Manuka Honey and Bacteria: What the Research Shows About Its Antibacterial Power, Wound Healing, and Limits

Headlines about a “mysterious honey” that kills every bacterium scientists test it against have circulated for years. The honey in question is manuka, produced in New Zealand and Australia by bees foraging on the flowers of the manuka bush, Leptospermum scoparium. It commands prices many times higher than ordinary honey and is sold both as food and as a medical wound dressing.

Manuka honey does have genuinely unusual antibacterial properties, and medical-grade honey is used in wound care. But “kills all bacteria” overstates what the research shows, and many claims about eating manuka honey to treat infections go well beyond the evidence. This article explains what makes manuka different, what laboratory and clinical studies have found, how to read manuka labels, and when honey should not be used.

Why Honey Fights Bacteria

Honey’s ability to inhibit microbes has been known since ancient times, when it was used to dress wounds in Egypt, Greece, and elsewhere. Modern research has identified several reasons:

High sugar concentration. Honey is roughly four-fifths sugar and very low in available water. This draws water out of bacterial cells through osmosis and prevents most microbes from growing.

Acidity. Honey is acidic, with a pH typically between about 3.2 and 4.5, which is unfavorable for many bacteria.

Hydrogen peroxide. Bees add an enzyme, glucose oxidase, to nectar. When honey is diluted, for example by wound fluid, this enzyme produces small amounts of hydrogen peroxide, which has antibacterial effects. This activity can be reduced by heat, light, and an enzyme called catalase present in body tissues.

Plant-derived compounds. Depending on the flowers bees visit, honey contains various phenolic compounds and other substances with antimicrobial properties.

What Makes Manuka Different

For years, researchers noticed that manuka honey retained strong antibacterial activity even when its hydrogen peroxide activity was blocked, a property described as “non-peroxide activity.” In 2008, a study by Elvira Mavric and colleagues at the Technical University of Dresden, published in Molecular Nutrition & Food Research, identified methylglyoxal (MGO) as the dominant antibacterial constituent of manuka honey. Manuka contained far higher levels of MGO than other honeys tested.

MGO forms in manuka honey from another compound, dihydroxyacetone (DHA), which is present in high amounts in manuka flower nectar. The conversion continues during storage, so MGO levels in manuka honey can rise over time. Because MGO activity does not depend on hydrogen peroxide, it is more stable and is not neutralized by catalase in wounds, which helps explain manuka’s reputation in wound care.

Does Manuka Really Kill “All” Bacteria?

Laboratory studies have found manuka honey inhibits a broad range of bacteria, including Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, and many others, at concentrations achievable in wound dressings. Some studies have found it can disrupt biofilms, the protective communities bacteria form on surfaces and in chronic wounds.

One of the most frequently cited findings concerns resistance. A 2010 study by Rose Cooper and colleagues in the European Journal of Clinical Microbiology & Infectious Diseases repeatedly exposed several bacterial species to sublethal concentrations of medical-grade manuka honey and found no stable resistance developed, in contrast to the antibiotic rifampicin, to which resistance emerged. The researchers suggested that honey’s multiple mechanisms of action make resistance difficult to develop.

These findings are striking, but they do not mean manuka kills all bacteria in every situation. Effectiveness depends on concentration; diluted honey is much less potent, and the amount reaching bacteria inside the body after eating honey is very different from honey applied directly to a wound. Different bacterial species and strains vary in susceptibility. Laboratory dishes do not reproduce the complexity of human infections. And “no resistance in the lab” is not a guarantee that resistance could never emerge with widespread use. The phrase “kills all bacteria scientists throw at it” is a headline simplification of real but more limited findings.

Honey in Wound Care

The strongest clinical use of honey is in wound care, using sterilized, medical-grade products rather than food honey. Medical-grade honey dressings, many based on manuka, have been cleared by regulators in the United States, Europe, and elsewhere for managing wounds and burns. They are sterilized, typically by gamma irradiation, to remove bacterial spores that can be present in raw honey.

