Activated charcoal is a black, odorless, flavorless powder that has been used since ancient times to treat various ailments.

Nowadays, it’s most commonly utilized in medical settings to treat drug overdoses or as an emergency anti-poison remedy.

Activated charcoal is thought to offer several other benefits, including less gas and flatulence, lower cholesterol levels, and improved kidney function. Some people claim that it helps whiten your teeth, filters water, and even cures hangovers.

Still, you may wonder how many of these claims are backed by science.

This article reviews what activated charcoal is, as well as its evidence-based benefits, side effects, and dosage.

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Activated charcoal is charcoal that has been treated with oxygen at very high temperatures to make it more porous. This treatment changes its internal structure, reducing the size of its pores and increasing its surface area (1, 2).

The resulting fine black powder is either sold as is or encapsulated as supplements. Activated charcoal is also added to various food and nonfood products, from ice cream to toothpaste.

Interested in activated charcoal products?

Take a look at our list of the best activated charcoal toothpastes.

It shouldn’t be confused with the charcoal briquettes in your grill or barbecue.

While both may be made from the same base materials, charcoal briquettes haven’t been activated at high temperatures. Moreover, they contain additional substances that are toxic to humans.

Summary

Activated charcoal is a type of charcoal that’s processed to make it more porous. It’s sold in both supplement and powder form, as well as added to various food and household products.

Activating charcoal with gas at high temperatures causes it to develop microscopic holes, which increase its surface area.

Activated charcoal doesn’t get absorbed by your gut. Thus, after you swallow it, it reaches your gut in its unchanged form (3).

The charcoal’s porous texture has a negative electrical charge, which causes it to attract positively charged molecules, such as toxins and gases. When liquids or gases pass through this activated charcoal, they bind to it through a process known as adsorption (4).

These toxins and chemicals get trapped in your gut and eliminated through stool instead of being absorbed into your body (4).

Activated charcoal is also very effective at adsorbing gases, which can help reduce flatulence (1).

Summary

Activated charcoal’s negatively charged, porous texture helps trap toxins, preventing your body from absorbing them. It is also effective at trapping gases to alleviate flatulence.

Activated charcoal has several potential health benefits.

However, some of these benefits rely on research that is decades old, so their validity should be taken with a grain of salt.

Furthermore, you should not self-administer activated charcoal as a poison or overdose treatment. If you suspect poisoning or overdose, it’s best to seek emergency medical assistance immediately.

Emergency poison treatment

Activated charcoal has been used as an emergency anti-poison treatment since the early 1800s. That’s because it can bind to a wide variety of drugs, reducing their effects (2, 5).

This substance may be used to treat overdoses from both prescription drugs and over-the-counter medications like aspirin, acetaminophen, and sedatives (3).

Studies show that ingesting 50–100 grams of activated charcoal within 5 minutes of taking a drug may reduce an adult’s ability to absorb that drug by up to 74% (2, 3).

Activated charcoal is said to be most beneficial when taken within the first hour after an overdose or poisoning. Older studies suggest that taking it after this initial hour is unlikely to help (3).

However, newer research reports several cases in which it was effective even when taken past this first hour. This may be because activated charcoal not only stops a drug from being absorbed but also helps your body eliminate already absorbed drugs more quickly (6, 7).

Moreover, research suggests that activated charcoal may be beneficial if taken up to 4 hours after ingestion of delayed-release drugs, those which slow digestion, and large drug doses (3).

In medical settings, the initial dose of 50–100 grams is sometimes followed by several smaller doses of 10–25 grams, taken every 2–4 hours for up to 6 hours (3).

This multiple-dose activated charcoal (MDAC) protocol may aid intoxications from slowly absorbed drugs (3, 8).

Although more research is needed, MDAC may be especially beneficial in cases of life threatening ingestion of dapsone, phenobarbital, quinine, carbamazepine, and theophylline (3, 8).

It’s important to note that activated charcoal is not effective in all cases of poisoning. For instance, it appears to have little effect on alcohol, heavy metal, iron, lithium, potassium, acid, or alkali poisonings (2, 4, 8).

Both old and new studies warn that activated charcoal shouldn’t be routinely administered in all cases of poisoning. Rather, its use should be considered on a case-by-case basis by qualified healthcare professionals (1, 3, 9).

May promote kidney function

Activated charcoal may promote kidney function by reducing the number of waste products that your kidneys have to filter (10).

This may be particularly beneficial for people with chronic kidney disease. Healthy kidneys are normally very well equipped to filter your blood, but this condition inhibits your kidneys’ ability to remove urea and other toxins.

Activated charcoal may bind to urea and other toxins, helping your body eliminate them (10).

Urea and other waste products can pass from the bloodstream into your gut through a process known as diffusion. In your gut, they bind to activated charcoal and get excreted in stool (7).

Older human studies suggest that activated charcoal may help lower blood levels of urea and other waste products, as well as improve kidney function in people with chronic kidney disease (5, 11, 12).

One small study found similar results, but more research is needed (13).

May reduce symptoms of fish odor syndrome

Activated charcoal may help reduce unpleasant odors in individuals suffering from trimethylaminuria (TMAU), also known as fish odor syndrome.

TMAU is a genetic condition in which trimethylamine (TMA), a compound that smells like rotting fish, accumulates in your body.

Your body usually converts TMA into an odorless compound before excreting it through urine, but people with TMAU lack the enzyme needed to perform this conversion. This causes TMA to accumulate and enter urine, sweat, and breath, causing a foul, fishy odor (14).

