Laxative for weight loss: the wrong idea

[Article updated on 19/09/2023]

Laxatives are medications that accelerate intestinal transit and soften stools to facilitate their evacuation. Also available in the form of dietary supplement or food, they are recommended to relieve constipation. They are, therefore, used in a medical context. But, some people consider laxatives as suitable ways to lose weight. This misuse of using a laxative to lose weight turns out to be an unhealthy method associated with numerous side effects. It is not wise to use laxatives for weight loss, because this use can have harmful consequences or more or less serious damage to your health.

Before reading on

I’m not an expert in this field, but I am passionate about nutrition and health.

The articles you’ll find on my site are the result of in-depth research that I’d like to share with you. However, I would like to stress that I am not a health professional and that my advice should in no way replace that of a qualified physician. I’m here to guide you, but it’s important that you consult a professional for specific questions or medical concerns. Your well-being is important. So be sure to consult the appropriate experts and take the best possible care of yourself.

Laxatives, what are they for?

Laxatives, pharmaceutical or not, are intended for the treatment of constipation. This is a type of medication or herbal tea that is used when there is difficulty passing stools in a subject. Thus, a laxative helps overcome the signs linked to this digestive disorder which is marked by hard, dry stools that are difficult to pass. The frequency of stools is disturbed with less than 3 stools per week, for several weeks. Constipation can also be accompanied by pain in the stomach, bloating, heaviness in the lower abdomen, pain during defecation. , flatulence and abdominal cramps. Laxatives help alleviate, or even eradicate, these discomforts and unpleasant symptoms caused by constipation, while allowing you to get rid of this digestive disorder.

The effectiveness of laxatives thus softens and triggers the passing of stools. This is why a plant-based laxative or not is prescribed in a medical setting when there is a scarcity of stools, the presence of hard stools, incomplete expulsion of stools and/or difficult defecation. Laxatives are therefore used to treat constipation and are recommended for:

  • accelerate the movement of the intestines,
  • help empty (purge) the intestines,
  • help digestion in case of constipation,
  • facilitate the evacuation of stools.
Laxatives make it easier to pass stools
Laxatives make it easier to pass stools

How do laxatives work?

The operating principle differs depending on the active ingredient that characterizes them and is very specific to each type of laxative. Generally, there are several types of laxatives:

  • Osmotic laxatives: they attract water to the stools in order to increase their volume, make them softer and facilitate their natural elimination.
  • Stimulating laxatives: they stimulate intestinal movements, increase intestinal motility and intestinal transit by irritating the mucous membrane, thus facilitating the evacuation of stools.
  • Lubricating laxatives: they lubricate the stools, soften them and facilitate their evacuation.
  • Bulk laxatives: they help to increase the volume of the fecal mass and make the stools soft, which will trigger peristalsis of the intestines and facilitate the elimination of fecal matter.
  • Rectal laxatives: they act by promoting the expulsion of stools by contraction of the rectum. Thus they promote the evacuation of stools.

These different mechanisms of action have the same purpose, to facilitate and accelerate defecation. Thus, laxatives make it possible to evacuate stools that stagnate in the colon (transit constipation) or in the rectum (terminal constipation). One of the possible side effects associated with most of these different laxatives is diarrhea, especially in case of overdose or inappropriate use.

Do laxatives make you lose weight?

Some people think they can use a laxative to lose weight. Others recommend them to help with weight loss. Thus, people venture to experiment with the use of a laxative as a quick solution to lose weight. To do this, they do not hesitate to abuse laxatives.

Indeed, taking laxatives in large and regular quantities can increase the frequency of stools and induce diarrhea.

These various laxative doses soften the stools, which are thus waterlogged, while facilitating their evacuation. This diarrhea, associated with a significant loss of water, is sometimes compared (wrongly) to weight loss.

But, in fact, the weight loss observed on a scale after the use of laxatives is, in reality, a loss of water and intestinal contents, in particular, feces, mineral salts, etc. Which gives you the impression of losing weight by passing out more fecal matter and eliminating a significant amount of water.

Thus, laxatives can only cause temporary loss of water weight and are not an effective method of long-term weight loss. Since you are going to drink water again, then the water loss will quickly be replenished.

