Senna laxative : Uses, ingredients, dosage, side effects, drug interactions and during pregnancy and nursing


What is Senna?

Senna is an FDA approved herb and nonprescription laxative. Senna is a natural medicine that contains sennosides which are derived from the leaves of the senna plant. Sennosides irritate the lining of the bowel causing a laxative effect. Because there are many uses of senna which are not approved by FDA, therefore, it should not be used in place of the prescribed medication.


The medicine is made by using the leaves and fruits of its plant. It is used for the treatment of constipation, to clear the bowel before the colonoscopy (diagnostic tests), irritable bowel syndrome, hemorrhoids and weight loss too.

Is Senna a safe laxative?

Senna is an herbal product and its fruit is gentler than its leaf. This creates a warning against the long-term use of senna leaf (but not senna fruit) by American Herbal Products Association (AHPA). As per AHPA recommendations: the senna leaf labels should have these indications:


“Do not use this product if you have abdominal pain or diarrhea. Consult a healthcare provider prior to use if you are pregnant or nursing. Discontinue use in the event of diarrhea or watery stools. Do not exceed recommended dose. Not for long-term use. ”

Senna category, molecular formula, IUPAC name, molecular weight, molecular structure

Pharmacologic Category – Laxative, Stimulant

Molecular formula:  C42H38O20

IUPAC name: 9-[(9R)-2-carboxy-4-hydroxy-10-oxo-5-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-9H-anthracen-9-yl]-4-hydroxy-10-oxo-5-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-9H-anthracene-2-carboxylic acid

Molecular weight:  862.746 g/mol

Molecular structure:

What is the classification of Senna?

What is the pharmacology of senna?

Senna comes under a group of stimulant laxatives of anthraquinone group. It induces the defecation by enhancing the peristaltic activity on the intestine as it causes the direct action on intestinal mucosa or nerve plexus thereby increasing the motility and treat constipation.

Pharmacokinetics of senna

Senna undergoes hepatic metabolism and excreted in feces (via bile) and urine. It shows its onset of action within 6 to 24 hours when taken orally.

What are the indications of the senna?

Senna is indicated for the treatment of constipation, on a short-term basis. In certain medical procedures and before surgery, it is used to empty the bowel contents. It comes under the class stimulant laxatives. It causes a bowel movement by increasing the activity of intestine.

What is the herb Senna used for?

What are the off-label uses of senna?

Senna is also used for colonic cleansing before the colonoscopy (adjunct), it is also used as an adjunct to reduce the amount of polyethylene glycol (PEG) solution as senna is better tolerated by the patients as compared to polyethylene glycol solution. The lower quantity of PEG solution can reduce the quality of bowel preparation.  It is also used to cleanse the colon by means of emptying the bowel contents, prior to surgery or other medical procedures.

What happens if I miss a dose of senna laxative?

You should skip the missed dose if it is the almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What should I avoid during senna use?

Any restrictions on food, beverages, or activity as per instructed by your healthcare provider.

What are the side effects of senna?

In patients receiving a bulk the laxatives product that contains 82% psyllium and 18% senna, here, senna can induce esophageal impaction and duodenal bezoars as gastrointestinal side effects.  Senna can rarely induce hypersensitivity, One case has been reported involving a factory worker who developed IgE-mediated asthma and rhinoconjunctivitis five months after exposure to senna.

You should seek emergency medical attention if you see any of these signs of allergic reaction to senna, hives, swelling of your lips, face, tongue, or throat and difficulty in breathing.

Call your healthcare provider at once if you have a serious side effect such as:

  • Severe stomach pain, severe diarrhea, watery diarrhea
  • Weight loss
  • Worsening constipation after you stop taking senna
  • Enlargement of your fingers and toes
  • Low potassium (confusion, uneven heart rate, extreme thirst, increased urination, leg discomfort, muscle weakness or limp feeling); or nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious senna side effects which are ignored by many individuals but medical attention should be considered if they become severe or long-lasting, such effects may include:

  • Stomach cramps
  • Bloating, gas, mild diarrhea
  • Numbness or tingling in fingers and toes
  • Joint pain
  • Discolored urine

How to cope with side effects?

In case you got diarrhea (as a side effect of senna), you should drink plenty of fluids in order to meet the water loss from the body due to diarrhea, you can also take some oral rehydration solution.

You should not take any medication for treating diarrhea without proper instructions given by your doctor. Your doctor can also reduce the dose of senna and adjust the dose as per your health condition. Your doctor can also reduce the dose of senna in case of stomach cramps that you may get the as severe side effect of senna and reduce the dose can really help to treat the condition.

Is senna safe during pregnancy?

Senna comes under pregnancy category C and is decided by Food and Drug Administration. There are no signs or reports of teratogenicity have been reported with the use of senna, however, there are no controlled data in human pregnancy. Senna should only be given in pregnancy if the benefit outweighs the risks.

Is senna safe for a breastfeeding mother?

It is reported that senna is not excreted in human milk. However, a metabolite of senna can be excreted in human milk. Senna is a prodrug which is metabolized into active glucosides of rhein (called sennosides) and rhein is excreted in human milk but in very small amounts. In nursing infants, no side effects are noted. Senna is considered as compatible with breastfeeding by The American Academy of Pediatrics.