Studies show that activated charcoal’s porous surface may bind to small, odorous compounds like TMA, increasing their excretion.

One small, older study gave people with TMAU 1.5 grams of charcoal for 10 days. This dosage reduced TMA concentrations in their urine to normal levels (15).

A more recent case study suggests that combining activated charcoal with medications and dietary changes may help reduce fishy odor in people with TMAU (16).

Larger, newer studies are needed to confirm these effects.

May reduce cholesterol levels

Activated charcoal may help reduce cholesterol levels.

Older research suggests that activated charcoal may bind to cholesterol and cholesterol-containing bile acids in your gut, preventing them from being absorbed (17, 18).

In one older study, taking 24 grams of activated charcoal per day for 4 weeks lowered total and LDL (bad) cholesterol by 25% each while raising HDL (good) cholesterol by 8% (19).

In another, taking 4–32 grams of activated charcoal daily helped reduce total and LDL (bad) cholesterol by 29–41% in those with high cholesterol levels. Larger doses were most effective (20).

Other studies have observed similar conclusions, though the results are mixed. Plus, all relevant research was conducted in the 1980s, so newer findings are needed (21, 22, 23).

Summary

Activated charcoal may treat poisoning, drug overdoses, and a condition called TMAU. It may also help lower cholesterol levels, though more research is necessary.

Activated charcoal is a popular home remedy for several other ailments — and it’s sometimes used for other household and cosmetic purposes. However, most of these purported benefits aren’t backed by science.

  • Gas reduction. One recent study reports that taking activated charcoal 8 hours before an abdominal ultrasound significantly reduces the amount of gas in your gut, making it easier to get a clear ultrasound image. Still, more research is needed (24).
  • Diarrhea aid. One case study indicates that activated charcoal may help treat diarrhea, but higher quality studies are necessary (25).
  • Water filtration. Activated charcoal may help filter water by removing contaminants, suspended solids, and microorganisms like bacteria — all without affecting the water’s pH or taste (26).
  • Tooth whitening. This substance is anecdotally said to whiten teeth when used as a mouth rinse or in toothpaste. It’s said to do so by absorbing plaque and other teeth-staining compounds. However, no studies support this claim (27).
  • Hangover prevention. Activated charcoal is sometimes touted as a hangover cure. However, this substance doesn’t effectively absorb alcohol, so this benefit is very unlikely (3).
  • Skin treatment. Applying this substance to your skin is said to treat acne, dandruff, and insect or snake bites. Yet, almost no evidence supports these claims (28).
Summary

Activated charcoal has various popular home uses. However, only gas reduction, diarrhea reduction, and water filtration are supported by science. More research is needed for almost all applications.

Activated charcoal is considered safe in most cases, and adverse reactions are infrequent.

That said, it may cause some unpleasant side effects, the most common of which are vomiting, especially if sorbitol is also used as an ingredient (3).

In very rare cases, activated charcoal has been linked to bowel blockages. You might be at a greater risk if you have gut motility disorders, take opioid or antimuscarinic medications, or are taking MDAC (3).

The American Academy of Clinical Toxicology (AACT) further warns against activated charcoal in cases of bleeding, blockage, or holes in your gut (3).

Moreover, when activated charcoal is used as an emergency poison antidote, there’s a risk that it can enter your lungs rather than your stomach. This is especially true if you vomit or are drowsy or semiconscious (2, 3, 8).

As such, this substance should only be given to those who are fully conscious (2, 3, 8).

Keep in mind that activated charcoal may also reduce the absorption of certain medications. If you’re currently taking other medications, it’s best to consult your doctor before taking this substance (2).

Summary

Activated charcoal is generally considered safe but may cause unpleasant side effects like vomiting. It may also interfere with some medications.

If you’re interested in trying activated charcoal for cosmetic or household purposes, it’s widely available online and in supplement stores. You can buy supplements in pill or powder form. If you opt for a powder supplement, mix it with water or juice to make it easier to swallow.

Make sure to follow the dosage instructions on the label, or use those in the studies mentioned above.

In the case of drug poisoning, seek medical help immediately. A medical professional may administer a dose of 50–100 grams of activated charcoal as soon as possible. Children are normally given a lower dose of 10–50 grams, depending on their age (3).

Note that dosages for other conditions are derived from older studies. Currently, these range from 1.5 grams to treat fishy odor disease to 4–32 grams per day to lower cholesterol and promote kidney function in those with end stage kidney disease (11, 12, 19, 20).

These recommendations should be updated as newer studies emerge.

Summary

Activated charcoal is available as a powder and pill. Be sure to follow the dosage instructions on the label.

Activated charcoal is a natural remedy with various uses.

It’s most commonly used as an emergency overdose or anti-poison treatment. Significant amounts of research back this application.

It may also help lower cholesterol levels, fight symptoms of fishy odor syndrome, improve kidney function, and reduce gas and diarrhea. Still, studies supporting these benefits tend to be older or limited in scope.

Activated charcoal can interact with other medications, so check with your doctor before trying it if you’re currently taking medications. You may also want to start with the lower end of the recommended dose to see how you react to it before increasing the amount.

Just one thing

Try this today: I found activated charcoal quite useful at reducing my symptoms of traveler’s diarrhea while visiting Southeast Asia a few years back. I’d recommend adding it to your list of over-the-counter remedies to bring on your next trip.