Charcoal tablets or capsules are made from activated carbon and intended to treat food or mercury poisoning, and drug overdoses.
Activation is by heat or other treatment that increases absorptive capabilities. The charcoal binds to chemicals in the gut and helps them pass harmlessly out of the body. As detoxifiers, charcoal may put extra pressure on your kidneys and liver.
It is considered to be an Essential Medicine by WHO, but it will not affect some poisons: ethanol, arsenic, iron, lithium, lye, petroleum products, and strong acids.
Charcoal may bind to prescription drugs and supplements, and even vitamins and minerals from food, reducing effectiveness, so take internally two hours before medications or meals, or one hour after to avoid interaction.
Inhaling charcoal dust is extremely dangerous and can result in death. Avoid using activated charcoal with sorbitol, which can cause severe diarrhea and vomiting.
Ingesting charcoal can lead to side effects like nausea, vomiting, constipation and bowel obstruction. These usually occur with high doses, but proceed with caution. People suffering from constipation, diverticulitis, colitis or bowel obstruction should certainly consult their physician or a poison control center before treating themselves with charcoal.
Do not take charcoal on a long-term basis as it can lead to nutritional deficiencies. Do not give charcoal to children and, while there is no evidence of harm, it might be a good idea not to take charcoal freely if you are pregnant or nursing. Do not use activated charcoal if you have bowel obstruction or constipation.
After taking charcoal, drink plenty of fluids to help you avoid constipation.
Call your doctor if you have an allergic reaction, like itching, hives, swelling breathing difficulties, chest tightness, severe diarrhea or constipation.