGO content.

Frequently Asked Questions

What MGO level should I choose as a first-time buyer?

MGO 400 is the most popular choice for first-time buyers and makes an excellent starting point. It offers a meaningful methylglyoxal concentration at a price point that won't put you off buying it regularly. Once you've established a routine and want higher potency, you can step up to MGO 800 or above.

Is higher MGO manuka honey always better?

Higher MGO means higher methylglyoxal concentration, but whether that translates to being "better" depends on how you're using the honey. For most people enjoying manuka honey as part of their daily wellness routine, MGO 400–800 is an excellent range. Very high MGO (1000+) is sought by those who specifically want the most potent product available.

Can I cook with manuka honey?

You can use manuka honey in cooking, but high heat will significantly reduce methylglyoxal content. To preserve the MGO content, use manuka honey in ways that don't involve cooking — stirred into warm (not boiling) drinks, spread on toast that has cooled slightly, or eaten directly from the spoon. The distinctive flavour also works well in dressings and marinades applied after cooking.

Ready to try it? Shop our premium Manuka honey — authentic MGO-rated, and shipped free across the UK.