Are laxatives for weight loss safe?

Key Takeaways

• Laxatives are designed for constipation, not weight loss, and can lead to serious side effects and dangerous complications when used incorrectly.
• When you lose weight on laxatives, it's from water weight and stool, not body fat. This weight loss is temporary, and you'll likely regain the pounds once you rehydrate your body. 

The use of laxatives for weight loss is one of those diet fads that never seem to go away. They've been touted by celebrities, on TV, and in film as a way to lose weight. Now, they're trending on TikTok, with users hailing laxatives as "budget Ozempic," the diabetes medication that's also used off-label for weight loss. 

The truth is that laxatives won't help to lose weight. But there are safer, proven options for weight loss that can actually work. Read on as Ro breaks down how laxatives work, the risks of using them for weight loss, and what to do instead.

What Are Laxatives?

Laxatives are usually over-the-counter medications designed to help those dealing with constipation and having trouble with bowel movements. Usually, laxatives are a consideration after lifestyle changes to relieve constipation, like taking up a regular exercise routine and increasing fiber or water intake, have already been tried. Laxatives work in many different ways depending on what type of laxative they are. Some laxatives require a prescription, while others can be over-the-counter. 

There are many different types of laxatives, with the main types including:

• Bulk-forming laxatives: These are medications such as Metamucil (psyllium) that add bulk to stool, making it larger and softer by increasing the water content. This allows the stool to pass more easily through the colon.
• Stool softener laxatives: Colace (docusate sodium) works in a different way by making it easier for water and lipids to penetrate the stool, softening it in its own way. 
• Osmotic laxatives: Products such as Miralax (polyethylene glycol) pull water from other parts of the body and into the colon. This extra water adds volume and pressure, which can make it easier to have bowel movements.
• Lubricant laxatives: These are solutions such as mineral oil that coat and lubricate stool and intestine. The slippery surface makes stool easier to pass. 
• Stimulant laxatives: Dulcolax (bisacodyl) stimulates intestinal muscles, causing them to contract and move the stool through the digestive tract.

Different laxatives can work better for different people. If you're pregnant or have any health conditions, it's a good idea to ask your healthcare provider which laxative (if any) they recommend. While laxatives are generally safe when used as directed, different ones can cause potentially serious side effects for people with certain health conditions.

Can Laxatives Help You Lose Weight?

The idea that laxatives can help with weight loss is a myth that has persisted in popular culture due to a misunderstanding of how laxatives work. Because laxatives help stimulate a bowel movement, some people think they speed up how quickly food moves through the body. The myth is that when food moves quickly, the body doesn't have a chance to absorb as many calories before it gets passed through the GI tract, thus leading to weight loss. 

But that's not how laxatives work. Laxatives affect the stool and the large intestine, not the stomach or small intestine, where food gets digested. The body starts to absorb calories from food well before it reaches the large intestine, which is where the laxatives work their magic. By the time food reaches the large intestine, it's mostly waste matter. The body will continue absorbing some water and any remaining electrolytes on its way out, but the "weight" lost on laxatives is primarily water weight and stool—not significant amounts of body fat. So, after drinking water, the weight will return.

Risks of Using Laxatives for Weight Loss

When taken as directed on an occasional basis, laxatives can reliably relieve constipation. However, there may be some short-term side effects, such as diarrhea, nausea, bloating, vomiting, or stomach pain. Normally, these are manageable, but if used for weight loss, the side effects of laxatives can get more serious. 

Once food enters the large intestine, it absorbs the last remaining valuable bits of the waste matter: namely, water and electrolytes. However, since laxatives speed up this process, they can cause dehydration and electrolyte imbalances. If you're not rehydrating or eating well, this can lead to symptoms like:

• Dizziness
• Fainting or lightheadedness
• Weakness
• Confusion
• Headaches
• Nausea
• Vomiting
• Diarrhea 
• Heart palpitations
• Reduced urination or dark urine

Taking laxatives on a longer-term basis can make it difficult to have a bowel movement without using them, so this may result in a vicious cycle of chronic constipation where a person becomes dependent on laxatives to poop. It can even create physical changes in the intestine, flattening the folds that help move stool through your colon and absorb nutrients along the way. Long-term laxative abuse can create potassium deficiencies, kidney damage, and heart problems that can become dangerous and significantly damage the body.  

Taking laxatives for weight loss is on the spectrum of disordered eating behaviors. In one study of teens and young adults, those who took laxatives for weight loss were almost three times more likely to develop an eating disorder within the next five years. Other studies have found that the eating disorder may develop even sooner—within the next one to three years.

How to Lose Weight Safely 

Higher body weight can increase the risk for certain health conditions, including diabetes and heart disease. In these situations, healthcare providers may recommend weight loss. A healthcare provider can help patients understand if weight loss is a good idea for them and recommend an appropriate treatment plan. If a person is struggling with body image and self-worth, a mental health professional can help.

Laxatives aren't the way to lose weight. Instead, try these approaches to lose weight safely and sustainably:

• Exercise regularly. Regular physical activity can help with weight loss and weight maintenance. For the best results, aim to exercise at a moderate level for at least 30 minutes per day, three times per week, and adopt a mix of resistance and aerobic-based workouts. 
• Improve your diet. Calories in vs. calories out play the largest role in weight loss (or gain).  Beyond eating less, eating the right types of foods can also help with weight loss by making people feel more full. Eat more fruits, vegetables, and fiber-rich foods that boost feelings of fullness. Protein is another good one to focus on to curb hunger pangs. Avoid empty calories where you can. Limit soda and alcohol, and reach for healthier snacks. 
• Weight loss medications. Certain drugs can also help with weight loss when combined with diet and exercise. Ask your healthcare provider about GLP-1s like Wegovy (semaglutide), Saxenda (liraglutide), or Zepbound (tirzepatide), depending on the indication. There are also prescription weight loss pills like Qsymia (phentermine/topiramate) and Contrave (bupropion/naltrexone)

Bottom Line on Laxatives for Weight Loss

Laxatives are not a safe, effective, or long-lasting way to lose weight. They can cause uncomfortable, and potentially dangerous, side effects when used on a long-term basis, and the only weight lost is water and stool. Instead, talk to your healthcare provider about a weight loss plan that includes diet, exercise, and, if appropriate, medication.