Of all the health myths in the world, the idea that there is a silver bullet for weight loss may be among the most persistent and pernicious. From detox teas to trendy diets, we've seen countless products and practices that people claim are quick, easy, and harmless ways to lose weight. Using laxatives for weight loss is another one of those practices, but it’s hardly harmless. Unfortunately, this might be one of the longest running and most popular misguided methods for weight loss, especially among young women.
One study looking at 13,000 people published in the journal Pediatrics in July 2016, found that 10.5 percent of women aged 23 to 25 have used laxatives to try to lose weight. Misusing laxatives is an all-around bad idea. Here’s what you need to know about laxatives, including why you don’t ever want to use them for weight loss.
1. First things first: What are laxatives?
Laxatives are a type of medication used to treat constipation by loosening stool or encouraging bowel movements, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Nearly everyone experiences constipation at one point or another. There are approximately a zillion causes, including dietary issues (too little fiber, too much dairy), certain medications (antidepressants), lifestyle changes (not pooping when you have to go, traveling), medical conditions (hypothyroidism, IBS), and even stress. Not only does constipation feel miserable—it can cause complications like hemorrhoids or anal fissures if you strain too hard to poop.
Lifestyle modifications like eating more fiber-rich foods, exercising regularly, and drinking enough water should be your first move, as SELF previously reported. But sometimes, you might need a little extra push. This is where laxatives come in. For the occasional treatment of constipation, they can do the trick and are generally pretty harmless.
2. There are several types of laxatives.
There are actually five main types, and they all get things moving in different ways, , Marc Leavey, M.D., an internist at Baltimore's Mercy Medical Center, tells SELF. And some of them are available in both an oral form and a rectal suppository. Here is how they work, as explained by the Mayo Clinic:
- Stimulants (Dulcolax, Senokot): This class of laxatives triggers contractions of intestinal wall muscles in order to move stool along the GI tract, resulting in elimination. These are available in oral forms and as a rectal suppository.
- Osmotics (Milk of Magnesia, Miralax): They work by drawing water from nearby body tissue into the colon in order to soften the stool and spur bowel action.
- Bulking agents (Metamucil, Benefiber, Citrucel): These fiber supplements absorb liquid in the intestines and swell up to form a large, soft, bulky stool, the presence of which prompts a normal bowel movement.
- Lubricants (Fleet): These use oil, like mineral oil, to coat both the bowel and the stool, keeping the stool moist and soft and helping it pass through the GI tract more easily. These also come in rectal suppository form.
- Stool softeners (Colace, Surfak): These help reduce straining by helping moisture mix into dry, hard stools.
3. Laxatives will not help you actually lose fat.
If you try to use laxatives for weight loss, you may well see the number on the scale go down. But this apparent drop is deceiving because it’s actually water weight that you’re losing, women’s health expert Jennifer Wider, M.D., tells SELF. The weight loss is temporary and is not actually changing your body fat composition. “Very little to no fat can be lost [with laxatives],” Dr. Wider explains..
While weight and weight loss are highly individual and complex issues, what’s clear is that they depend on a number of factors in and out of your control. This includes your diet and exercise routine, yes, but also things like your metabolism, hormones, genetics, other health issues you have going on, or medications you’re taking. In any case, as Dr. Leavey puts it,your body weight has to do with so much more than "excess poop.”
4. Long-term use of laxatives can actually perpetuate your constipation issues.
Stimulant laxatives, the kind most commonly used for weight loss, are “relatively harsh” and shouldn’t be used for a long period of time, says Dr. Leavey. Why? “The bowel can get used to them, leading to more constipation,” he explains. Your system develops a dependence on them, according to the Mayo Clinic, meaning your ability to have natural bowel movements declines and need more and more laxatives. It’s a nasty cycle best avoided. (That said, if you do think you have developed a dependence on laxatives, talk to your doctor.) According to the NIDDK, you should only use stimulant laxatives if your constipation is severe or other laxatives have not helped.
While of course, if you are experiencing persistent constipation, you should talk to your doctor first to see if there’s an underlying health issue, generally bulk-forming laxatives are the gentlest on your body and safest to use long term, according to the Mayo Clinic.
5. When used over the long-term, laxatives can actually be extremely harmful.
While it’s usually fine to take a laxative here and there if you’re stopped up, ongoing and unnecessary laxative use—such as using them in an attempt to lose weight—can negatively impact your health in a few ways.
Prolonged laxative use can irritate the lining of your bowel and cause all sorts of gastrointestinal issues, Dr. Leavey says. It can also cause dehydration and electrolyte and mineral imbalances, Dr. Wider says. Since electrolytes such as calcium and sodium are crucial to several body functions, an imbalance can cause dizziness, fainting, blurry vision, and even death, Dr. Wider explains. These imbalances can also cause symptoms like abnormal heart rhythms, weakness, confusion and seizures, per the Mayo Clinic.
What’s more, osmotic laxatives can cause your blood pressure to drop and even cause permanent kidney damage, Dr. Leavey adds. Bottom line: This is not a weight-loss method you want to try. “There is no rational basis to try to lose weight with laxatives, and there is a clear potential for harmful side effects,” says Dr. Leavey. “Don’t do it.”