Veggie Blog

Slimming teas, dieter’s teas and other “cleansing” products are sold in many stores, and they often seem natural and gentle. But most of them work in one way only: they are laxatives. Using laxatives to lose weight does not remove fat, and it can do real harm. This post explains why.

What is in slimming tea?

Many of these teas contain plant ingredients that are laxatives, such as senna, aloe, cascara, rhubarb root and buckthorn, and sometimes castor oil. They have been used for centuries to treat constipation. They are not tea in the usual sense, and the label may describe them as a “natural bowel cleanse” or a “detox” and avoid the word laxative. The calories in the cup are close to zero unless the tea is sweetened, so any effect on the scale comes from the laxative. In 2002 the FDA ruled that aloe and cascara sagrada could no longer be sold as ingredients of non-prescription laxative products in the United States, because the safety data the agency asked for had not been submitted.

Do laxatives make you lose fat?

No. The food you eat is digested and absorbed mostly in the small intestine, and laxatives act on the large intestine afterward. In a small 1983 study of seven women, two with bulimia who used laxatives for weight control and five healthy young women, researchers measured calorie absorption and found that even extreme purging, which produced 4 to 6 liters of diarrhea, cut the calories absorbed by only about 12 percent of intake. You can read the study abstract on PubMed. The lower number on the scale after a laxative is mostly water and it returns when you drink, which is why the National Eating Disorders Association calls the idea that laxatives control weight a myth.

What are the risks?

Repeated use can cause dehydration, an imbalance of the body’s minerals such as potassium and sodium, stomach cramps, nausea and fainting. A mineral imbalance can affect the heart and muscles. The body can also come to depend on laxatives, so that the bowel stops responding to normal doses and constipation gets worse. The National Eating Disorders Association lists severe dehydration, electrolyte disturbances, laxative dependence and damage to internal organs among the consequences of misuse. Women who are pregnant or trying to conceive should not take laxatives or herbal laxative teas without asking their doctor.

Who should be especially careful?

Laxative misuse is common among people who have, or are at risk of, an eating disorder. If you find that you are using laxatives to “make up” for eating, or you feel anxious when you cannot, please talk to a doctor or a mental health professional. Treatment works, and you do not have to manage it alone. Anyone who uses laxatives regularly for constipation should also see a doctor to find out why.

What works instead?

If you want to lose weight, the safest approach is a slow one: reduce portions a little, eat more vegetables, beans and whole grains, move more, and sleep enough. For constipation, fiber, fluids and exercise are better first steps than a laxative tea. For more on products that promise quick fixes, see our posts on diet pills and who should avoid them, herbal weight loss and eight habits for losing weight the healthy way. If a product promises easy weight loss with no effort, it is wise to leave it on the shelf.