← The ApothecaryBufonidaedried secretion of the parotoid and skin glands (chan su), dried skinFact-checked 24 October 2026

Toxic — not for home useOf 180 published poisoning cases in China (1961–2020), 53 died (29%), mostly from arrhythmia, conduction block and circulatory failure. Most came from eating toad meat mistaken for frog or toad eggs, but chan su itself, patent medicines and toad aphrodisiacs were also implicated. Symptoms begin within 30–60 minutes. Treatment in hospital includes gastric lavage, atropine or isoproterenol for slow heart rates, and haemoperfusion; case reports suggest digoxin-specific Fab antibody fragments can help.In an emergency, call your local emergency number or poison centre.

Asiatic toad

Bufo gargarizans

Also calledChan su (toad venom, Chinese) · Chusan Island toad

In older monographsBufo bufo gargarizans, Venenum Bufonis (the drug)

The dried venom of this East Asian toad, chan su, is a potent Chinese medicine for abscesses, sore throats and toothache, and an ingredient of more than 100 patent medicines such as Liu Shen Wan. Its bufadienolides act on the heart like digitalis: a review of 180 poisonings found nearly a third were fatal. It is a poison with medical uses, not a home remedy.

What it is used for

Cancer: drugs and supportive care
Limited
Huachansu and cinobufacini, Chinese preparations of toad venom or skin, are used alongside chemotherapy. Meta-analyses of Chinese trials (10 RCTs, 881 people in breast cancer; trials in advanced colorectal cancer) reported better response rates and fewer chemotherapy side effects, but rated the evidence low to moderate because the trials were of poor quality.^2,3
Viral infections
Limited
Liu Shen Wan, a polyherbal pill containing toad venom, added to standard treatment for shingles in 21 small trials (1,478 people) shortened healing time and lowered the rate of post-herpetic neuralgia; trial quality was limited and the toad's share of the effect is unknown.^4,1
Sore throat
Traditional
Chan su has been used in Chinese medicine for sore throats, abscesses and toothache; modern patent medicines for these uses are multi-ingredient.¹
Toothache
Traditional
A traditional Chinese use of the venom, applied in small amounts; no modern trials found.¹
Bacterial infections
Traditional
The venom and dried toad skin are used for abscesses and childhood sores in Chinese medicine.¹

How it is prepared

powder

In Chinese practice the dried venom is ground and given in minute amounts within pills, or applied externally as powder or ointment.

dry extract / capsule

Chinese patent medicines containing toad venom include Liu Shen Wan, Chansu Wan and Shexiang Baoxin Wan; huachansu and cinobufacini are hospital preparations used in oncology.

Amounts are as recorded by the named source, not a recommendation.

Safety

Pregnancy: Avoid
Breastfeeding: Avoid
Children: Children under 15 and adults over 60 accounted for most deaths in the poisoning series; children have been poisoned by eating toad eggs.

Interactions with medicines

digoxin and other cardiac glycosidesMajorBufadienolides act on the same Na+/K+-ATPase site as digoxin; additive toxicity with arrhythmia and heart block is expected.

Interaction checker →

Do not use if

Not for home use in any form
Heart disease or heart-rhythm disorders
Pregnancy and breastfeeding: no safety data for a cardiac poison

Side effects

Vomiting (95% of poisonings), nausea, abdominal pain, diarrhoea
Chest tightness, palpitations, slow heart rate and heart block
Dizziness, headache, numbness of the limbs, drowsiness

In the healing traditions

Traditional Chinese Medicine
Chan su (Venenum Bufonis)
Dried secretion of the parotoid and skin glands for abscesses, sore throat, toothache and other ailments; the dried toad body ('toad-cortex') for childhood sores, chronic bronchitis and abscesses. Toads appear as medicine in the early Chinese text 'List of Famous Doctors'.
'List of Famous Doctors'; Chinese Pharmacopoeia
Modern pharmacology
Bufadienolides (bufalin, cinobufagin, resibufogenin)
Studied as Na+/K+-ATPase inhibitors with digitalis-like effects on the heart and as anticancer compounds. Huachansu capsules and cinobufacini capsules are Chinese patent medicines used as adjuncts in cancer care.

Active compounds

bufadienolides: 142 reported; gamabufotalin, telocinobufagin, bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin make up over 85%. They inhibit cardiac Na+/K+-ATPase at the digitalis binding site.
bufotenine and 5-MeO-DMT: indole alkaloids; hallucinogenic

History

The dried venom has been used in Chinese medicine for centuries, and toads are recorded in the early text 'List of Famous Doctors'. In 1998 an antimicrobial peptide was isolated from this toad and patented. China now has over 100 patent medicines containing toad ingredients.

Sources

Reference, not prescription. Nothing here is medical advice. Herbs can interact with medicines and be dangerous in pregnancy; tell your doctor or pharmacist about anything you take.