Several months ago, a man had to be rushed to the hospital after eating some wild honey brought back from the hills of Nepal.
Within about 30 minutes, his heart rate had dropped dangerously low and his blood pressure had collapsed. He recovered, but the episode was terrifying for the whole family.
It turns out, that wild honey was actually wild honey, known locally in Nepal as ‘bhir mauri ko maha,’ from the Himalayan cliff bee.
These bees forage on rhododendron flowers that carry a natural toxin called grayanotoxin. As bees collect the nectar, the toxin ends up concentrated in the honey.
This is what’s now popularized worldwide as ‘mad honey.’
Eat a teaspoonful and you might feel pleasantly warm and slightly light-headed. Eat more than a few tablespoons and your heart rate can drop to life-threatening levels.
The exact amount that causes harm varies by batch, season and location.
The indigenous Gurung people of Nepal have built up knowledge of safe doses over generations, but that knowledge is being lost as wild Himalayan honey has begun to be sold on major international online platforms.
Eat a teaspoonful of wild honey and you might feel pleasantly warm and slightly light-headed; eat more and your heart rate can drop to life-threatening levels (stock image)
A honey hunter of the Gurung ethnic community harvests honeycomb at a cliff in the Lamjung district of Nepal
Sellers online market mad honey as a psychoactive superfood, and it often goes for several hundred US dollars per kilogram. Pictured above, a honey hunter harvests honeycomb in Nepal
Getting the full picture
For decades, experts have studied how insects and plants fight each other using chemistry.
Plants make toxic compounds, insects figure out ways to store or use those toxins, and the whole arms race plays out over millions of years. This fascinating world of insects and plants usually stays far from human lives.
But this mad honey is bringing toxic compounds into contact with humans, creating a public health problem.
Links in the chain
The Himalayan cliff bee, Apis laboriosa, is the world’s largest honeybee. It lives only in the high Himalayas, nesting and building enormous exposed combs on sheer cliff faces at altitudes of up to 13,000 feet (4,000 meters).
In the spring, when rhododendron flowers peak, the bees forage heavily on their blooms. The nectar contains grayanotoxin, a chemical the plant likely evolved to deter insects that steal nectar without pollinating the flower.
The bees collect the nectar anyway and concentrate it in their honey.
Scientists do not know how the bees tolerate a compound that can floor a human in a tablespoon, but they appear unaffected. For insects feeding on toxic plants, such tolerance rarely comes without a cost, though for Apis laboriosa, we do not yet know what that may be.
The Gurung people of Nepal’s Gandaki Province have harvested this honey safely for centuries. Wild honey hunting is a sacred tradition for them, embedded in ritual and passed down through generations.
What mad honey does to the human body
When a human eats more than about a teaspoon of this honey, the toxin interferes with how the heart muscle generates its electrical signals. This causes the heart rate to slow to dangerously low levels, leading the blood pressure to crash.
Without immediate treatment, the situation can become life-threatening. Most patients feel dizzy, nauseated and weak within 30 to 60 minutes.
Honey hunters climb rope to harvest wild honey from cliffs of mountain rock in Nepal
Wild honey comes from the Himalayan cliff bee, the Apis laboriosa, which is the world’s largest honeybee. It lives only in the high Himalayas, nesting and building enormous exposed combs on sheer cliff faces at altitudes of up to 13,000 feet
Fortunately, there have been no reported deaths in Nepal from eating this honey. Doctors treat patients with intravenous fluids and a drug called atropine, which restores a normal heart rhythm. Most recover within a day or two.
A team of researchers looked at records from 1976 to 2026 and found and reviewed 27 published papers documenting the cases of 68 patients from 2009 onward. These papers painted a surprisingly consistent picture.
About 72 percent of patients are middle-aged men, and it turns out that most of them ate the honey deliberately, not accidentally.
They were using it as a home remedy for high blood pressure or to improve sexual function, traditions that go back generations in Himalayan communities.
There is actually some experimental support for the blood pressure effect, with studies in rat models showing that small amounts do lower blood pressure.
The problem is that the gap between a medicinal dose and a toxic dose is very small and varies from one batch to the next.
The analysis also found that the harvest seasons and hospital admissions follow the same calendar. Poisonings cluster sharply in spring, when rhododendron flowers are at full bloom and the main honey harvest takes place. Spring honey carries the highest toxin concentrations of the year.
A smaller wave of cases appears in autumn during the secondary harvest. One case in our review involved two patients in Nepal who arrived at the same hospital on the same day in late October, both having eaten honey from the same batch.
A local problem going global
Sellers online market mad honey as a psychoactive superfood, and it often goes for several hundred US dollars per kilogram. But they do not always include warnings about how to consume the honey in safe amounts. And, of course, even if such a warning is included, consumers may not take it seriously.
Buyers in the United States, Europe and Asia are purchasing mad honey with no understanding of how little it takes to cause a serious cardiac incident that can put them in the hospital.
Cases of poisoning are already appearing. Fifteen poisoning cases from Nepalese honey were documented in South Korea as early as 2013. More recently, cases have also been confirmed in France and Qatar.
Doctors in these countries rarely encounter mad honey poisoning, and patients do not always think to mention what they ate. That combination delays diagnosis and slows treatment.
There has been at least one documented case of mad honey poisoning in the US.
The Utah Poison Control Center published a case in March 2025 involving a 50-year-old woman who consumed mad honey obtained from India to treat gastrointestinal symptoms she was experiencing.
She developed chest pain, lightheadedness, hallucinations and low blood pressure, with an abnormally low heart rate in the 50s. She was admitted to the hospital and given medications and fluids to treat her cardiovascular symptoms and discharged the following day.
Pictured above is Nepali ‘mad honey’
More to learn
Documenting who is getting poisoned and where is only the first step.
Now, researchers plan to test honey samples from different districts and seasons across Nepal to measure how much grayanotoxin is present and which specific grayanotoxin types dominate.
The researchers also plan to analyze the flowers themselves, testing different rhododendron species to understand which ones produce the most toxin and in what combinations.
And one fundamental question fascinates above all: What exactly happens inside the bee? How does it tolerate a compound that can hospitalize a human?
This research also has a conservation dimension. The cliff bee population is declining due to overharvesting, habitat destruction and climate change.
Scientists do not even have reliable baseline data on insect populations across the Hindu Kush Himalayan region, including the cliff bee, making it almost impossible to measure how fast things are changing.
This bee pollinates the high-altitude plants of the Himalayas, including the very rhododendrons whose toxins make the honey so curious and dangerous. We risk losing it before we even understand what we have.
This article is adapted from The Conversation, a nonprofit news organization dedicated to sharing the knowledge of experts. It was written by Prayan Pokharel, a research scientist at the University of Hohenheim. It was edited by Alexa Lardieri, the US health editor at the Daily Mail.
