Activated Charcoal-A Monograph

Introduction

This blog started from a series of social media posts. One evening, I wanted to post about a subject I knew well but wouldn’t require much research. Ironically, I fell down the activated charcoal hole and spent 2 weeks studying activated charcoal (AC) and have written nearly 5000 words about it. And learned a thing or six. My interest in AC comes from my many years of using it at large, outdoor off-the-grid events. I mainly use it to treat staph infections and gastrointestinal infections. Both of these conditions were unfortunately common in some of the situations I worked in.

One tricky aspect of researching AC is that it is a polarizing subject. Many supporters of its use (often product sellers) espouse the myriad ways it can be beneficial, while the mainstream medical community tries to put the brakes on this over-the-top popularization. What makes it challenging is the lack of studies for many of its uses. Both sides make claims that are difficult to back up with scientific or clinical research. Much of the positive information is anecdotal and speculative. This does not make it inaccurate; it just means that AC’s benefits are unclear. Fortunately, it is considered reasonably safe (see safety), though safe and effective are two very different qualities.
The apprehension seems warranted as AC is regularly touted to have nearly miraculous properties.

There is always the concern that people taking in AC may not seek proper medical care (though this is a concern with all ‘non-medical’ treatments).  

Of course, there are many situations in which it is not possible to seek medical treatment, including a lack of access, expense, past difficulties in medical settings, and legal issues.

Full disclosure. I am a clinical herbalist and not a trained medical professional. I have spent a lot of time practicing first aid and health care under the guidance of experienced hands as well as self-study.

What is Activated Charcoal

Activated charcoal is a highly porous form of carbon prepared by burning organic matter at very high heat in the absence of oxygen and then activating it with either high-temperature steam or through chemical processing. The first part reduces the matter to mostly carbon, and the second further refines it and increases its porosity (the amount of pores it contains).

This process makes it different than biochar and the charcoal formed from burnt toast or wood.

Adsorbent versus Absorbent

AC is an adsorbent, which is the most important aspect in understanding its usage. There is a big difference between adsorption and absorption. Absorption is the assimilation of a material throughout a substance, such as a bandage absorbing blood, a sponge absorbing water, or the small intestines absorbing nutrients. Adsorption is a process in which a substance adheres to the surface of a material. This produces a much stronger molecular bond than absorption. In my mind, it looks similar to an object attached to a magnet (though the processes are entirely different).

Here is a thought experiment. If you had intestinal bacteria, such as E. coli, and swallowed a sponge, it would absorb some of the bacteria as it passed through your digestive system, but the bond is weak, and the bacteria would move out of the sponge during passage. Also, the sponge would have little selectivity about what it absorbs. With activated charcoal, the bond between the bacteria is much stronger. The bacteria will remain attached to the AC and will pass with the stool during a bowel movement (which will be black due to the AC).

The cause of this strong bonding is due to the activation process, which increases the porosity of each grain of charcoal. These pores greatly increase its surface area. The numbers are difficult to comprehend, but 1 ounce of AC has a surface area of approximately 200,000 square feet. This is 1000 times more than charcoal obtained from burnt organic material (which can still be helpful). This huge surface area can bind and hold a large quantity of material. AC tends to bond strongly to some substances and more weakly to others.

It binds to a number of toxins, such as chlorine and pesticides. It also bonds with several medications, including barbiturates and acetaminophen. This is why its primary medical use in hospitals is for drug overdoses. It needs to be given within an hour or two after ingestion. These are just a few of the many substances that bind with AC. 

AC only forms weak bonds with water. This increases its usefulness internally, as it releases its bond with water to bind with other substances.  

The main way I use activated charcoal is in treating bacterial gastrointestinal illnesses such as E. coli and Salmonella, as well as their endotoxins and exotoxins. It can also be used externally to help draw out bacteria in wound care.

AC only works when it comes into direct contact with substances. Hence, internally, it only works in the GI tract. And it is not helpful for viruses, as they are found within cells. This means it is not beneficial for stomach viruses such as norovirus.

All of the AC taken internally will be excreted. This means it will not be helpful for other organs, such as the urinary or respiratory tract.

Activated charcoal binds various substances and prevents their absorption. It does not kill organisms; it only traps them to be excreted later.  

Aside from medicine, AC is commonly used in many industrial processes for its filtration properties as well as in water filters.

Types of Activated Charcoal

I have traditionally used food-grade AC, which I have found beneficial. But in the future, I will be switching to AC prepared from coconut shells, as their pores are smaller and can more actively bind with small substances.

