What is senna and does it help with weight loss?

Dear Reader, 

You ask a great question about senna! Senna is a laxative, and as a result, can help people lose water weight. As you note, it’s commonly found in diet teas that claim to aid in weight loss. However, senna may be harmful to people who have certain medical conditions like heart or kidney disease. Current guidance also states that using senna for long periods of time could have unintended consequences such as colon cancer. Senna has some medical purposes, but if you’re thinking of using it simply to lose weight, there may be options that are more sustainable. 

Senna is a sweet and bitter tasting medicinal plant. While this ingredient has been approved by the Food and Drug Administration (FDA) as a natural laxative, chemicals in senna called sennosides have been known to cause the muscles in the intestine to contract by irritating the bowel lining. This leads to more frequent and larger bowel movements. As such, weight loss from senna occurs due to the loss of water weight, and does not in fact help a person shed fat or reduce the calories that are absorbed from their food. 

In some cases, people may use senna to empty the bowels prior to a diagnostic test like a colonoscopy. Others may use it to help with irritable bowel syndrome (IBS) or hemorrhoids. However, the efficacy of senna used in these ways is unclear. In addition to influencing bowel movements, there are some other health benefits that people may choose to use senna for. Research shows that senna is rich in antioxidants, improves cholesterol and blood sugar, and can protect the liver from damage.  

Even though the FDA has approved senna use, some people may not be able to use senna without harmful effects. Some of these side effects include:  

• Liver issues 
• Electrolyte imbalance 
• General weakness 
• Altered brain function, such as confusion and memory loss 
• Abdominal discomfort 
• Stomach cramps 
• Diarrhea 
• Nausea 
• Vomiting 
• Bloating  

Senna often comes in the form of a dietary supplement. While the ingredient itself has been approved, the FDA doesn’t evaluate every dietary supplement with senna. Dietary supplements aren’t under the same regulations as drugs, so they don’t require the same approval process. This means whoever makes the supplement is responsible for the drug safety. The FDA will only intervene if the products are unsafe or mislabeled. If you’re considering taking senna, you may want to learn more about who makes your supplement. 

Senna hasn’t yet been studied for its long-term effects. However, research does show that long-term use of laxatives can weaken bowel muscle tone. This can damage the intestines, leading to long-term constipation, and can even increase the risk of colon cancer. 

If you choose to use senna, there are strategies that you may try to help reduce the long-term effects: 

• Speak with a health care provider. Before starting any new medications or supplements, it may be helpful to first speak with a health care provider to learn more about whether it’s right for you given your health history. Certain medical conditions such as pregnancy, heart conditions, kidney problems, Crohn's disease, ulcerative colitis, and more may increase your risk for more serious side effects. 
• Calculate the dosage. A standard dosage of senna is about 15 milligrams (mg), usually taken before bed. That said, it can be challenging to accurately measure tea leaves, as steeping time and temperature of the tea can affect the amount of sennosides released. If you’re concerned with difficulty measuring tea, senna can also be found in the form of a chewable tablet, liquid, or powder. 
• Watch for drug interactions. Senna may interact with drugs such as diuretics, blood thinners, steroids, and certain heart medications. Additionally, it may interact with supplements such as aloe, magnesium, and rhubarb.  
• Know the side effects. Senna may cause dehydration, which may result in dizziness, weakness, confusion, headaches, and electrolyte imbalances. These imbalances may lead to further effects, such as heart concerns, muscle weakness, diarrhea, and vomiting. 

If you’re more interested in the weight loss aspect of senna, there may be other alternative methods for you to try that don’t involve diet teas. These methods can include:  

• Swapping snacks for more nutritious versions.  
• Getting a full night’s rest.  
• Adding more physical activity to your lifestyle, if possible. This can include walking, yoga, Pilates, dance, and more.  
• Speaking with a nutritionist, as they can help you create a dietary plan based on your individual needs.  
• Making physical activity fun by listening to music, playing sports with friends, or taking beginner classes at a local gym.  

All this to say, occasional use of senna tea may be helpful for preventing constipation, reducing water retention, and short-term weight loss. However, prolonged use of senna can cause some serious long-term effects if you’re not aware of what to look out for. For more information on alternative weight loss strategies, feel free to check out the Centers for Disease Control and Prevention’s guidelines for healthy weight, nutrition, and physical activity!