A 59-year-old man in Nepal ate three to four teaspoons of locally sourced honey, roughly 15 to 20 milliliters. About 60 to 80 minutes later, he was nauseated, vomiting repeatedly, and dizzy. His heart rate had fallen to 42 beats per minute, and his blood pressure had dropped to 60/40.
The culprit was mad honey, made by bees that feed on nectar from certain rhododendron species containing natural toxins called grayanotoxins. The case, published March 27 in the International Journal of Emergency Medicine by physicians from Mercy City Hospital in Rupandehi, Nepal, and colleagues at other institutions in Nepal, India, and the U.K., shows how a small amount of a folk remedy can produce a classic toxic reaction.
From a Spoonful of Honey to the Emergency Room
The man remained awake and alert, with no chest pain or breathing trouble, according to the report. He had chronic obstructive pulmonary disease managed with inhalers, took no heart medications, and had no history of substance use.
His electrocardiogram showed sinus bradycardia, meaning his heart was beating in a normal pattern but far too slowly. It showed no signs of a heart attack, and blood tests for heart damage came back normal.
Because there is no routine lab test for grayanotoxin, and the hospital, like many in Nepal, had no facility to measure it, doctors had to work by elimination. They ruled out heart attack, low fluid volume, sepsis, an overdose of beta-blocker blood pressure drugs, and organophosphate pesticide poisoning. His honey history, combined with the classic symptom pattern, pointed to mad honey poisoning.
He received intravenous fluids and a single 0.6-milligram dose of atropine, a drug that counters the nerve signals slowing the heart. His heart rate and blood pressure steadily improved, and no further doses were needed. After 24 hours of observation, he was discharged and advised to avoid wild or unprocessed honey. Blood tests and an electrocardiogram were normal at a follow-up visit two weeks later.
How Rhododendron Toxins Slow the Heart
In Nepal, the toxic honey comes from rhododendron species known locally as Laliguras, which grow in the country's hilly and Himalayan regions. At high altitudes, it is produced by the Himalayan giant honey bee, the world's largest honeybee species, which can reach 3 centimeters in length. The authors note that grayanotoxin-rich plants also grow in Brazil, Japan, Turkey, and North America.
Grayanotoxins bind to sodium channels in nerve and heart cells and keep them from shutting off properly. The result is heightened activity of the vagus nerve, which slows the heart, lowers blood pressure, and upsets the stomach. A 2012 review in Cardiovascular Toxicology describes dizziness, low blood pressure, and atrioventricular block, a disruption of the heart's electrical signaling, as hallmarks of poisoning.
Mad honey has long been used in folk medicine for conditions such as high blood pressure, diabetes, and indigestion, though the Nepali authors note that scientific evidence supporting those uses is scarce. They add that its use as an aphrodisiac and for recreation is growing.
One of Several 2026 Reports Out of Nepal
The case is one of several mad honey reports from Nepal published this year. A case series published April 5 described seven patients treated at a rural primary care hospital between June 2024 and January 2025. All were men between 36 and 66 who had consumed 5 to 25 milliliters of wild honey. Five had the classic picture of dizziness, vomiting, slow heart rate, and low blood pressure. The other two arrived with features of anaphylaxis, a severe allergic reaction, including swelling, hives, and breathing difficulty, without an initially slow heart rate. All improved within 24 to 48 hours with supportive care.
That overlap is one reason diagnosis can be tricky. Symptoms can resemble a cardiac emergency, an allergic reaction, or another poisoning, and doctors rely heavily on patients mentioning what they ate.
Mad Honey Poisonings Have Surfaced in the U.S.
Mad honey is not only a Himalayan problem. The 2012 review warned that grayanotoxin-containing products sold online could pose an increasing risk, and cases have appeared in the United States.
A 2024 case series described three people treated at the Burning Man festival in Nevada after recreational mad honey use. They had dizziness, nausea, vomiting, and diarrhea, along with significant bradycardia and low blood pressure, and recovered with atropine and IV fluids. In 2025, the Utah Poison Control Center described a 50-year-old woman who took mad honey obtained from India for stomach symptoms and developed chest pain, lightheadedness, hallucinations, and low blood pressure. She improved with atropine and fluids and went home the next day.
The Utah center notes that grayanotoxin-producing plants grow in the United States, including western azalea and mountain laurel. It also notes that significant effects have been reported after a tablespoon of honey or less.
The good news is that outcomes are usually favorable. The Nepali authors' review of the literature found no confirmed deaths from mad honey poisoning, and most patients recover with supportive care. But toxin levels vary from honey to honey, so the size of a harmful dose is unpredictable.
The authors stressed that mad honey poisoning is a reversible cause of slow heart rate and low blood pressure, as long as clinicians recognize it. Anyone who develops dizziness, vomiting, fainting, or a very slow pulse after eating unusual or imported honey should seek emergency care and tell medical staff exactly what they consumed. For questions about a possible exposure, U.S. residents can call Poison Help at 1-800-222-1222.
Key Questions Answered
What is mad honey?
It is honey made from the nectar of certain rhododendron plants that contain grayanotoxins, natural toxins that affect nerve and heart cells.
What happened in the Nepal case?
A 59-year-old man ate three to four teaspoons of local honey and, about an hour later, developed vomiting, dizziness, a heart rate of 42, and blood pressure of 60/40.
How is mad honey poisoning treated?
Treatment is supportive. This patient received IV fluids and a single dose of atropine and stabilized quickly. He was discharged after 24 hours of observation.
Can doctors test for grayanotoxin?
Not routinely. Diagnosis usually depends on a history of honey consumption and ruling out other causes, such as a heart attack or drug overdose.
Has mad honey caused illness in the U.S.?
Yes. Published reports include three festival-goers treated at Burning Man and a woman described by the Utah Poison Control Center who used mad honey obtained from India.
Is regular store-bought honey a concern?
There is no evidence that ordinary commercial honey poses this risk. Reported poisonings involve honey from grayanotoxin-producing plants, often wild, imported, or sold specifically as mad honey.
