The Health Benefits of Senna

This common laxative has been used to treat constipation for centuries

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The herb senna has been used for thousands of years to combat constipation. It is FDA-approved as an over-the-counter stimulant laxative for the treatment of constipation or as a bowel cleanse prior to surgery or diagnostic testing of the digestive tract.

Senna's active agent is sennosides, a plant compound in the anthraquinone family. Sennosides work by irritating the lining of the bowel, creating a powerful laxative effect. When taken by mouth, senna typically produces a bowel movement in six to 12 hours, but it can be effective in as little as 10 minutes when taken rectally.

Also Known As

  • Sennoside
  • Senna glycoside
  • Cassia senna
senna for constipation
Verywell / Gary Ferster

Health Benefits

Senna is considered effective for the short-term treatment of constipation in adults and children. The herb is also purported to treat anal fissures and hemorrhoids, and to promote weight loss, though there is limited research to support these claims.

Constipation in Adults

For treating constipation in adults, senna is effective when used alone or in combination with psyllium or docusate sodium, according to the National Institutes of Health (NIH).

Constipation in Seniors

In elderly patients, senna used with psyllium or docusate sodium is effective for treating ongoing constipation, according to the NIH.

Constipation in Children

The natural laxative is often prescribed for pediatric patients. A 2018 literature review and analysis published in the Journal of Pediatric Surgery found that long-term use of senna appears to be safe for children with chronic constipation, although side effects such as a blistering diaper rash may appear with prolonged skin contact to feces produced from senna.

Opioid-Related Constipation

For people taking opioid pain relievers, constipation is a common side effect. Senna effectively treats constipation as well as lactulose, psyllium, and docusate sodium in opioid users, notes the NIH.

Colonoscopy Prep

Senna is often recommended for bowel preparation before a colonoscopy. According to the NIH, when using senna for a bowel cleanse, it is most effective with either polyethylene glycol, sodium picosulfate, or a combination of all three.

Possible Side Effects

Side effects of senna may include abdominal cramps and pain from muscle contractions, dark or discolored urine, electrolyte imbalance, nausea, rash, and swelling of the face, lips, or tongue.

Prolonged use of senna may lead to dark pigmentation in the colon, called melanosis coli. In large doses and prolonged use, senna has been linked to liver toxicity.

The American Herbal Products Association (AHPA) recommends that you discontinue use of senna in the event of diarrhea or watery stools.

In children who are not toilet trained, senna use is linked to diaper rash with blisters that may be severe. Healthcare providers recommend changing your child's diaper immediately after stooling while taking senna and cleaning the diaper area thoroughly. If your child develops a diaper rash with blisters or cracked skin, call your pediatrician.

Senna should not be used for more than seven consecutive days unless under a healthcare provider's supervision. Discontinue use and call your healthcare provider if you experience bloody diarrhea or prolonged abdominal pain after senna use.


Senna or other anthraquinone-containing herbs should not be used by people with abdominal pain, diarrhea, diverticular disease, ulcerative colitis, Crohn's disease, severe hemorrhoids, blood vessel disease, congestive heart failure, heart disease, severe anemia, abdominal hernia, gastrointestinal cancer, recent colon surgery, liver disease, or kidney disease.

The AHPA also recommends that you consult your healthcare provider prior to use if you are pregnant or nursing.

Senna may interact with drugs called calcium channel blockers and the drug Indocin (indomethacin).

Dosage and Preparation

Senna used for medicinal purposes is derived from the leaves and fruit of the senna plant. Senna products made from the fruit are gentler than preparations made from the leaf.

Senna comes in tablets and liquid formulations, and is also available as a tea.

Dosing varies based on patient age and why senna is being used. Talk to your healthcare provider to find the right dose for you (and do not exceed it).

Here are some general guidelines:

Adults Constipation 17.2 milligrams (mg) daily; maximum: 34.4 mg twice a day
Adults (Postpartum) Constipation 28 mg daily taken in two 14 mg doses
Adults (Elderly) Constipation 17.2 mg daily
Adults Bowl Preparation

75 mg sennosides taken the day before a colonoscopy; maximum: 150 mg taken as one or two doses

Children (2 to 5 Years) Constipation 1/2 tablet (4.3 mg sennosides) daily; maximum: 1 tablet (8.6 mg sennosides) twice daily
Children (6 to 11 years) Constipation

1 tablet (8.6 mg sennosides) daily; maximum: 2 tablets (17.2 mg sennosides) twice daily

Children (12 years+) Constipation

2 tablets (8.6 mg sennosides per tablet) once daily; maximum: 4 tablets (34.4 mg sennosides) twice daily

Other Questions

Is senna safe to take every day?
While the herb is generally regarded as safe and may be prescribed for everyday use, long-term use may pose concerns. Follow your healthcare provider's recommendations.

Will senna give me a stomach ache?
Senna works to treat constipation by irritating the lining of the intestines, which stimulates the digestive tract to move stool through it. As such, some people report abdominal cramps after taking senna, which resolves once a bowel movement is complete.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Vilanova-Sanchez A, Gasior AC, Toocheck N, et al. Are Senna based laxatives safe when used as long term treatment for constipation in children? J Pediatr Surg. 2018;53(4):722-727. doi:10.1016/j.jpedsurg.2018.01.002

  3. Cleveland Clinic. Senna oral solution.

  4. Abu Baker F, Mari A, Feldman D, Suki M, Gal O, Kopelman Y. Melanosis Coli: A Helpful Contrast Effect or a Harmful Pigmentation? Clin Med Insights Gastroenterol. 2018;11:1179552218817321. doi:10.1177/1179552218817321

  5. National Institute of Diabetes and Digestive and Kidney Diseases. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Senna.

  6. American Herbal Products Association. Code of Ethics and Business Conduct: IV. Stimulant Laxatives.

  7. Mayo Clinic. Senna (oral route): proper use.