 The Take Away

Activated charcoal’s benefits are due to its adsorption properties. When considering using AC, your main question should be, ‘Is my goal trying to adsorb something?’ Activated charcoal can only bind substances with which it comes into direct contact, meaning the digestive tract and the skin.

Definitions

1. Cohesive bandage-a type of lightweight self-adherent bandage that does not stick to the skin. It is useful for holding dressings in place. Brand names include Vetrap and Coban.
2. Diverticulitis/Diverticula-Diverticulitis is an inflammation of the large intestine that creates pouches. The pouches are called diverticula.
3. Escherichia coli (E. coli)-a bacterium that is a normal part of the gut flora, but some strains can cause food poisoning, often through the fecal-oral route.
4. Endotoxin-toxic fragments of the outer wall of a dying or broken apart bacterium.
5. Exotoxin-toxins released by living bacteria that disrupt normal cell function to colonize the host.
6. Exudate: the fluid that leaks into wounds and contains cellular debris, dead white blood cells, and other constituents. Pus is a type of exudate.
7. Mycotoxin-a group of poisonous substances made by molds and fungi.
8. Salmonella-(named after Daniel Salmon) a genus of bacteria that commonly causes foodborne illness.
9. Staphylococcus aureus (staph) infection-a bacterium commonly found on the skin and other parts of the body, which can be innocuous or cause infections such as boils and cellulitis. It is the most common causative agent for skin infections.

Medicinal Properties

Activated charcoal has long been used for adsorbing ingested toxins and drug overdoses. I’ve had little experience with this use and will focus on the ways I have utilized AC. The few times I’ve been around non-narcotic overdoses, the person was brought to a hospital or clinic. And I always carry naloxone for narcotic overdoses.

There are two main ways I’ve used activated charcoal. They are for food and water poisoning and infectious wounds.

Food and Water Poisoning

These can be severe health situations that require medical attention. This is especially true for people with a more fragile constitution, immune disorders, or other health conditions, as well as young children. Some of the primary causes of foodborne illness are bacteria such as E. coli and Salmonella, as well as viruses (i.e., norovirus) and protozoa (ex. Giardia).

I have worked with foodborne illnesses quite a few times. This has been a result of working at large off-the-grid events, with people cooking in rudimentary kitchens, feeding many people, as well as people eating rancid foodstuffs. Many of these kitchens are kept as sanitary as possible considering their environment, but bacteria, viruses, and other pathogens can still slip into food and water sources. The most common symptoms include diarrhea, vomiting, nausea, and stomach cramps. The sequelae often include fatigue, a lack of appetite, and ongoing nausea. A fever indicates a more serious case. The AC is only helpful for adsorbing bacteria and protozoa, not viruses. Other herbal preparations and medicines are required to kill the infectious organisms and reduce the symptoms.

 

The reality is that we often do not know what is causing people’s gastrointestinal distress at these events, as we do not have access to labs. But when we see groups of people with similar symptoms, it is assumed to be due to something in the food or water. But the causative pathogen is not obvious, whether it is bacterial, viral, or other. Viruses are more likely to cause a fever, though this is not always the case. The symptoms of Giardia are more obvious and usually take a few days to develop.

In general, if we are unsure, we will administer activated charcoal, as it may help with bacterial infections, but not worsen viral infections, and it is well-tolerated.

AC Preparations and Treatment

The primary forms used are powder and capsules. Depending on how often you use it, I suggest purchasing it in bulk, as it is much less expensive. For an adult, the initial dosage is about 1 teaspoon stirred into a half cup of water. Fortunately, water forms a weak bond with AC. This allows it to potentially adsorb more bacteria and toxins after being ingested. You can also use 4/00 capsules.

I suggest doing this regimen at least 2-4 times over the course of two to three days with either preparation.

It should be done at the very first sign of GI illness. AC cannot be used when there is vomiting or severe nausea, as its coarse texture can irritate the stomach and induce vomiting. Vomiting will also negate any beneficial AC effects.

Do not take medicines at the same time as AC, as they will be adsorbed, decreasing the utility of both the medicine and the AC. For instance, do not add AC to a tincture mix that you will be giving someone.

Activated Charcoal for External Infections

As with other aspects of using activated charcoal, there is some debate in the medical community about its usefulness for external infections. It is not always my first choice, as it is messy to work with, but I have found it helpful for more stubborn infections.

At some of the first-aid stations I’ve worked at, we regularly see people with Staphylococcus aureus (staph) infections, mainly on the feet and lower legs.

