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Botanical illustration of Siamese Cassia
MedicinalSourced entry

Siamese Cassia

Senna siamea

A tree whose leaves are eaten in Thailand, where it is called khi lek and traditionally used for sleep. A calming product made from it caused cases of hepatitis.

What is Siamese Cassia?

Plant family
Fabaceae, the pea and bean family
Parts used
The leaves, pods and heartwood
Genus
Senna
Species
siamea

Also called

Cassia

Regional names

Khi Lek, Khi-lek

Older scientific names

Cassia siamea

Traditionally used for

  • Sleep (traditional)
  • Anxiety (traditional)
  • Fever
  • Food

Traditionally described as

  • May make you feel sleepy (in animals)

Health topics

Where Siamese Cassia appears in symptom search, and why. Being listed doesn't mean it's a proven treatment.

  • Anxiety

    Sold in Thailand as an anti-anxiety product, but animal tests found no anti-anxiety effect, and it has caused hepatitis.

  • Liver Safety Warnings

    Barakol tablets made from Siamese cassia caused hepatitis in 12 people in Thailand.

  • Sleep Problems (Insomnia)

    Traditionally used for insomnia. Its compound barakol made animals sleepy, but it hasn't been tested in people.

Natural compounds

Barakol

Safety

Toxicity testing

  • In Thailand, 12 people developed hepatitis (liver inflammation) after taking barakol tablets for 3 to 180 days, most with loss of appetite and yellow skin or eyes. Liver damage wasn't linked to the dose. Two people who restarted it had liver problems again. Everyone recovered within 2 to 20 weeks of stopping.[1]

What does the research say?

Traditional use

These are traditional uses, not proven treatments.

  • Siamese cassia has traditionally been used for fever, skin diseases, high blood pressure, insomnia, diabetes and asthma.[2]

  • Siamese cassia is used in Thai cooking, and in traditional Thai remedies, including for diabetes.[3]

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

  • In mice and rats, barakol, the plant's main calming compound, reduced activity, made more animals fall asleep and made sleep last longer. It didn't reduce anxiety in standard animal tests.[4]

  • In rats given barakol by mouth, once or daily for 30 days, it didn't reduce anxiety but had a calming effect, making them explore less.[5]

Research in people

  • Barakol from Siamese cassia has been sold in Thailand as a natural anti-anxiety product. No clinical trials of its effects in people were found.[1]

In short

Barakol, its calming compound, has caused liver inflammation (hepatitis).

Sources

  1. [1] Acute hepatitis associated with Barakol — Journal of the Medical Association of ThailandPeer-reviewed study
  2. [2] Cassia siamea-Derived Silver Nanoparticles: Synthesis and Their Impact on Male Fertility Through Biochemical and Histopathological Insights in Rats — Biological Trace Element Research · DOI: 10.1007/s12011-025-04658-2Peer-reviewed study
  3. [3] Antidiabetic Potential of Senna siamea: α-Glucosidase Inhibition, Postprandial Blood Glucose Reduction, Toxicity Evaluation, and Molecular Docking — Scientifica · DOI: 10.1155/sci5/6650349Peer-reviewed study
  4. [4] CNS inhibitory effects of barakol, a constituent of Cassia siamia Lamk. — Journal of Ethnopharmacology · DOI: 10.1016/s0378-8741(02)00206-4Peer-reviewed study
  5. [5] Behavioral effects of acute and chronic oral administration of barakol in rats — Journal of the Medical Association of ThailandPeer-reviewed study

This information is educational and traditional in nature, and is not a substitute for professional medical advice.