A good MGO for manuka honey depends on what you plan to use it for, but for most people seeking health benefits beyond just a sweetener, MGO 250+ is the sweet spot. That level provides meaningful antibacterial activity without the steep price tag of premium grades. Below MGO 100, you’re mostly getting a nice-tasting honey. Above MGO 500, you’re paying a significant premium for strength that only matters in specific situations.
What MGO Actually Measures
MGO stands for methylglyoxal, the compound responsible for manuka honey’s antibacterial properties. The number on the jar tells you how many milligrams of methylglyoxal are present per kilogram of honey. An MGO 250+ jar contains at least 250 mg/kg, while an MGO 550+ jar contains at least 550 mg/kg. Higher numbers mean stronger antibacterial activity, but they also mean a sharper, more medicinal taste and a higher price.
Not all honey labeled “manuka” is the real thing. New Zealand’s Ministry for Primary Industries requires exported manuka honey to pass tests for four specific chemicals from manuka nectar plus a DNA marker from manuka pollen. These tests exist because the global demand for manuka honey far exceeds what New Zealand actually produces, making fraud common. Look for jars that reference MPI certification or come from brands with verifiable New Zealand origins.
MGO Levels and What They’re Good For
Here’s how the different tiers break down in practical terms:
- MGO 30 to 100 (low strength): Works fine as a daily sweetener or a first introduction to manuka honey. You’ll get some of the natural enzymes present in all raw honey, but the antibacterial punch is minimal. This range is equivalent to roughly UMF 5+ or 6+.
- MGO 250+ (medium strength): The entry point for genuine therapeutic use. Equivalent to UMF 10+, this level delivers measurable antibacterial activity and is a popular choice for general immune support and daily wellness. It hits a good balance of potency and affordability.
- MGO 400 to 550 (high strength): Equivalent to UMF 13+ through UMF 16+. Often chosen for topical skin applications, sore throats, and extra support during cold and flu season. The flavor becomes noticeably more bitter at this range.
- MGO 700+ (very high strength): Equivalent to UMF 18+ and above. Premium-grade honey used for targeted purposes. The price jumps considerably here, sometimes two to three times the cost of MGO 250+.
The Antibacterial Threshold
Lab research on manuka honey’s germ-fighting ability reveals something that may surprise you: even lower-grade manuka honey shows significant antibacterial effects. In a study testing manuka honey against drug-resistant bacteria including MRSA, UMF 5+ honey (roughly MGO 83+) actually required a lower concentration to inhibit bacterial growth than UMF 15+ honey against staph bacteria. All three grades tested, UMF 5+, 10+, and 15+, were effective against a broad spectrum of organisms, including multi-drug-resistant strains. The honey was more potent overall against staph-type bacteria than against gut-type bacteria.
This doesn’t mean lower MGO is “better” than higher MGO. The antibacterial mechanism involves more than just methylglyoxal concentration. Other naturally occurring compounds in the honey, including hydrogen peroxide production and acidity, contribute to its effects. But it does mean you don’t necessarily need the most expensive jar on the shelf to get real antibacterial benefit.
Oral Health Benefits Start at MGO 500+
One well-studied use for manuka honey is dental health. A pilot study using manuka honey rated UMF 15+ (approximately MGO 514+) found that participants who used it as a chewable product saw their plaque scores drop from 0.99 to 0.65, and bleeding gum sites dropped from 48% to 17%. The control group showed no significant changes. If oral health is your primary goal, aim for MGO 500+ or higher, which corresponds to UMF 15+.
MGO vs. UMF: Two Labels, One Idea
You’ll see two main rating systems on manuka honey jars. MGO measures the methylglyoxal content directly. UMF (Unique Manuka Factor) is a broader grading system that accounts for methylglyoxal along with other markers. Both are legitimate, and here’s how they roughly convert:
- MGO 83+ = UMF 5+
- MGO 263+ = UMF 10+
- MGO 400+ = UMF 13+
- MGO 514+ = UMF 15+
- MGO 700+ = UMF 18+
If a jar carries only an MGO rating with no UMF certification, that’s not automatically a red flag. MGO is a straightforward lab measurement. But UMF certification does add an extra layer of third-party verification that the honey is genuine monofloral manuka. When in doubt, a jar with both ratings gives you the most confidence.
How to Choose Based on Your Needs
If you’re stirring honey into tea or drizzling it on toast and just want something healthier than regular honey, MGO 100+ is perfectly fine and won’t break the bank. You’ll get a pleasant flavor with mild wellness benefits.
For daily immune support, seasonal wellness, or general use as a functional food, MGO 250+ to 400+ is the range most people should target. This is where you get clear antibacterial activity at a price that’s reasonable for regular use. A teaspoon a day in this range is a common routine.
If you’re using manuka honey topically on minor cuts, for sore throats, or for gum health, step up to MGO 500+ or above. The higher concentration matters more in these direct-contact applications. Some people keep a lower-grade jar for the kitchen and a higher-grade jar for targeted use.
One Caution for People With Diabetes
Manuka honey is still honey, meaning it’s roughly 80% sugar and will affect blood glucose. But there’s an additional concern for people with diabetes beyond the sugar content. The methylglyoxal in manuka honey is the same compound that accumulates naturally in the blood of people with diabetes, where it can impair wound healing and damage cells. Researchers have raised specific concerns that applying high-MGO manuka honey to diabetic ulcers could worsen healing rather than help it. If you have diabetes and are considering manuka honey for wound care, that’s a conversation worth having with your care team before spending on a premium jar.