What to Know About Taking Laxatives to Lose Weight

Some people use laxatives to lose weight. While laxatives can help you with constipation, using laxatives for weight loss is dangerous and can make you sick.

What Are Laxatives?

Laxatives are medicines for constipation. Your doctor usually only recommends these if you have problems passing stool, and only after you make changes like eating more fiber, exercising regularly, and drinking more water. 

There are five types of laxatives, and they act on your intestines in different ways.

Bulk-forming laxatives. These add soluble fiber to your stool. Soluble fiber breaks down easily in water and becomes a gel, which helps your colon hold onto water. This can soften your stool and help you pass it easier.

Stool softeners. These laxatives help mix water in with the stool so that it becomes soft enough to pass.

Lubricant laxatives. These types coat your stool and make it slippery so that it can pass out easily. These are sometimes called glycerine suppositories

Stimulant laxatives . These make the muscles in your intestines squeeze and move the stool along. Stimulants can be harsh on your body and can cause cramping.

Osmotic laxatives. These pull water from the rest of your body into your bowel and help it hold onto water. This softens your stool and helps you pass it easily.

Taking Laxatives to Lose Weight

Sometimes people think that laxatives will help move their food through their body before the body absorbs any calories. So they may take laxatives after eating a big meal or binge eating. They think this helps lose weight or will stop them from gaining weight.

This is not true. Laxatives don’t stop your body from absorbing calories or from gaining weight. The food you eat goes through lots of processes before it reaches your bowel and becomes stool. 

Your body absorbs calories, fat, and most nutrients before they get to the large intestine. What’s left of your food is waste that your body doesn’t need and that is mostly full of water and some minerals. The waste moves into your large intestine, where your body absorbs some of the water, minerals, and any other healthful substances that remain. 

So if you use laxatives and you lose weight, you are just losing water. As soon as you drink something, you will gain the weight back. 

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Side Effects of Taking Laxatives for Weight Loss

Taking laxatives for weight loss, for long periods of time, and when you don’t need them can cause problems. 

Dehydration. Laxatives make you lose water. This can cause:

  • Lightheadedness
  • Dizziness
  • Weakness
  • Confusion
  • Headaches
  • Dark-colored pee
  • Fainting
  • Blurry eyesight

Sometimes people who abuse laxatives also don’t drink any fluids, and this can be serious. In extreme cases, dehydration can cause heart problems, kidney failure, and even death.

Electrolyte imbalance. You absorb important minerals and salts called electrolytes in your colon. These are important for your muscles and nerves in your heart and your colon. Electrolyte loss can cause:

  • Heart problems
  • Muscle weakness
  • Nausea
  • Throwing up
  • Diarrhea
  • Headaches
  • Confusion

Constipation and diarrhea. Using laxatives for longer than one week can cause loss of bowel muscle tone. Because your muscles become weak, you may have trouble passing stool on your own. Laxatives can cause long-term constipation, but they can cause diarrhea too. 

Damage. Using laxatives too often and for too long can damage your intestines. This can lead to a greater chance of having colon cancer

Medications. Taking laxatives can stop your prescription medications from working properly. This can cause serious health problems. 

Eating disorder. People who use laxatives to lose weight are more likely to get an eating disorder.   

Other side effects. Laxatives can cause other serious problems in your digestive tract. If you bleed from your rectum or take laxatives and don’t have any bowel movements, you should see your doctor right away. 

How to Lose Weight Safely

Talk to your doctor about whether you need to lose weight. Sometimes you may feel you need to be thinner when you really don’t need to be. If you have a risk for heart problems and diabetes, you may need to lose weight. But using diet pills and laxatives is not a safe way to manage your weight. 

You can lose weight safely. Some tips include:

  • Getting regular exercise
  • Eating lots of fruits and vegetables
  • Drinking less sugary drinks than soda and alcohol
  • Swapping snacks for healthier versions
  • Eating fewer calories

If you have an eating disorder, it’s important to talk to your doctor about your weight and your habits. If you’re thinking about starting laxatives to lose weight, you should also talk to your doctor. This may be a sign that you should see a counselor. 

WebMD Medical Reference Reviewed by Dan Brennan, MD on April 30, 2021

Sources

SOURCES:

American Journal of Public Health: “Diet Pill and Laxative Use for Weight Control and Subsequent Incident Eating Disorder in US Young Women: 2001-2016.”

Family Doctor: “Laxatives: OTC Products for Constipation.”

Kelty Eating Disorders: “Dangerous Eating Behaviors.”

National Eating Disorders Association: “Laxative Abuse.”

NHS: “12 tips to help you lose weight,” “Laxatives,” “Obesity.”

Rady Children’s Hospital San Diego: “Digestive System.”

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