The oral peptide problem
Peptides are normally destroyed in the gut, which is why almost every peptide drug is injected. Amycretin's oral tablet…
How a peptide becomes a pill
Peptides are normally destroyed in the gut, which is why almost every peptide drug is injected. Amycretin's oral tablet is unusual because it uses the SNAC absorption enhancer, the same technology that made oral semaglutide (Rybelsus) possible, to sneak a small fraction across the stomach wall.
This unit explains why oral peptides are so hard, how SNAC solves part of the problem, the strict conditions that come with it, and where oral amycretin fits in the race for a convenient weight-loss pill.
Key terms
Why peptides fail in the gut
The gut is built to digest proteins and peptides, so swallowing a peptide drug normally destroys it. Stomach acid and digestive enzymes chop it up, and even intact peptides are too large and water-loving to cross the gut wall. This is why insulin, GLP-1 drugs, and most peptides are injected.
Two problems compound each other: destruction by acid and enzymes, and poor crossing of the gut wall. Solving only one is not enough. An oral peptide drug needs a way to protect the molecule and help it across at the same time, which is precisely what the SNAC platform is designed to do.
AdvancedWhy peptides cannot simply be coated to survive
Enteric coatings protect some drugs from stomach acid, but they do not help a peptide cross the gut wall, the second, harder problem. A peptide is large and hydrophilic, so it cannot slip between or through gut cells on its own. That is why oral peptide delivery needed a genuine absorption enhancer, not just a protective shell, and why it took decades to achieve even for a single molecule like semaglutide.