What is the typical onset delay for an orally ingested drug?

• A. 5-10 min
• B. 1-2 hours
• C. 2-3 hours
• D. 15-30 min

Answer: (D)

The time to first feel the effects of an orally ingested drug depends on how quickly the drug dissolves in the stomach and small intestine, is absorbed into the bloodstream, and reaches its site of action. For common oral formulations, this process typically begins within about 15 to 30 minutes after ingestion, which is why the onset window around 15–30 minutes is considered the best general estimate. Of course, peak effects may take longer and can vary with factors like the drug’s formulation, presence of food, gastric emptying, and individual differences. Shorter times (5–10 minutes) would usually involve routes that bypass the GI tract (like inhalation or injection), while longer times (1–2 hours or more) can occur with slower absorption or extended-release products.