Why can't insulin be given orally to diabetic patients?

Question

Why can't insulin be given orally to diabetic patients?

1. A. Human body will elicit strong immune response
2. B. It will be digested in Gastro-Intestinal (GI) tract (Correct answer)
3. C. Because of structural variation
4. D. Its bioavailability will be increased

Correct Answer

Option B — It will be digested in Gastro-Intestinal (GI) tract

Detailed Solution & Explanation

The correct answer is It will be digested in Gastro-Intestinal (GI) tract.

Key Points

• Insulin is a protein (polypeptide) hormone. If taken orally it would be broken down by the proteolytic enzymes in the gastro-intestinal tract before it could act.
• Hence insulin is administered by injection, not orally.