Senna - What is it & How to use

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

Effectiveness

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for SENNA are as follows:

Likely effective for…

  • Constipation. Taking senna by mouth is effective for short-term treatment of constipation. Senna is an FDA-approved nonprescription drug for adults and children ages 2 years and older. However, in children ages 3-15 years, mineral oil and a medication called lactulose might be more effective than taking senna. Senna also appears to be effective for treating constipation when used in combination with psyllium or docusate sodium. In elderly people, senna plus psyllium is more effective than lactulose for treating ongoing constipation. Senna plus docusate sodium is effective for treating constipation in the elderly and in people who have undergone anorectal surgery. Taking senna appears to be as effective as lactulose, psyllium, and docusate for relieving constipation in people taking opioids or loperamide.

Possibly effective for…

  • Bowel preparation before colonoscopy. Taking senna by mouth is as effective as castor oil and bisocodyl for bowel cleansing. Some evidence suggests that senna is also at least as effective as polyethylene glycol for bowel preparation. However, conflicting evidence exists. It is unclear if taking senna with polyethylene glycol is more effective than taking polyethylene glycol alone. Senna appears to be less effective than sodium phosphate for bowel cleansing. However, taking a combination of senna, sodium picosulfate, and polyethylene glycol appears to be more effective than sodium phosphate for bowel prepration prior to colonoscopy.

Possibly ineffective for…

  • Diagnostic imaging. Taking senna by mouth does not appear to improve imaging of abdominal organs.

Insufficient evidence to rate effectiveness for…

  • Hemorrhoids.
  • Irritable bowel disease.
  • Losing weight.
  • Other conditions.

More evidence is needed to rate the effectiveness of senna for these uses.

Dose

The following doses have been studied in scientific research:

BY MOUTH:

Senna is an FDA-approved nonprescription drug.

  • For constipation in adults and children age 12 and over: the usual dose is 17.2 mg daily. Don’t take more than 34.4 mg per day.
  • For constipation in children: 8.5 mg daily increased just enough to cause one bowel movement daily has been used.
  • For constipation in elderly people: 17 mg daily has been used.
  • For constipation following pregnancy: 28 mg in 2 divided doses has been used.

Safety Concerns

Senna is LIKELY SAFE for most adults and children over age 2 when taken by mouth, short-term. Senna is an FDA-approved nonprescription medicine. Senna can cause some side effects including stomach discomfort, cramps, and diarrhea.

Senna is POSSIBLY UNSAFE when taken by mouth long-term or in high doses. Don’t use senna for more than two weeks. Longer use can cause the bowels to stop functioning normally and might cause dependence on laxatives. Long-term use can also change the amount or balance of some chemicals in the blood (electrolytes) that can cause heart function disorders, muscle weakness, liver damage, and other harmful effects.

Special precautions & warnings:

Pregnancy and breast-feeding: Senna is POSSIBLY SAFE during pregnancy and breast-feeding when taken by mouth, short-term. It is POSSIBLY UNSAFE when taken by mouth long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver damage.

Although small amounts of senna cross into breast milk, it doesn’t seem to be a problem for nursing babies. As long as the mother uses senna in recommended amounts, senna does not cause changes in the frequency or consistency of babies’ stools.

Electrolyte disturbances, potassium deficiency: Overuse of senna can make these conditions worse.

Dehydration, diarrhea or loose stools: Senna should not be used in people with dehydration, diarrhea, or loose stools. It can make these conditions worse.

Gastrointestinal (GI) conditions: Senna should not be used by people with abdominal pain (either diagnosed or undiagnosed), intestinal blockage, Crohn’s disease, ulcerative colitis, appendicitis, stomach inflammation, anal prolapse, or hemorrhoids.

Heart disease: Senna can cause electrolyte disturbances and might make heart disease worse.

Interaction with medication

Moderate
Be cautious with this combination.
Birth control pills (Contraceptive drugs)
Ethinyl estradiol is a form of estrogen that’s in some birth control pills. Senna can decrease how much estradiol the body absorbs. Taking senna along with certain birth control pills might decrease their effectiveness.
Digoxin (Lanoxin)
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 of digoxin (Lanoxin).
Estrogens
Some pills used for hormone replacement therapy contain the chemical estrone. Senna can reduce the amount of estrone in the body. Other pills used for hormone replacement therapy contain the chemical ethinyl estradiol. Senna can decrease how much estradiol the body absorbs. Taking senna might decrease the effects of hormone replacement therapy.

Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.

Warfarin (Coumadin)
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)
Senna is a laxative. Some laxatives can decrease potassium in the body. “Water pills” can also decrease potassium in the body. Taking senna along with “water pills” might decrease potassium in the body too much.

Some “water pills” that can decrease potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.