Also, with the use of laxatives, no fat accumulated in the tissues is eliminated. Thus, the body does not shed excess fat, since laxatives do not melt fat.

Obviously, laxatives do not help with weight loss, because by the time laxatives work in the large intestine and empty it, the calories consumed are already absorbed by the small intestine and are, therefore, in the blood. . The idea that laxatives make you lose weight turns out to be incorrect.

What are the harmful effects of using laxatives to lose weight?

  • Using a laxative to lose weight can lead to dehydration

Excessive use of laxatives to lose weight leads to water loss. Indeed, some laxatives act by drawing water into the intestines and stools, inducing water loss through the passing of stools. When this water loss is not replenished in time, it causes dehydration which can be harmful or potentially dangerous. This lack of water in the body will cause a feeling of thirst, but also a loss of energy, a reduction in urine production, and dry skin and lips. Headaches, dizziness, vision loss, and dizziness may occur as dehydration worsens. This worsening can lead to the death of the patient.

Laxatives can cause dehydration
Overuse of laxatives can cause dehydration
  • Using a laxative for weight loss can lead to an electrolyte imbalance

Sodium, potassium, calcium and phosphorus are mineral salts or electrolytes found in the body.

“Some of these laxatives can cause an electrolyte imbalance because they remove nutrients and other substances with the water. »(1)

Excessive use of laxatives will lead to the elimination of a good number of mineral salts necessary for the proper functioning of the body. Over time, the loss of these salts will cause an electrolyte imbalance with consequent health problems. The subject may be affected by breathing difficulties, leg cramps, irregular heartbeat, muscle fatigue, muscle pain. In the most severe cases, this imbalance can lead to coma, cardiac arrest and ultimately death.

  • Using a laxative to lose weight can cause disruption of the intestinal microflora

All the bacteria and fungi present in the intestine and digestive tract constitute the intestinal flora. The latter helps neutralize harmful bacteria, harmful bacteria that enter the body through food. The intestinal flora eliminates bacteria and prevents them from affecting the body. Taking laxative substances to lose weight, in large quantities and over the long term, can cause an imbalance in the intestinal flora. These substances are likely to damage the intestinal flora, with a significant reduction in the good bacteria associated with good immune health. This abusive use induces an expulsion of bacteria necessary for the mucous membranes and the proper functioning of the intestine.

Thus, this disruption of the balance of the intestinal flora can lead to a weakening of the immune system, a deterioration of digestion, meteorism, severe colitis, or even death.

Intestinal flora
Beware of disturbances in the intestinal flora!

Why shouldn’t you use a laxative to lose weight?

Laxatives are not harmless. Misused, as is the case when used for weight loss, they can cause multiple side effects.

Indeed, “…the abuse of certain laxatives represents a health risk”(2).

Overuse of laxatives to lose weight can be dangerous for intestinal health, with a reduction in intestinal function, intestinal paralysis, serious dysfunction of intestinal motility, the occurrence of irritable bowel syndrome, sluggish intestines. .

Also, excessive use of a laxative to lose weight can lead to uncontrollable diarrhea, stomach ulcers and abdominal pain. Abuse of laxatives can expose you to risks related to an intestinal tumor, loss of ability to function of the colon, colon infection, hemorrhoidal attacks, colic, and even cancer of the colon. colon. The harmful effects of excessive use of laxatives for weight loss also include kidney failure, pancreatitis, stomach cramps and rectal burning.

Excessive consumption of laxatives can lead to hormonal imbalance and a drop in blood pressure.

Using laxatives for a long time can increase the risk of laxative dependence.

“However, we must not forget that it is relatively easy to develop a dependence on laxatives…”(3).

The body gets used to laxatives and demands more of them over time, so laxative sickness can occur. This pathology manifests itself when you abuse laxatives or use them improperly, for example, for weight loss. It can cause excessively loose stools and excessive frequency of them (diarrhea).

Here is my little video on the subject:


(1) Alan Low: Treating constipation with laxatives

(2) Julie Luong: Constipation: MediaPedia,

(3) Suren Bahidsky: The dangers of laxatives | How to avoid addiction? March 2018