A 2015 Cochrane systematic review by Andrew Jull and colleagues analyzed 26 randomized trials involving 3,011 participants, covering burns, chronic wounds such as leg ulcers, surgical wounds, and other injuries. It found that honey appears to heal partial-thickness burns more quickly than conventional dressings, and that burns treated with honey may heal more quickly than those treated with silver sulfadiazine in some comparisons, while early surgical excision and grafting healed burns faster than honey. For most other wound types, the evidence was of low quality or insufficient to draw conclusions, largely because of small trials and risk of bias.

In practice, honey dressings are one option among many in wound care. They may be particularly useful for certain burns and infected or sloughy wounds, but decisions about wound treatment should involve a clinician, especially for deep, large, or non-healing wounds, or for people with diabetes or poor circulation.

Honey for Coughs

Honey has also been studied as a remedy for cough. A 2018 Cochrane review by Olabisi Oduwole and colleagues examined honey for acute cough in children aged 12 months to 18 years. It concluded with moderate certainty that honey probably reduces cough frequency better than no treatment or placebo, and that it may perform similarly to some over-the-counter cough medicines. Most studies used ordinary honey, not specifically manuka, so the benefit appears to be a general property of honey.

Honey is a reasonable home remedy for cough in children over one year old and in adults, particularly because many over-the-counter cough medicines are not recommended for young children. It is not a treatment for underlying infections, and children with difficulty breathing, high fever, or persistent cough need medical evaluation.

Eating Manuka Honey: What Is and Isn’t Supported

Much manuka honey is sold as a premium food or “wellness” product with claims about immunity, digestive health, sore throats, and stomach ulcers. Laboratory studies have tested manuka against Helicobacter pylori, the bacterium that causes many stomach ulcers, but clinical studies in people have not shown that eating manuka eradicates the infection, which requires antibiotic-based treatment. There is little clinical evidence that eating manuka honey prevents or treats infections elsewhere in the body, since MGO and other compounds are diluted and metabolized after ingestion.

As a food, manuka honey is a sweetener with a distinctive flavor. Its sugar content is similar to other honeys, so people managing blood sugar should count it like other sugars. Enjoying it as a food is fine; paying a premium expecting medical benefits from eating it is not supported by strong evidence.

Reading Manuka Labels: UMF, MGO, and Authenticity

Manuka honey is graded by its antibacterial activity or chemical markers. The two most common systems are MGO ratings, which state the methylglyoxal content in milligrams per kilogram, and UMF (Unique Manuka Factor), a trademarked grading system that considers MGO along with other markers of authenticity and freshness. Higher numbers indicate higher antibacterial activity and higher prices.

Because manuka is so valuable, it has been a target of fraud and mislabeling, with more honey labeled manuka sold worldwide at times than could plausibly be produced. To address this, New Zealand’s Ministry for Primary Industries established a scientific definition of manuka honey using a combination of chemical markers and a DNA marker from manuka pollen, which honey exported from New Zealand as manuka must meet. Honey fraud more broadly is discussed in our guide to food fraud and how it is detected.

Why Manuka Is Scarce and Expensive

Manuka honey’s price reflects its limited supply. The manuka bush flowers for only a few weeks each year, and weather during that short window strongly affects how much nectar bees can collect. Many manuka stands grow in remote, rugged areas, and some producers use helicopters to place and retrieve hives. Only honey that meets testing criteria can be sold as manuka, and higher-activity grades represent a smaller fraction of the harvest. Combined with strong international demand, these factors keep prices high and create incentives for fraud.

Honey and Antibiotics: Complement, Not Replacement

Interest in honey has grown alongside concern about antibiotic resistance, and some headlines suggest manuka could replace antibiotics. That framing is misleading. Topical honey can be useful for certain wounds and burns, where it is applied directly at high concentration. Antibiotics remain essential for treating serious bacterial infections inside the body, such as pneumonia, kidney infections, or bloodstream infections, which honey cannot reach in effective concentrations.

Researchers are exploring whether honey and its components could be combined with antibiotics to improve effectiveness, particularly against biofilms in chronic wounds. Some laboratory studies have found that manuka honey can make certain bacteria more susceptible to antibiotics. These findings are promising but preliminary, and any such use would need confirmation in clinical trials.

