Which method of medication administration involves taking substances by mouth for gastrointestinal absorption?

The method of medication administration that involves taking substances by mouth for gastrointestinal absorption is the oral route. This route is the most common and typically considered convenient for patients. When medications are taken orally, they dissolve in the gastrointestinal tract and are absorbed into the bloodstream, allowing the active ingredients to exert their effects throughout the body.

Oral administration allows for a diverse range of formulations, including tablets, capsules, and liquids, making it suitable for various types of patients and conditions. It generally provides a more gradual onset of action compared to other methods, contributing to the stability of drug levels in the bloodstream.

Other routes of administration, such as the parenteral route (which includes injections), intravenous route (directly into the bloodstream), and topical route (applied to the skin or mucous membranes), do not involve gastrointestinal absorption, thus differentiating them from the oral route.