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Why is activated charcoal bad for you?

Activated charcoal has become a popular health and wellness trend in recent years. Proponents claim that it can whiten teeth, reduce gas and bloating, lower cholesterol, treat poisonings, and improve skin health. However, there are also potential downsides to ingesting activated charcoal that need to be considered.

What is Activated Charcoal?

Activated charcoal is a fine, black powder made from materials like coconut shells, coal, wood, or petroleum. The charcoal is “activated” by processing it at very high temperatures. This opens up millions of tiny pores between the carbon atoms. As a result, just one gram of activated charcoal has a surface area of 500-2,000 square meters.

This huge surface area gives activated charcoal its ability to adsorb – attract and bind to – substances. In emergency rooms, activated charcoal is sometimes used to treat poisonings and overdoses. It prevents toxins from being absorbed from the digestive tract into the bloodstream. However, it also adsorbs important nutrients, minerals, and medications as well.

Uses of Activated Charcoal

In addition to emergency medical treatment, activated charcoal has become popular for other uses:

  • Teeth whitening – Charcoal can absorb stains and discoloration.
  • Skin care – Charcoal masks and soaps claim to remove oil, dirt, and toxins from skin.
  • Flatulence – Charcoal capsules may help reduce gas and bloating.
  • Hangover remedy – Charcoal may help absorb alcohol and toxins, reducing the effects of hangovers.
  • Water filtration – Charcoal filters can remove some contaminants from water.

Is Activated Charcoal Safe to Take?

While activated charcoal has some legitimate medical uses, taking it routinely or long-term may cause problems. Here are some potential downsides of using activated charcoal supplements:

Reduces absorption of nutrients

One problem with activated charcoal is that it doesn’t just absorb toxins or excess gas. It also adsorbs important nutrients from foods, including:

Nutrient Amount Reduced
Vitamin C Up to 50%
Calcium Up to 41%
Iron Up to 57%

Regular use of activated charcoal could lead to nutritional deficiencies in essential vitamins, minerals, amino acids, and other nutrients. This is especially concerning with long-term use.

Interferes with medications

Just as it does with nutrients, activated charcoal can prevent medications from being properly absorbed. This includes prescription drugs as well as over-the-counter medications like aspirin, antacids, and thyroid medications.

Taking charcoal along with regular medications essentially makes many of them less effective. It is essential to take activated charcoal separately from other supplements or medications by at least 2 hours.

Impact on gut bacteria

The microorganisms that live in the digestive tract are essential for health. They help digest food, regulate the immune system, produce important vitamins, and protect against harmful bacteria.

Studies show that activated charcoal drastically reduces populations of these essential gut bacteria after only a few days of use. More research is needed, but charcoal could potentially disrupt the balance of bacteria in the gut microbiome.

Contains filler ingredients

Activated charcoal supplements are not pure charcoal. They typically contain fillers like soy protein, carrageenan, citric acid, and other stabilizers. The long-term safety of these added ingredients is not known.

Causes constipation

A common side effect of activated charcoal is constipation. Charcoal can absorb water in the digestive tract and slow the passage of stool. A doctor should be consulted if severe constipation occurs.

In addition, charcoal in the intestines can blacken the stool. This is harmless, but can be alarming if you are not expecting it.

Should You Take Activated Charcoal Supplements?

Here are some guidelines on when activated charcoal may or may not be appropriate to take:

May be effective for

  • Accidental food poisoning
  • Traveler’s diarrhea
  • Gas and bloating
  • Skin health

Likely ineffective or harmful for

  • Colon cleansing
  • Hangovers
  • Lowering cholesterol
  • Daily detox and wellness
  • Teeth whitening

It is best to consult a doctor before using activated charcoal if you take any medications or have any chronic health conditions. Never take it routinely or long-term without medical supervision.

Safe Ways to Take Activated Charcoal

When used occasionally, activated charcoal is likely safe for most healthy adults. However, it should be taken cautiously and correctly:

  • Take at least 2 hours before or after medications or supplements.
  • Start with low doses like 500 mg capsules.
  • Drink plenty of water and rehydrate after taking it.
  • Take for short periods only, less than 3 weeks.
  • Consult a doctor before using if pregnant, breastfeeding, or giving to children.

Activated charcoal should never be taken with prescription medications without a doctor’s approval. It also may not be ideal for certain groups like pregnant women, older adults, or people with intestinal issues.


Activated charcoal does have some legitimate medical uses. However, using activated charcoal supplements routinely or long-term can interfere with nutrient and medication absorption. It may also disrupt gut bacteria populations. In general, activated charcoal is likely safe only if used occasionally and correctly under medical supervision.