Other Honeys Studied for Medical Use

Manuka is the best-known medicinal honey, but it is not the only one studied. Researchers have examined honeys from various floral sources around the world, several of which show antibacterial activity, often mainly through hydrogen peroxide rather than MGO. In the Netherlands, a medical-grade honey produced under controlled conditions has been developed and studied for its antibacterial properties. Honeys from Malaysia, Chile, and other regions have also been investigated. The common lesson is that antibacterial strength varies widely between honeys and even between batches, which is why medical use relies on standardized, tested, sterilized products rather than ordinary honey.

Storage and Shelf Life

Properly sealed honey keeps for a very long time because its high sugar content and low water activity prevent microbial growth. Crystallization, in which honey becomes thick and grainy, is natural and does not mean it has spoiled; gently warming the jar in warm water can reliquefy it. For manuka specifically, MGO levels tend to increase during storage as DHA converts to MGO, though other quality markers may change over time. Store honey at room temperature, away from direct sunlight and heat, with the lid tightly closed to prevent moisture absorption, which could allow fermentation.

Key Terms

Methylglyoxal (MGO): The compound mainly responsible for manuka honey’s non-peroxide antibacterial activity.

Dihydroxyacetone (DHA): A compound in manuka nectar that converts to MGO in honey.

UMF: Unique Manuka Factor, a trademarked grading system for manuka honey.

Non-peroxide activity: Antibacterial activity remaining after hydrogen peroxide effects are removed.

Medical-grade honey: Sterilized, standardized honey produced for wound care.

Biofilm: A protective community of bacteria attached to a surface, common in chronic wounds and harder to treat.

A Brief History of Honey in Medicine

Honey is among the oldest recorded medicines. Ancient Egyptian medical papyri described honey-based wound dressings, and Greek physicians, including Hippocrates, recommended honey for wounds and ulcers. Honey remained part of wound care in many cultures for centuries. With the arrival of antibiotics in the mid-20th century, its medical use largely faded in Western medicine.

Interest revived in the late 20th century, driven partly by rising antibiotic resistance and partly by research, much of it at the University of Waikato in New Zealand, documenting manuka’s unusual antibacterial activity. Regulatory clearance of sterilized medical honey dressings followed in the 2000s, bringing honey back into modern wound clinics as a standardized product rather than a folk remedy.

Manuka Beyond New Zealand

Manuka honey is most closely associated with New Zealand, but Leptospermum species also grow in Australia, where bees produce honeys that can contain high levels of MGO as well. Producers in the two countries have long disputed who may use the word “manuka,” including through trademark proceedings in several markets. For consumers, the more important questions are whether a product is independently tested for its stated MGO or activity level and whether its origin is clearly identified.

Safety: Who Should Avoid Honey

Infants under 12 months. Honey can contain spores of Clostridium botulinum, which can grow in an infant’s immature gut and cause infant botulism, a serious paralytic illness. Health authorities advise that no honey of any kind, including manuka, raw, or pasteurized honey, be given to babies under one year. Medical-grade honey for wounds is sterilized and used under clinical supervision, which is different from eating honey.

People with diabetes. Honey is mostly sugar and raises blood glucose like other sugars. It can be part of a diabetes eating plan in controlled amounts but should not be viewed as a health food that offsets its sugar content.

People with allergies. People allergic to bee products or certain pollens can react to honey. Topical honey can occasionally cause stinging or irritation in wounds.

Wound care at home. Do not put supermarket or raw honey on open wounds; it is not sterile and may contain spores and other contaminants. Use only products labeled and sold for wound care, and seek medical advice for serious, deep, infected, or slow-healing wounds.

How to Choose Manuka Honey

Decide what you want it for. For eating, a lower grade offers manuka’s flavor at a lower price; higher grades add cost without proven benefit when eaten. For wounds, use medical-grade dressings, not jars from a grocery store.

Look for a stated MGO or UMF value and evidence of independent testing.

Check origin and certification. Honey exported from New Zealand as manuka must meet the government’s scientific definition. Clear labeling of country and producer is a good sign.

