Gut health trends on Tiktok such as #guttok have been responsible for spreading myths such as laxatives help with weight loss. This is completely inaccurate, and may even harm your health.

As an IBS nutritionist I sometimes recommend people use laxatives for constipation, but there is no evidence they can support weight loss. And misusing them can be dangerous.

The Misconception: Laxatives help with weight loss

The TikTok trend promoting laxatives for weight loss has gained traction, primarily because people are suggesting it’s an easy and inexpensive way to lose weight quickly.

Some even claim it’s similar to the effects of prescription medications like Ozempic. However, this is far from the truth, and here’s why:

1. Laxatives Are Not Designed for Weight Loss – and do not work! 

Laxatives are intended to relieve constipation by promoting bowel movements. There are different types of laxatives that can be chosen dependent on the patient’s diets, age, digestive symptoms and other health conditions. 

Miralax (the one most mentioned on TikTok) is Polyethyline glycine (PEG) which is an osmotic laxative. In the UK brands include Movicol, Macrogol 3350, and Moviprep.

These types of laxatives draw water into the bowel, helping to form a softer stool. You need to be well hydrated with this type of medication, to allow the water to be drawn into the intestines. 

Other laxatives (like ispaghula husk / Fibrogel) may provide more bulk to stimulate a bowel movement, or may stimulate the colon to contract (e.g. products containing senna). 

Laxatives of any kind do not reduce or remove fat cells or reduce energy intakeThere is no evidence that laxatives lead to fat loss.

How laxatives affect your body

Most nutrients, such as fats, are absorbed in your small intestine, before the stool gets to the large bowel.
Laxatives stimulate the large intestine, so in most cases you’re not pooing out the food you just ate. But instead you’re removing the day before yesterday’s dinner.
Osmotic laxatives may take a day or two to work, and some people feel a little bloated for a day. Stimulant laxatives, such as senna, may get to work a little quicker. 
But this doesn’t really reduce caloric absorption just because you’re getting a faster reaction to the medication.
Your food stays in the digestive tract from around 24-48 hours.

When you start to poo

Any initial weight loss is due to water and waste elimination, not fat reduction. As soon as you rehydrate and replenish your body, the lost weight will return.

If you’ve been backed up with stool when you take a laxative your stomach may feel flatter when it’s empty. However, it will start to refill as soon as you eat. It’s normal to have food in your colon. 


A white toilet in a grey bathroom. A yellow banner with the words Laxative abuse can be dangerous.

2. Health Risks Of Laxative Abuse

Using laxatives for weight loss can lead to a host of health problems, including electrolyte imbalances, dehydration, nutrient deficiencies, and damage to your digestive system.

It can also cause a dangerous cycle of dependency, as your body may become reliant on laxatives to have regular bowel movements.

When waste products make their way to our large intestine, our body gets to work reabsorbing electrolytes and fluids. It’s like a recycling project inside us, where our body tries to salvage as many nutrients as it can before saying goodbye to the stuff we don’t need – and that’s what ends up in our poo.

If you skip this important step, it can really affect your health.

You could become dehydrated, lose too many electrolytes, and start feeling all kinds of strange things – like dizzy spells, low blood pressure, and feeling super tired.

Plus, you might ironically find it harder to get up and move around, which is something that can really help with managing your weight.

If you are very low on electrolytes long term you might get headaches, feel dizzy, have weak muscles, or even get heart palpitations. And if you keep this up for a long time, it could spell trouble for your gut, kidneys, and liver.

3. Short-Term Results, Long-Term Consequences

While you may see a temporary drop in the numbers on the scale, laxative use may lead to a negative changes in your gut microbiome which may affect your immune system.

Regular use (as in most days of the week) of laxatives is also associated with a higher risk of all-cause dementia, particularly in those who used multiple laxative types or osmotic laxative. This study from 2023 was on people in the UK aged 40–69 yrs.


A close up of a toilet roll with a packet of blue pills sticking out of the middle. A yellow banner with the words, Don't use laxatives for weight loss

But what about my chronic constipation?

If you’ve been prescribed laxatives for long term use, you should have regular check ups with your doctor to ensure you’re staying healthy. 

In most cases if you’ve just bought laxatives from the chemist, and you’re still not seeing any results after a week it’s work speaking to your pharmacist, or making an appointment with the doctor. 


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The Importance of a Healthy Approach

Losing weight is a common goal for many people, but it’s essential to approach it in a safe and sustainable way.


  • Balanced Nutrition: Focus on a well-rounded diet rich in fruits, vegetables, lean proteins, and whole grains. A nutrition proffessional can help you create a personalized meal plan that supports your weight loss goals while nourishing your body.

  • Regular Physical Activity: Incorporate regular exercise into your routine, as it helps boost metabolism, build muscle, and improve overall well-being. Aim for 30 minutes of movement a day, and try to find something you enjoy like dance, team games or home workouts. 

  • Consult a Healthcare Professional: If you’re struggling with weight loss or digestive issues, consult a healthcare provider or nutritionist. They can help identify any underlying issues and provide evidence-based guidance for achieving your goals.

  • Mindful Eating: Practice mindful eating techniques to better understand your body’s hunger and fullness cues. This can help you make healthier choices and avoid overeating.

In the era of viral trends and quick fixes, it’s crucial to remain grounded in science and prioritize your health.

Laxatives should never be used as a means to achieve weight loss. They come with a multitude of risks and ultimately it won’t help you lose weight! 

Instead, opt for a balanced and sustainable approach to weight management, one that supports both your physical and emotional well-being.

Contact me if you want help with IBS and losing weight. 

Hi I'm Anna Mapson, registered Nutritional Therapist.

I help people with IBS and SIBO get control of unpredictable gut symptoms to find long term relief from painful and embarrassing IBS without restrictive dieting.

I can help you to:

  • understand your digestion better, so you recognise your triggers
  • eat a well balanced diet, with tasty meals that are simple to prepare
  • develop better digestion and more energy

Find more about my 3 month 1:1 Gut Reset programme

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