Activated charcoal is a substance that doctors use to treat certain types of poisoning. It is not a proven method of treating or preventing stomach bugs, but it may reduce diarrhea for some people.

There is little research on how effective charcoal is for reducing diarrhea, so it is still unclear whether it is a reliable or safe method of treating the symptoms of a stomach bug.

Activated charcoal also has some potential risks, such as causing vomiting and interfering with the absorption of any medications a person takes. If a person is already vomiting, this substance may make things worse.

Keep reading to learn more about using activated charcoal for a stomach bug.

A small pile of activated charcoal tablets on a table.Share on Pinterest
Liudmila Chernetska/Getty Images

Activated charcoal is a product that manufacturers make by burning wood at high temperatures to produce a residue. This residue consists of carbon. Manufacturers can turn this carbon into a powder, which some then sell as a dietary supplement.

Historically, people used charcoal as a treatment for poisonings. Doctors still use it for certain types of poisoning today. It can “soak up” some of the poison and help remove it from the body. However, it does not work in all cases.

Some companies make unproven claims about the abilities of charcoal. Although anecdotal evidence suggests that it helps with gas and bloating, claims that taking charcoal will generally “detoxify” the body are not based on science.

Learn more about charcoal and detoxification.

Activated charcoal does not cure stomach bugs. This is because stomach bugs occur due to a viral, bacterial, or parasitic infection rather than to toxins or poisoning. Charcoal cannot prevent these pathogens from multiplying and causing symptoms.

However, charcoal can potentially improve diarrhea, which is a common symptom of stomach bugs. It may do this by absorbing the fluid content of stools, making them more solid.

There is little research to prove this, though. Researchers have suggested that charcoal may be a useful antidiarrheal treatment for people in palliative care, but its effectiveness remains unclear.

Stomach bugs, or the stomach flu, often get better on their own in several days. The best treatment approach for people with stomach bugs consists of rest and hydration. By hydrating properly, people can replace the water and electrolytes lost through vomiting or diarrhea.

Activated charcoal does not prevent stomach bugs. People get the infections that cause stomach bugs through contact with contaminated food, water, or surfaces. The best way to prevent stomach bugs is through proper hygiene.

People can prevent the spread of stomach bugs by:

  • washing the hands frequently with soap and water, especially after using the bathroom or before preparing food
  • cleaning frequently touched surfaces regularly
  • washing fruits and vegetables thoroughly
  • heating foods to safe temperatures when cooking
  • staying away from people with a stomach bug

Anyone in the household who has a stomach bug should not prepare food for other people. It is also advisable to clean potentially contaminated surfaces with a mixture of 5–25 tablespoons of bleach and 1 gallon of water.

Rotavirus vaccines are effective in protecting against a certain type of stomach bug. Infants as young as 2 months can receive oral rotavirus vaccines.

Activated charcoal has some potential risks. It can cause adverse effects, such as:

  • vomiting
  • blockages in the bowel
  • pulmonary aspiration, which is when a person inhales charcoal powder into the lungs

Pulmonary aspiration can cause a lung injury known as aspiration pneumonitis. Aspiration pneumonitis can cause breathing difficulties and even death.

Some people have a higher risk of these complications than others. These individuals include those who:

  • have disorders of the intestine
  • take opioids
  • take antimuscarinic drugs, such as atropine and scopolamine
  • take multiple or high doses of activated charcoal

Charcoal is also dangerous to give to someone who is unconscious. This is because it can cause vomiting, and the person could choke on the vomit. If a person with vomiting and diarrhea becomes unconscious, it is a medical emergency.

Studies investigating the milder side effects of activated charcoal are lacking. In mice, activated charcoal can cause constipation. However, it is unclear whether this could also apply to humans.

Charcoal also absorbs liquids, which has made some people concerned that taking it could result in dehydration. This could worsen dehydration due to the vomiting and diarrhea a person typically experiences during a stomach bug. Charcoal itself can also sometimes cause vomiting.

Again, there is a lack of research on this. However, as dehydration is already a risk of stomach bugs, people should not try activated charcoal without getting the approval of a doctor.

It is unclear what dosage of activated charcoal is safe. There are also no data on whether it is safe to use during a stomach bug or during pregnancy.

Stomach bugs usually resolve by themselves without treatment. A person does not need to take charcoal or any other supplement to make this happen.

However, if the symptoms are severe, do not go away on their own, or get worse, a person should contact a doctor as soon as possible.

If an adult or child is showing signs of significant dehydration or cannot keep fluids down, it is essential to dial 911 or the number of the nearest emergency department.

The signs of dehydration in adults include:

  • extreme thirst
  • dark yellow urine
  • passing little to no urine
  • dry mouth, lips, or eyes
  • dizziness
  • confusion
  • difficulty staying awake
  • unconsciousness

The signs in babies and young children include:

  • drowsiness
  • fast breathing
  • dry mouth
  • few or no tears when crying
  • dark yellow urine
  • cold hands and feet
  • a soft, sunken spot on the top of the head

Activated charcoal is not a proven treatment for stomach bugs. It also cannot prevent someone from getting a stomach bug. However, most stomach bugs will improve on their own without treatment.

It is advisable to speak with a doctor before trying activated charcoal for a stomach bug. This substance may help some people reduce or stop diarrhea, but it may not be suitable for everyone.