Be skeptical of health claims. Labels or ads promising cures for infections, ulcers, or immune problems overstate the evidence.

Watch the price. Very cheap high-grade manuka is a warning sign of possible fraud.

Myths About Manuka Honey

“Manuka kills all bacteria.” It inhibits many bacteria in laboratory conditions at sufficient concentrations, but not all bacteria under all conditions.

“Eating manuka works like an antibiotic.” There is little clinical evidence that eating manuka treats infections in the body.

“Bacteria can never become resistant to manuka.” Laboratory studies did not find resistance developing, which is encouraging, but that does not guarantee it could never happen.

“Any honey can be used on wounds.” Only sterilized medical-grade honey should be used on wounds.

“Higher UMF is always better.” Higher grades have more antibacterial activity, which matters for medical products, but there is no evidence higher grades provide more benefit when eaten.

Where Research Is Heading

With antibiotic resistance a growing global threat, researchers continue to study honey-based and MGO-based treatments, including combinations of honey with antibiotics, honey-impregnated dressings and gels, and treatments for biofilm-associated infections such as chronic wounds and some sinus infections. Larger, well-designed clinical trials are needed to establish where honey offers clear advantages over existing treatments. For now, its best-supported uses remain certain burns and wounds, under medical guidance, and cough relief in children over one year.

How Medical Honey Is Used in Wound Care

In clinical settings, medical-grade honey comes in several forms: tubes of gel or paste, honey-impregnated dressings, and alginate or hydrocolloid dressings containing honey. A clinician typically cleans the wound, applies the honey product directly or as a dressing, and covers it with a secondary dressing. Honey draws fluid from the wound, which can help remove dead tissue and reduce odor, so dressings may need changing frequently at first. Some patients feel a temporary stinging sensation.

Honey dressings are not suitable for every wound. Deep wounds, wounds with exposed bone or tendon, heavily infected wounds with spreading redness or fever, and wounds in people with poorly controlled diabetes or poor circulation need medical assessment, and many require other treatments, including antibiotics or surgery.

Choosing Honey for a Cough

Because the evidence for cough relief comes mostly from ordinary honeys, there is no need to buy expensive manuka for this purpose. Typical approaches used in studies give children over one year about a teaspoon of honey before bedtime, either on its own or mixed into a warm drink. Adults can do the same. Darker honeys such as buckwheat honey have been used in some trials. Honey should still never be given to infants under 12 months.

What Studies Still Need to Answer

Despite growing interest, important questions remain. Larger, high-quality trials comparing honey dressings with modern wound dressings for specific wound types would clarify where honey offers real advantages. Studies of combined honey and antibiotic treatments in people are needed to see whether laboratory synergies translate into clinical benefit. Research on how honey affects biofilms in real wounds, and on the cost-effectiveness of honey products, would help healthcare systems decide when to use them. For oral use, well-designed trials would be needed before claims about digestive or immune benefits could be supported.

Common Questions About Buying Manuka

Is raw or creamed manuka better? Texture differences reflect processing and crystallization, not antibacterial strength. Check the stated MGO or UMF value instead.

Does heating destroy manuka’s benefits? MGO is relatively heat-stable, but heating can affect other compounds and the hydrogen peroxide activity found in many honeys. For flavor and quality, avoid high heat.

Is multifloral manuka the same as monofloral? Under New Zealand’s definition, monofloral manuka contains a higher proportion of manuka-derived markers than multifloral manuka, which contains manuka blended with other floral sources. Monofloral generally costs more.

Is Australian manuka legitimate? Australian honeys from Leptospermum species can contain high MGO levels. Look for clear labeling of origin, species, and independent testing.

Is Manuka Worth the Price?

Whether manuka honey is worth its premium depends on what you want from it. For wound care, medical-grade manuka products have a clear role under clinical guidance, and their cost is part of standard wound-care budgets. For cough relief, ordinary honey appears to work, so paying extra for manuka is unnecessary. For eating, manuka offers a distinctive earthy, slightly bitter flavor that some people enjoy, but there is little evidence that eating it provides health benefits beyond those of other honeys.

