Overview

Senna is the fruit (pod) or leaf of the plant Senna alexandrina. It is approved in the US as a laxative for short-term treatment of constipation.

Senna contains many chemicals called sennosides. Sennosides irritate the lining of the bowel, which causes a laxative effect.

Senna is an FDA-approved over-the-counter (OTC) laxative. It is used to treat constipation and also to clear the bowel before procedures such as colonoscopy. People also use senna for irritable bowel syndrome (IBS), hemorrhoids, weight loss, and many other conditions, but there is no good scientific evidence to support these uses.

Uses & Effectiveness

Likely Effective for

  • Constipation. Senna is an FDA-approved nonprescription (OTC) drug for adults and children ages 2 years and older. It should be taken at bedtime and tends to work within 6-12 hours. It might cause stomach upset and diarrhea. Senna should not be used for more than 1 week without the supervision of a healthcare provider.

Possibly Effective for

  • Emptying the colon before a colonoscopy. Taking senna by mouth might help empty the colon before a colonoscopy. Prior to a colonoscopy, your doctor will recommend a specific regimen to use in order to ensure that your colon is empty prior to the procedure.

There is interest in using senna for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Senna is likely safe for most adults when used for up to 1 week. Senna is an FDA-approved nonprescription (OTC) medicine. It can cause some side effects including stomach discomfort, cramps, and diarrhea.

Senna is possibly unsafe when used for longer than 1 week or in doses above 34.4 mg sennosides twice daily. Long-term use can cause the bowels to stop functioning normally and might cause dependence on laxatives. Long-term use can also cause liver damage and other harmful effects.

Special Precautions and Warnings

When taken by mouth: Senna is likely safe for most adults when used for up to 1 week. Senna is an FDA-approved nonprescription (OTC) medicine. It can cause some side effects including stomach discomfort, cramps, and diarrhea.

Senna is possibly unsafe when used for longer than 1 week or in doses above 34.4 mg sennosides twice daily. Long-term use can cause the bowels to stop functioning normally and might cause dependence on laxatives. Long-term use can also cause liver damage and other harmful effects.

Pregnancy: Senna is possibly safe when taken by mouth during pregnancy for up to 1 week. It is possibly unsafe when taken by mouth for longer than 1 week or in high doses. This has been linked to serious side effects including laxative dependence and liver damage.

Breast-feeding: Senna is possibly safe when taken by mouth during breast-feeding for up to 1 week. Small amounts of senna cross into breast milk, but it doesn't seem to be a problem for nursing babies. As long as senna is used in recommended amounts, it doesn't cause changes in the babies' stools.

Children: Senna is likely safe for children over age 2 when taken by mouth for up to 1 week. It is an FDA-approved nonprescription (OTC) medicine that can cause some side effects including stomach discomfort, cramps, and diarrhea. Senna is possibly unsafe when taken by mouth for longer than 1 week or in high doses. Children ages 2-5 shouldn't take more than 8.6 mg sennosides twice daily. Children ages 6-11 shouldn't take more than 17.2 mg sennosides twice daily. Children 12 years and older shouldn't take more than 34.4 mg sennosides twice daily.

Gastrointestinal (GI) conditions: Senna should not be used by people with stomach pain, intestinal blockage, inflammatory bowel disease, diarrhea, appendicitis, stomach inflammation, or hemorrhoids.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Digoxin (Lanoxin) interacts with Senna

    Senna is a type of laxative called a stimulant laxative. Stimulant laxatives can decrease potassium levels in the body. Low potassium levels can increase the risk of side effects from digoxin.

  • Warfarin (Coumadin) interacts with Senna

    Senna can work as a laxative. In some people, senna can cause diarrhea. Diarrhea can increase the effects of warfarin and increase the risk of bleeding. If you take warfarin, do not take excessive amounts of senna.

  • Water pills (Diuretic drugs) interacts with Senna

    Senna is a laxative. Some laxatives can cause diarrhea and decrease potassium levels. "Water pills" can also decrease potassium levels. Taking senna along with "water pills" might make potassium levels drop too low.

  • Estrogens interacts with Senna

    Taking senna might decrease the effects of estrogen. Senna can reduce the amount of estrogen in the body and how much estrogen the body absorbs.

Dosing

Senna is most often used by adults in doses of 17.2 mg sennosides by mouth, once or twice daily. Recommended doses in children vary by age. Speak with a healthcare provider to find out what dose might be best for a specific condition.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

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