Who can take senna and who cannot?

Most adults can easily take senna because being an herbal supplement it is considered as safe. If a child under 6 years of age, you should not give them senna, without the approval of the doctor. Senna can be unfit for some individuals, therefore, you must tell your doctor about mentioned below symptoms in order to be sure about the safety of senna. Let your doctor know if you have:

  • Had an allergic reaction to senna or any other medications in your past
  • A bowel obstruction
  • Appendicitis

What are the doses of senna?

Senna should be taken once a day before sleep. You can also take senna with or without food. The normal dose of senna tablet for treating constipation is:

  • 1-2 tablets – for adults and children (aged 12 years)
  • 1 tablet – Children aged 6 years to 11 years (at bedtime)

Senna syrup dose for constipation:

  • 5ml (1-2 tsp) – Children aged 6 years to 11 years (at bedtime)
  • Half to 1 tsp – Children aged 2 to 5 years at bedtime and that is also under medical supervision

There is a plastic cup or spoon is given inside the pack of senna syrup. You should use the plastic spoon in order to give the right quantities. It is usually recommended to take the senna at bedtime because senna takes 8 hours to work, and it is given in night so that it can work overnight.

You should take plenty of water or fluids, while you are on senna, or it can worsen your constipation. Water will help to keep the stool loose and make it come out of the body easily.

Is senna beneficial in weight loss?

It may cause constipation if you use senna tea to help with weight loss. When people start using senna for weight loss, they use it for long time to get more results, which can make them dependent on laxatives or even dehydrate them.

Using excessive senna can lead to senna overdose and can show symptoms such as diarrhea, bloody stools, and pain in abdomen or even cause you to collapse. Therefore you should use this medication in moderate doses and that too after proper recommendation of doctor.

What are the precautions that I should take while using senna?

If you are allergic to senna, tell your doctor and pharmacist about it, and also if you have any other allergies. The inactive ingredients present in senna can also cause some allergic reactions which should be discussed with doctor or pharmacist.

You medical history such as appendicitis, symptoms of appendicitis for example nausea, vomiting, sudden abdominal pain, abdominal pain that is very sharp and does not go away easily, change in bowel habits (which lasts for more than 15 days), bleeding from rectum, and intestinal blockage should be checked and should be discussed with your doctor or pharmacist.

Tell your doctor about all the medications (prescription and non-prescription) or products that you use, if you are undergoing any surgery soon. If you have a condition like diabetes, or any illness that requires limitation of sugar in your diet, you should use the chewable tablet or dissolving strips with caution because such form of medications may contain sugar. For more information, you can talk to your doctor or pharmacist about the safety of this medication.

What are some other drugs that affect senna?

If you take some other drugs at the same time you are taking senna, the effect of senna can get changed. This can even increase your risk for serious side effects or can cause your other medications to not work correctly. There are some interactions that may not always occur but are possible.

If you are using some medications (listed below), talk to your doctor before taking senna. And let him know that you already using such medications, can it interact with senna? Those drugs are:

  • Digoxin
  • Diuretics (furosemide or chlorthalidone)
  • Warfarin (also called blood thinner, namely Coumadin, Jantoven)

There are many other drugs that can also interact with senna and are not listed here. You should tell your healthcare provider regarding the medications that you use. Let him know if you are using over the counter medications, herbal products, vitamins, or other prescription drugs.

It will help your doctor to decode right dose or the right alternative of senna for you. You should also not start a new medication without your doctor’s approval.

Can senna be taken together with birth control pills?

Caution is advised while taking senna and birth control pills or contraceptive pills are taken together. Ask your doctor before taking this combination. Some birth control pills contain ethinyl estradiol (a form of estrogen), and its absorption can be reduced by senna.

Senna can decrease the effectiveness of birth control pills by halting their absorption; therefore one should avoid taking this combination or should take only after approval of your doctor. Taking senna might decrease the effects of hormone replacement therapy also, therefore the concurrent administration of these two (senna and estrogens) should also be avoided.

Can senna be taken together with digoxin?

The combination of senna and digoxin also shows moderate interaction, therefore, precaution is advised while taking this medicine. Stimulant laxatives are the drugs that reduce the potassium levels in the body and senna is one such stimulant laxative. Hence it can reduce the potassium level, which can increase the risk of side effects of digoxin.

Can senna be taken together with warfarin?

You should be cautious while using the senna and warfarin together. Senna is a laxative and can cause diarrhea. You should not take an excessive amount of Senna if you take warfarin because senna can cause diarrhea and diarrhea can increase the effects of warfarin and thereby enhances the risk of bleeding. Therefore caution is advised while taking this combination.

Can senna be taken together with diuretics?

You should be cautious while taking the combination of senna and diuretics. Concurrent administration of senna and diuretic can lower the potassium level of the body to a great extent, because of synergistic effects.

Senna, being a laxative can reduce the potassium levels in the body and also diuretics (water pills) can also reduce the potassium level in the body, therefore concurrent administration of these two is not advisable. Some diuretics that decrease the potassium levels are chlorthalidone, furosemide, hydrochlorothiazide, and chlorothiazide.

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