Charcoal in Medicine- Carbon obtained It is also used to absorb odors and toxins in gases, such as air. Charcoal filters are also used in some types of gas masks. Activated charcoal. The medical use of activated charcoal is mainly the absorption of poisons. Activated charcoal is available without a prescription, so it is used for a variety of health-related applications. Skin and Body Health: Activated charcoal uses extend beyond internal applications. For external treatments, its effective at treating body odor and acne and relieving discomfort from insect bites, rashes from poison ivy or poison oak, and snake bites.