Shoppers who choose manuka for its taste or origin can save money by buying lower-grade products, since higher MGO or UMF numbers mainly matter for antibacterial activity. Those buying it for health reasons should be realistic about what the research shows and cautious about marketing claims.

Honey and Oral Health

Because manuka inhibits bacteria in laboratory studies, some researchers have explored its effects on bacteria involved in dental plaque and gum disease. Small studies have reported reductions in plaque or gum inflammation with manuka-containing products, but the evidence is preliminary. Honey is still a sugar, and frequent exposure of teeth to sugars contributes to tooth decay. Regular brushing with fluoride toothpaste, flossing, and dental checkups remain the foundation of oral health.

Honey and Children

For children over one year old, honey is a safe and inexpensive option for soothing coughs, and studies suggest it may help them sleep better during a cold. Because honey sticks to teeth, brushing afterward is a good habit, especially at bedtime. Children with severe symptoms, such as difficulty breathing, high or persistent fever, or signs of dehydration, need medical evaluation rather than home remedies. And the most important rule bears repeating: babies under 12 months should never be given honey in any form.

Honey for Sore Throats in Adults

Adults often use honey in warm tea or water to soothe a sore throat. Its thick texture coats the throat and can temporarily ease irritation, and the cough research suggests a modest benefit for related symptoms. Sore throats caused by viral infections usually improve within a week. A sore throat that is severe, lasts longer than a week, comes with difficulty swallowing or breathing, a high fever, or swollen glands may need medical evaluation, since bacterial infections such as strep throat require antibiotics.

The Bottom Line

Manuka honey is genuinely unusual. Its high methylglyoxal content gives it strong, stable antibacterial activity in laboratory studies, including against antibiotic-resistant bacteria, and bacteria did not develop resistance to it in experiments. Medical-grade honey dressings have a recognized role in treating certain burns and wounds, and ordinary honey can help soothe children’s coughs. But manuka does not kill all bacteria in every setting, eating it is not a substitute for antibiotics, and many health claims made for manuka as a food are not supported by clinical evidence. Choose products wisely, use medical honey for wounds under guidance, and never give honey to infants under one year.

Frequently Asked Questions

Does manuka honey kill all bacteria?

No. In laboratory studies it inhibits a wide range of bacteria, including antibiotic-resistant strains, at sufficient concentrations, but its effectiveness depends on concentration, species, and setting.

What makes manuka honey special?

Its high methylglyoxal content, derived from compounds in manuka flower nectar, provides stable antibacterial activity in addition to the properties all honey shares.

Can I put manuka honey on a cut?

Use only sterilized medical-grade honey products designed for wounds. Food honey is not sterile. See a clinician for serious or slow-healing wounds.

Does honey help a cough?

A Cochrane review found honey probably reduces cough symptoms in children over one year better than no treatment or placebo. Any honey appears to work; manuka is not required.

Can babies have manuka honey?

No. No honey of any kind should be given to infants under 12 months because of the risk of infant botulism.

What do UMF and MGO numbers mean?

They indicate manuka honey’s antibacterial strength and authenticity markers. MGO states methylglyoxal content; UMF is a grading system that includes MGO and other markers.

References

1. Mavric E, Wittmann S, Barth G, Henle T. Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand. Molecular Nutrition & Food Research. 2008;52(4):483–489. PMID 18210383
2. Cooper RA, Jenkins L, Henriques AF, et al. Absence of bacterial resistance to medical-grade manuka honey. European Journal of Clinical Microbiology & Infectious Diseases. 2010;29(10):1237–1241. PMID 20549529
3. Jull AB, Cullum N, Dumville JC, et al. Honey as a topical treatment for wounds. Cochrane Database of Systematic Reviews. 2015;(3):CD005083. PMID 25742878
4. Oduwole O, Udoh EE, Oyo-Ita A, Meremikwu MM. Honey for acute cough in children. Cochrane Database of Systematic Reviews. 2018;4:CD007094. PMID 29633783
5. New Zealand Ministry for Primary Industries. Mānuka honey. mpi.govt.nz

Last updated: October 1, 2026