Externally, I usually start with an antibacterial, disinfecting tincture or liniment. (Note: I’ve written about treating staph infections elsewhere; the focus here is on the use of AC.) If that seems ineffective, I usually alternate it with AC.

The reason for using AC in wound care is its adsorbent property. It is not clear whether it directly interacts with the harmful bacteria (usually staph), but it may adsorb exotoxins, as well as remove excess exudate that impedes the healing process. AC also reduces wound odor, but this is usually associated with more serious infections that should be treated in a medical setting.

I usually avoid applying AC directly into a wound. This would allow it to come into direct contact with the infectious agent, but it also impedes the wound’s ability to heal. The body needs to remove any extraneous material before the tissue can regenerate. Its black coloration also makes it difficult to assess the condition of the wound. This means the AC must be removed between assessments and before redressing. Removing the AC can be a painful experience, so I only use this method when there is a lack of supplies, such as while camping or traveling.

The indirect method involves layering the AC on wound-dressing material, such as gauze, to form an ‘AC sandwich.’ There are also commercial wound dressings that contain AC (often containing silver). For these uses, the AC is slightly moistened and spread on a gauze pad with another gauze pad placed over it. The moistened pad is placed against the infected wound and held in place with a cohesive bandage. This is preferable to using tape, as tape can pull out hairs when changing the dressing, which creates more opportunities for bacteria to infiltrate beneath the skin.

This dressing may cause some AC staining of the skin, but the particles will not be in the open wound, making it easier to clean up.

Change the dressing about once a day, at least initially, to check on the wound’s progress. Also, to make sure no other open wounds are occurring nearby.

Important: If the infection appears serious, is quickly spreading, or is in a location that might lead to problematic scarring (such as the face), seek medical help.

How to prepare an AC wound dressing

Materials needed

• Activated charcoal powder
• Small mixing bowl
• Spoon for mixing and spreading
• Water
• Gauze pads, 2
• Cohesive bandage
• Surgical tape

Directions for a 4×4 dressing

1. Put approx. 3 teaspoons of AC in a small bowl
2. Add approx. 15 ml of water and stir until thoroughly mixed

*Note: This should give the consistency of thin mud. If more water needs to be added for the right consistency, add small amounts at a time. It is very easy to oversaturate the AC.

3. Spread the mix onto the gauze. There should be enough on the gauze pad to cover and slightly overlap the infected area.
4. Put the second gauze pad on top of the first.
5. Place it over the wound, AC side down, and hold in place with a cohesive bandage.

*Note: if the bandage will not stay in place, put the surgical tape on top of the bandage, not on the skin.

6. Remove and inspect the wound within a day. Check to see if any other infections are appearing nearby.
7. Make a new AC dressing and apply
8. Continue checking and applying new dressings as needed

* Note: if there is a lot of exudate, it will need to be changed more often.

Activated Charcoal Safety

While AC’s adsorptive qualities have medicinal benefits, it may also have some potentially adverse effects.

In the whole, activated charcoal is very safe, both internally and externally, but there are situations where it should be used cautiously or avoided.

Digestive Considerations

Avoid taking AC with diverticulitis, as the granules can get caught in the diverticula and potentially worsen irritation and inflammation, though this is uncommon.

AC can cause bowel obstructions. This is rare and occurs with large multi-doses given for overdoses in a clinical setting.

Since AC is an adsorbent, it can cause constipation by adsorbing fluids in the digestive tract, thereby bulking up and drying feces. This can also slow down peristalsis, leading to difficult bowel movements. Anyone taking AC internally should stay sufficiently hydrated to avoid this problem.

Nutrient malabsorption: It makes sense not to ingest AC while eating. The goal of AC is adsorption, while the goal of eating is to absorb nutrients. There is not a lot of evidence on how much AC will decrease nutrient absorption, but it may be a good idea to wait a while between eating and taking AC.

Gut biome: there is a concern that AC will disrupt normal gut flora, as it is not picky about what it adsorbs. But there is little evidence supporting this. And if you are taking AC for a GI bacterial infection, there is likely already a disruption of normal gut flora.

Adsorbing Medications

This is the most critical safety consideration when taking activated charcoal. AC may adsorb medications, thus reducing their efficiency. This includes birth control pills (BCPs), heart medicines, and antidepressants. The science is unclear on exactly how much AC is needed to adsorb drugs, and also how long to wait before or after taking AC. For BCPs, one study showed no change in their efficacy when the AC was taken 3 hours after the BCPs were taken. There were also no changes when the BCPs were taken 12 hours after AC ingestion.

