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Overview: Senna is a stimulant laxative used to help you poop if you are having trouble with occasional constipation. Common side effects may include nausea, diarrhea, stomach pain, and a change in the color of your pee. You should not take senna for more than 1 week unless your health care provider tells you to do so. Senna comes in various forms, including a chewable tablet, capsule, liquid, or tablet that you take by mouth.

Uses

What is senna used for?

Senna is commonly used to help you poop if you have occasional constipation.

Senna may also be used for other conditions as determined by your health care provider.

How does senna work (mechanism of action)?

Senna is a stimulant laxative. It works to help constipation by stimulating the muscles of the intestines, which increases the movement of poop through your intestines and out of your body.

How is senna supplied (dosage forms)?

Brands and other names

  • Ex-Lax
  • Geri-Kot
  • Senokot

Example dosage forms and strengths

  • 15 mg chewable tablets
  • 8.3 mg, 8.6 mg, 17.2 mg oral capsules
  • 8.8 mg/5 mL, 25 mg/15 mL oral liquid
  • 8.6 mg, 15 mg, 17.2 mg, 25 mg oral tablets

How should I store senna?

Storage requirements may vary among senna products. Senna should generally be stored at room temperature. Follow the storage instructions on your specific product. If there are no storage instructions, most medicines should be kept in a cool, dry location that is out of reach of children and pets and not in direct sunlight. If you are unsure how to store your product, ask your pharmacist.

Side Effects

What are the most common side effects of senna?

The most common side effects of senna are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Stomach pain or cramping
  • Diarrhea
  • Nausea
  • Change in the color of your pee, such as to yellow-brown

There may be other side effects of senna that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of senna?

While less common, the most serious side effects of senna are described below, along with what to do if they happen.

Severe Allergic Reactions. Senna may cause allergic reactions, which can be serious. Stop taking senna and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use senna?

Allergies to Ingredients. People who are allergic to any of the following should not take senna.

  • Ex-Lax
  • Geri-Kot
  • Senna
  • Senokot
  • Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific senna products they stock.

Digestive Tract Problems. Tell your health care provider if you have constipation with stomach pain, nausea, or vomiting. These could be symptoms of a more serious condition. Senna should not be taken if you have certain stomach problems, including a gut blockage or tear, ulcerative colitis, Crohn’s disease, appendicitis, poop stuck in your digestive tract (fecal impaction), bleeding in your digestive tract or rectal bleeding, or blood in your poop. 

What should I know about senna before using it?

There are multiple forms of senna available. Read and follow the instructions for the product you have and make sure you understand how to take it properly. Do not take more than the recommended dose. If you have any questions, talk to your health care provider.

Keep senna out of the reach of children.

Senna usually makes you poop in 6-12 hours after taking it. 

You should not take senna for more than one week unless your health care provider tells you to do so. 

Stop taking senna and contact your health care provider right away if you have rectal bleeding, blood in your poop, or if you are not able to poop after using the medicine. These could be symptoms of a serious condition.

Senna may affect how other medicines work. You may need to take senna at a different time than other medicines. Your health care provider can let you know when to take each medicine.

Some senna products should not be chewed, cut, or crushed. Some senna products should be chewed before swallowing. Check the product label and ask your pharmacist if you are not sure.

If you are taking senna liquid, shake it well before each dose. Use an accurate measuring device to measure your dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist what measuring device to use.

What should I tell my health care provider before using senna?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if senna is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

Low-Sodium Diet. Some senna products contain sodium. If you follow a low-sodium (low-salt) diet, ask your health care provider whether you should avoid certain senna products.

Other Medicines and Supplements. Senna may interact with other medicines and supplements. Before taking senna, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how senna could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will let you know if you should take senna while you are pregnant or trying to get pregnant.

Breastfeeding. Senna may pass into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should take senna while breastfeeding.

Interactions

Does senna interact with foods or drinks?

There are no known interactions between senna and foods or drinks.

It is unknown if drinking alcohol will affect senna.

Does senna interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking senna.

  • Deflazacort (Emflaza, Jaythari), which is a medicine used to treat Duchenne muscular dystrophy (DMD)
  • Dichlorphenamide (Keveyis, Ormalvi), which is a medicine used to treat a rare inherited condition called primary periodic paralysis (PPP)
  • Digoxin (Lanoxin), which is a medicine used to treat irregular heartbeat and some types of heart failure
  • Lily-of-the-valley, which is a supplement that may be used for certain heart problems
  • A laxative to clean out your bowel (bowel prep), such as before a colonoscopy

Senna may affect how well some other medicines work. Tell your health care provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with senna. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much senna?

If you or someone else has used too much senna, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of senna?

Senna is meant to be taken only when needed. Take it according to the product label or as your health care provider recommends. Do not take double or extra doses.