But beekeeper Bayram Demirciler is adamant the honey his bees make high in the mountains above the Black Sea "has never caused any problems".

In good years his hives in the province of Rize in northeast Turkey produce up to 350 kilos of "mad" rhododendron honey.

The lush green Pontic Alps is home to a subspecies of rhododendron whose purple flowers drip with pollen that give "mad honey" its colour. They also contain a neurotoxin called grayanotoxin which can slow the heartbeat and that also packs a hallucinogenic punch.

"This honey is very good for people with hypertension," said Mustafa Oguz Alparslan, whose hives -- protected from sweet-toothed bears by an electric fence -- are even higher up the mountains at 1,400 metres (4,600 feet).

But eat too much and "it can also cause a rapid fall in blood pressure", warned the beekeeper, who said he always "tests his honey as it takes it out the hive".

- Knocked out a bear -

Doctors -- who recognise its virtues in small homoeopathic doses -- say the honey can slow the flow of blood to the brain, causing dizziness, fainting and even hallucinations.

Intoxication with "mad honey" was even documented in ancient times.

The Greek historian Strabo, who was born in the Black Sea region, said three of Pompey's Roman cohorts were put out of action by allies of the Pontian king Mithridates who left "pots of mad honey" in their path.

And it also figured in Agatha Christie's novel, "A Haunting in Venice", filmed last year by Kenneth Branagh.

The "Queen of Crime" -- who wrote part of "Murder on the Orient Express" in Istanbul -- had Rowena Drake kill her own daughter with it and even used it to give Belgian detective Hercule Poirot visions.

The honey can even put beasts on their back. A young brown bear made headlines in August 2022 when he was found unconscious near hives in Duzce province at the other end of Turkey's Black Sea. It had keeled over after overindulging on "mad honey", according to the ministry of forestry and agriculture.

The same month a bus driver travelling between Rize and the port city of Trabzon blamed the honey for him passing out and crashing into cars at a traffic light.

In his hospital in Trabzon, Professor Abdulkadir Gunduz treats between "30 and 100" people who have been knocked sideways by the honey in bad years.

The doctor said it was "possible that there are thousands of cases" across the wider region.

"If we have a sunny May and June, the bees will feast on the rhododendrons," making the honey even stronger, said Professor Gunduz, who has long researched the subject.

One particular detail pricked his interest. "More than 80 percent of the intoxicated patients are men over 50. Some believe (the honey) ups their sexual performance," he said.

- 'Almost died for nothing' -

In his shop in Cayeli, 20 kilometres from Rize, Necmettin Colak recommends his customers "take a soup spoon of the honey on an empty stomach".

For more mature clients in search of a sexual pick-me-up, he advises his chestnut honey instead, which he swears is "more efficient".

He stores his "mad honey" for several months to allow its more problematic attributes to dissipate before tasting it himself and selling it at 55 euros a kilo.

But not everyone takes such precautions. Alaattin Demirci, from Trabzon province, had to be taken to hospital after eating some "mad honey" in January 2021.

A few days later the sixtysomething posted photos of himself on Facebook on a drip, insisting that he would "never again" try it, saying he "almost died for nothing".