A simple guideline is not take medications and AC at the same time. The general rule is to wait at least 2 hours after taking medicines before ingesting AC. And to wait at least 2-4 hours after taking AC before ingesting any medications. This does not apply to medications not taken orally, such as those administered by injection or skin patches.

With herbal medicine, it depends on which preparations are taken. Since tinctures are alcohol-based, they are absorbed quickly, and AC can likely be taken about 30 minutes after ingestion. With capsules, wait at least 2 hours before taking AC as they are absorbed more slowly. And again, wait at least 2 hours after ingesting AC.

Respiratory Aspiration

Aspiration is the inhalation of foreign material into the lungs. With AC, it is an uncommon but dangerous situation that can occur while treating overdoses in medical settings. It is unlikely to happen outside of these events. Still, AC is a very light substance and easily inhaled. I have not found any studies on this type of AC exposure, but it is best not to inhale any foreign particles. I suggest wearing a face mask if exposed to AC powder.

Allergies

For people allergic to coconut shells, it is generally safe to take AC made from them, as the heating and activation processes remove the allergenic constituents. Though there have been rare cases of people reacting. If someone has anaphylactic reactions to coconut, it would be prudent to use another form, such as AC made from hardwood.

What I Learned

It is clear that the world of mainstream medicine is worried about the popularization of AC. And I agree we should be careful, but there seems to be is a lot of extrapolation from little data. For instance, there appear to be few research studies showing that AC decreases nutrient absorption while eating. With many of the warnings, there are very few specifics, for instance, on how much AC is needed to cause a particular adverse reaction. And as far as nutrient absorption and gut bacteria, while it makes sense to not eat at the same time as taking AC, there are few studies corroborating this effect. Likewise, while it might theoretically decrease beneficial gut flora, there is little evidence that this occurs at the levels generally consumed by the public.

And while it makes sense not to take AC with medications, unfortunately, there is not much data indicating how much AC is needed to bind the medication. There are warnings about AC possibly causing or worsening bowel obstruction, though this is due to hospital use for treating overdoses. The same applies to respiratory aspiration.

There are also multitudes of inaccurate medicinal claims about AC on social media. Many of these statements come from folks selling products, which should always get a closer look before believing the hype. Many of the suggested benefits are outside the range of where AC can work, for instance, affecting the kidneys. I don’t think all of these folks are being purposefully misleading, but their claims are often unsubstantiated.  

Safety Tips and Guidelines

1. In general, AC is considered safe both externally and internally with proper dosing.
2. Remember that AC is an adsorbing agent. It can only work on substances with which it comes into direct contact. Its main uses are on the skin and along the digestive tract. It does not get into the bloodstream and cannot directly affect the kidneys or other organs.
3. Don’t use it if you don’t need it. It is not a ‘superfood’, it is a substance with specific uses.
4. Avoid taking AC while eating, unless it is for a specific purpose. The goal of eating is to absorb nutrients; the goal of AC is to adsorb (bind) substances.
5. Don’t take it at the same time as medicines. Even if it binds only a small amount, it may reduce their therapeutic effects.
6. When making capsules or when working with the powder, avoid inhaling it. Consider wearing a face mask.
7. This may seem obvious, but AC is not the same as charcoal briquettes.
8. If someone has overdosed or ingested toxins and is conscious, you may consider giving them AC and bringing them to a medical facility for observation and possible treatment.
9. While AC is generally safe as a toothpaste, its granular structure may be abrasive, wearing away enamel over time.
10. A significant concern is not taking a medical issue seriously enough when an individual might need medical care. While there are serious flaws in our medical system, sometimes rapid medical assessment and treatment are necessary.
11. Larger quantities of AC may be helpful for gut bacterial infections; it should be reduced and stopped when the infection has passed.
12. AC will color the stools black, which may frighten people, as it may appear to be congealed blood. There is no harm in this coloration.
13. Do not take AC if you have bowel obstructions.
14. It is helpful to always have AC in the home or while traveling. When it is needed, it might be needed right away.
15. Consider researching the benefits and safety of activated charcoal before using it for any specific condition.

Activated Charcoal Preparations

Once AC is added to another substance, such as a tincture, the AC will begin to adsorb some of its constituents, making it less effective at binding to other substances and reducing the tincture’s medicinal benefits.

AC Preparations

The below products are commonly sold. There is little research verifying the benefits of these combinations. Most of the claims are proposed by people and companies that sell these products. I am not saying they are not effective; it is just challenging to evaluate their efficacy. Since they pose little risk, there is no reason not to try them or stop using them if they feel beneficial for you.

