Aconite In Herbal Tea Sends Two To ER In San Francisco

Health authorities in San Francisco have warned against consuming herbal tea from a Chinatown shop after two people took critically ill.

San Francisco Department of Public Health advised against consuming tea from Sun Wing Wo at 1105 Grant avenue. The alert comes after two separate instances of a man and a woman developing acute symptoms of poisoning after consuming herbal tea bought from the store were reported. Lab tests revealed the tea contained aconite, a plant-based toxin known to cause fatalities.


“In separate incidents in February and March, a woman in her 50s and a man in his 30s became critically ill within an hour of drinking tea made from leaves supplied by the same San Francisco herbalist,” KRON4 reported, quoting an official press release. “Each quickly developed weakness, and then life-threatening abnormal heart rhythms, requiring resuscitation and intensive hospital care. A plant-based toxin, Aconite, was found in lab tests of the patients and the tea samples they provided.”

Herbal Tea, Aconite Use As Poison

Aconite toxin is produced by a family of flowering plants known as aconitum, monkshood, wolfsbane and ironically “Queen of all Poisons,” with herbal uses in traditional medicine and use of leaf extract in making tea. In 2014, a U.K. gardener Nathan Greenway died when he accidentally brushed against the plant. According to The Telegraph, he had symptoms of poisoning for 29 hours before he died. His case was initially suspected to be an Ebola infection.


Besides its use in making herbal tea, aconite has historically been used in warfare to poison arrow tips. All portions of the plant are known to be toxic, with roots being more potent than the rest. According to the British Homeopathic Association, several legends point to the plant’s nature that give it various names.

“Aconite, or aconitine the poisonous alkaloid derived from it, has been known since antiquity. Indeed, Pliny the Elder recounts that it takes its name from Aconae, in the Black Sea, its supposed place of origin. Legend says that this was the place where Hercules dragged Cerebus, the three-headed dog that guarded Hades. As the dog drooled during the fight, poison fell on the plant that grew there, tainting it and making it poisonous forever.”

Aconite Poisoning Symptoms

Aconite neurotoxin produces symptoms within an hour of entering the body. Facial tingling and numbness owing to effects on motor nerves, as well gastrointestinal symptoms including diarrhea and nausea, are among the first symptoms. Heart rate and pulse can drop significantly, followed by an onset of irregular heartbeat rhythm and reduced blood pressure. However, herbal tea preparation can make the substance less toxic, according to an NIH publication.

“Soaking and boiling during processing or decoction preparation will hydrolyze aconite alkaloids into less toxic and non-toxic derivatives. However, the use of a larger than recommended dose and inadequate processing increases the risk of poisoning.”

That notwithstanding, KRON4 reports San Francisco poisoning incident has prompted health officials to clear the two herbal tea products that caused poisoning from the store’s shelves, even as efforts are on to trace the source of the toxin in the products. Those who have consumed herbal tea brought from the store without experiencing acute symptoms are safe but have been advised to stay alert.


SF Public Health officer Dr. Tomas Aragon advised disposing of remaining herbal tea purchased from the store. “Anyone who has purchased tea from this location should not consume it and should throw it away immediately,” he said. “Aconite poisoning attacks the heart and can be lethal.”

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