Question: 161. Why can’t insulin be given orally to diabetic patients?
(1) Human body will elicit strong immune response
(2) It will be digested in Gastro-Intestinal (GI) tract
(3) Because of structural variation
(4) Its bioavailability will be increased
Answer: Option (2)
Explanation:
Insulin is a protein hormone. If it is taken orally, the enzymes of the Gastro-Intestinal (GI) tract break it down into amino acids, just like any other dietary protein.
Because of this digestion, insulin cannot reach the bloodstream in its active form.
Therefore, orally administered insulin becomes inactive before absorption, making oral intake ineffective.
For this reason, insulin is administered through injection so it directly enters the bloodstream.