Senna alexandrina (previously Cassia angustifolia)


Senna is a shrub that grows to one metre and bears pretty yellow flowers. Once divided into two genuses, all species of senna are now grouped as Senna alexandrina. Knowledge of this herb’s laxative properties is recorded as far back as the ninth century when, legend has it, the great caliph of Baghdad suffered with such blocked bowels that his physicians searched high and low for a cure that didn’t cause their leader severe abdominal pain. Enter the famous pharmacist and medical practitioner Mesue the Elder, who introduced senna, which he administered in small doses, and the caliph’s problems were cured. Today senna is still widely used as an effective laxative.

Parts used

The dried leaves or pods are used to make medicine.


The main active ingredients in senna are chemicals called sennosides, which stimulate and irritate the bowel lining, creating a laxative effect.

Medicinal uses

Senna is an FDA- and German Commission E-approved nonprescription laxative that is used to treat constipation and, on occasion, to clear the bowel prior to diagnostic tests such as colonoscopy. Senna is sometimes used for irritable bowel syndrome, haemorrhoids and to lose weight, leading to warnings against long-term use.

Senna is prescribed to:

  • Encourage natural bowel action.
  • Improve lazy bowel syndrome.
  • Ensure a soft stool after anal-rectal surgery.


Talk to your medical practitioner before taking any herbal supplements.
When used for a short period and in the correct dosage, senna appears to be quite safe. However, large doses taken over an extended period can cause dehydration, stop the bowels from functioning normally and may increase the risk of colon cancer. Long-term use can also cause an imbalance of vitamin K, electrolytes and potassium in the blood that may lead to a variety of disorders, including impaired heart function and liver damage. Short-term use is thought to be safe during pregnancy and when breast-feeding, but it is best to consult your healthcare professional if in doubt. Avoid senna if you have abdominal pain, diarrhoea, ulcerative colitis or haemorrhoids, and do not use to treat irritable bowel syndrome or to boost weight loss.

Flora Force Products containing Senna

Domestic & culinary uses

Senna is not used as a culinary ingredient.


Indigenous to the Middle East and north-eastern Africa and cultivated in India, senna is a perennial plant that flourishes in rich soils.

Photo credits

  1. By Lalithamba from India [CC-BY-2.0], via Wikimedia Commons
Information in our herb library is intended only as a general reference for further exploration. It is not a replacement for professional health advice and does not provide complete dosage information, format recommendations, toxicity levels, or possible interactions with prescription medicines. Accordingly, this information should only be used under the direct supervision of a suitably qualified health practitioner such as a registered homeopath, naturopath or phytotherapist.