How long does it take for oral medication to be absorbed by the stomach?

The absorption time of oral medications in the stomach varies greatly, generally ranging from 15 minutes to 2 hours, primarily depending on the drug formulation and properties.

Solid dosage forms such as conventional tablets and capsules usually require 15 minutes to 2 hours to disintegrate into particles or powder in the stomach before they begin to be gradually absorbed by the gastric mucosa or enter the small intestine via gastric emptying. For example, common cold medications such as acetaminophen tablets generally begin to disintegrate and be absorbed in the stomach within about 30 minutes, reaching peak blood concentration approximately 1 hour later. In contrast, some poorly soluble drug capsules may require 1.5 to 2 hours before significant absorption occurs.

Liquid formulations such as oral solutions and suspensions do not require a disintegration process and can come into direct contact with the gastric mucosa, resulting in faster onset of absorption, usually within 10-30 minutes. For example, ibuprofen suspension can exert antipyretic effects approximately 30 minutes after administration in children. The actual absorption rate of a drug in the stomach is also influenced by gastric emptying speed and other factors such as food intake.

Under fasting conditions, the stomach empties more quickly, allowing the drug to rapidly enter the small intestine, potentially advancing absorption by 30 minutes to 1 hour. However, taking medication after a meal may delay gastric emptying due to the presence of food, potentially postponing the onset of absorption for solid dosage forms by 1-2 hours. To ensure optimal therapeutic effects, patients should follow medical instructions and choose appropriate medication times under the guidance of physicians or pharmacists, while also paying attention to dietary habits to promote drug absorption.