The leaves or pods of the senna plant (Cassia senna) have been used by Arab physicians for their laxative properties since at least the ninth Century. Today, senna is a U.S. Food and Drug Administration (FDA)-approved nonprescription drug and an ingredient in several commercial laxatives.
There are over 400 known species of Cassia. Both the leaves and the seedpods (fruit) have laxative activity, due to the presence of compounds called anthraquinones. These compounds found in senna are also found in other plants with laxative properties, including cascara (Cascara sagrada), rhubarb (Rheum spp.), and aloe (Aloe vera). Senna accelerates defecation, in contrast to softening the stools, as some laxatives do. When taken at much higher than recommended doses or when used for the long term (laxative abuse), adverse effects, such as low blood potassium, may occur.
Some evidence supports the use of senna in adults for the treatment of chronic constipation or constipation induced by childbirth or drugs. In children, the available evidence suggests that mineral oil and lactulose may be safer and more effective than senna for treating chronic constipation. Some experts believe that senna is a more acceptable laxative than cascara or aloe for drug-induced constipation. Approximately 80% of terminal cancer patients who are taking opioids for pain relief require laxatives. Some evidence suggests that senna may be as effective and safe as lactulose for these patients.

Related Terms

Aden senna, Agiocur®, Agiolax®, Alexandrian senna, Alexandrinische Senna (German), barakol, casse, Cassia acutifolia, Cassia alata, Cassia angustifolia, Cassia marilandica, Cassia obtusifolia L., Cassia senna, Cassia tora L., Cassiae senna, cassine, dianthrones, extractum Sennae, Fletcher's Castoria®, Glysennid®, hairy roots, Indian senna, Khartoum senna, locust plant, Lunelax®, Mecca senna, Nubian senna, Perdiem, Prunasine®, Pursennid®, rhein, rhein 8-O-glucoside, rheinanthrone, sena alejandrina (Spanish), séné d'Egypte (French), Senna alata (L.) Roxb. (Fabaceae), Senna alexandrina spp., Senna didymobotrya (Fresen.) H.S.Irwin & Barneby, senna fruit, Senna obtusifolia (L.), Senna occidentalis (L.) Link (Fabaceae), senna pods, Senna racemosa, Senna spectabilis, Senna tora (L.) Roxb., Sennae folium, Sennae fructus, Sennatin®, sennidine monoglycosides, sennoside A, sennoside B, Senokot®, Sofsena™, Tinnevelly senna fruits, true senna, winged senna, X-prep®.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Constipation (children) (Grade: C)
The available evidence suggests that mineral oil and lactulose may be safer and more effective laxatives than senna for treating children with chronic constipation. Further research is required before conclusions may be made.
Constipation (chronic) (Grade: C)
Although senna is commonly used to reduce constipation, the available clinical research is mixed. Some studies have shown that senna may be more effective than some other laxatives and have fewer side effects. Further trials are needed before a conclusion may be made.
Constipation (drug-induced) (Grade: C)
Some evidence supports the use of senna as an adjunct therapy in the treatment of cancer patients who have constipation as a result of taking opioids for pain. Further research should assess the length of time such patients may safely use senna.
Constipation (postoperative) (Grade: C)
Senna has been examined as a potential treatment for postoperative constipation. Additional research is needed before a conclusion may be made.
Diagnostic procedure (abdominal area) (Grade: C)
Senna has been examined as a method for preparing the bowel before diagnostic procedures that require clear visualization of the abdominal area. Further studies are needed in this area.
Laxative/bowel preparation for procedures (colonoscopy) (Grade: C)
Data on the use of senna for cleaning the colon in preparation for colonoscopy are mixed. Some adverse effects have been reported with this use. Additional research is needed before a conclusion can be made.