EP 071:40

Why most peptide drugs are shots

Name: Why most peptide drugs are shots
Uploaded: 2026-09-28
Duration: 1 min 40 s
Description: A swallowed peptide is digested like food, so most peptide drugs are injected. The few pills work through clever chemistry, or by not being peptides at all.

A swallowed peptide is digested like food, so most peptide drugs are injected. The few pills work through clever chemistry, or by not being peptides at all.

Transcript and sources

Almost every peptide drug is an injection. So why can't you just swallow the pill?
Because your gut treats a swallowed peptide like food. Enzymes in the stomach and small intestine cut it into amino acids and tiny fragments, so usually less than one percent reaches the blood.
Size matters too. Aspirin weighs about one hundred eighty daltons. Semaglutide, about four thousand one hundred. Insulin, about five thousand eight hundred. An antibody, about a hundred and forty-eight thousand.
So drugmakers inject. Under the skin, about eighty-nine percent of semaglutide reaches the blood, and it lasts about a week.
In two thousand nineteen, Rybelsus became the first GLP-1 medicine you could swallow. Its trick is a helper called SNAC, which briefly buffers the acid around the tablet and shields the drug from digestive enzymes.
Even so, only about one percent gets in. That's why the label says: empty stomach, a small sip of water, then wait thirty minutes before eating.
In April two thousand twenty-six, the FDA approved orforglipron, sold as Foundayo: a GLP-1 pill that isn't a peptide at all. It's a small molecule that fits the same receptor, and it can be taken with or without food.
A few peptides do work by mouth, but they're the exception. For BPC-157 capsules, the FDA found no human data on what happens when it's swallowed.
Shots aren't tradition. They're chemistry. See how every peptide is delivered, at peplexicon.com.

Sources