Honey with AC

This is generally applied in skin care for honey’s emollient properties and AC’s adsorptive properties. The fact that it is often left on the skin for a while gives the AC a chance to adsorb oils. The question is: will it preferentially adsorb skin oils, or will the honey base reduce its binding capacity?  

Salves with AC

These are generally sold as drawing salves, but it is unclear how effective AC is in an oil and beeswax base. The reason is that AC actively adsorbs oil, which may make it less effective at drawing out substances from the body. But this is just speculative, as there is not much evidence either way.

Toothpaste with AC

The abrasive nature of AC may help remove external stains from teeth, but this same property can wear down enamel over time and potentially irritate the gums. The general rule is to use AC toothpaste only a few times a week and not scrub too hard. If you are making your own, use AC powder and not granules. See halitosis below.Soap with AC

The abrasive quality of AC can help exfoliate skin, though it is less clear whether it can adsorb bacteria or other particles on the skin, as it is generally washed off soon after application.

Clay versus Activated Charcoal

There are many types of clay depending on the minerals that make up its composition. Bentonite clay is often considered one of the most medicinal clays due to its adsorbent and absorbent properties. AC is preferred for medical applications due to its much larger surface area. It is also much lighter, making it easier to ingest. For wound care, AC is preferred for its stronger adsorptive properties. Clay is generally preferable in body care as it can adsorb and absorb oils and other materials from the skin. It also applies and washes off more easily than AC, with no skin-staining properties.

Health Conditions

Detox

This is a tricky and contentious issue. The main detoxifying organs in the body are the kidneys and liver. They modify substances in the bloodstream, keeping what’s needed and excreting the waste. Outside of that physiology, the term detox can mean almost anything. I am concerned that ‘detoxing’ can often be non-productive and even harmful. When using AC to detoxify, one question is: What is the overall goal? As mentioned previously, AC can potentially remove bacteria and exotoxins from the GI tract, but it cannot enter the bloodstream. For this reason, AC is not a good general detoxifying agent, unless used for specific conditions on the skin or in the gut.

Halitosis (bad breath)

AC can reduce some forms of halitosis, especially when the condition originates in the oral cavity, by adsorbing gases and bacteria in the mouth. If chronic, it may be due to an underlying infection. AC containing toothpaste is the most common way to use it for this condition. AC is abrasive, and excessive scrubbing may damage tooth enamel.

Poison ivy dermatitis

AC will not help a poison ivy rash once it is established. It may be helpful to apply it as a paste immediately after contact with the plant, by adsorbing the allergenic plant oil (urushiol). Washing thoroughly with a strong soap is likely more helpful and is easier to apply and remove.

Gas and bloating

AC may be helpful for some folks with gas (and thus, bloating), though there is little research or clinical studies showing improvement. Avoid taking too much, as it can be drying and cause constipation (see safety).

Mold

Much of mold’s toxicity comes from inhaling its spores and volatile organic compounds (VOCs). These pass into the lungs, where they can cause mold-related illnesses or allergies. This part of mold toxicity cannot be treated with AC because of its location in the body. But some of the mycotoxins may be in the GI tract. This can happen when mucus from the respiratory tract is swallowed, or when dust or other mold-laden particles are ingested. While there is little evidence of this helping, it seems theoretically plausible.

Spider bites

The vast majority of what people think are spider bites are usually staph infections. It is unclear whether AC will adsorb the venom from a poisonous spider, but it seems reasonable to try, especially if used soon after being bitten. Medical assistance may also be required.

AC Costs

It is much less expensive to purchase bulk powder rather than pre-made capsules. Currently (2026), 100 capsules cost about $12.50. This comes down to $12.50 for 1 oz of AC (each capsule is 280 mg). Bulk AC costs approximately $22/lb, which equals $1.40¢/oz. The powder can be used without putting it in capsules. But filling AC capsules is not only tedious, but also messy. It is very lightweight, and the powder will float around, getting into clothing and skin. Be careful not to inhale it. Due to the challenge in preparing the capsules and depending on how often the AC is used, the price difference may be worth it.

A Parting Note

There are many aspects I haven’t covered about activated charcoal, but hopefully this is a good start. If you’ve made it this far, congratulations. The next time you are at a social event and the conversation turns awkward, you can bring up all the virtues and fallacies of activated charcoal and become the life of the party.

A little more seriously, I hope this information will be helpful to you and those around you. I have found AC beneficial, particularly while practicing first aid. Thank you for caring for yourself and those around you.