Can peptides be taken orally?

The approved oral peptides

• Semaglutide: Rybelsus, Ozempic tablets and Wegovy tablets, with an absorption enhancer (SNAC) and estimated bioavailability of 0.4–1% or 1–2% by label.
• Desmopressin: DDAVP tablets, about 0.16% of an intravenous dose by label, and the Desmoda oral solution, also 0.16%.
• Octreotide: Mycapssa delayed-release capsules, whose label reports peak levels 33% lower than a subcutaneous dose and requires an empty stomach.
• Linaclotide (Linzess) and plecanatide (Trulance): both labels describe minimal absorption with negligible systemic availability, because both act on a receptor in the intestine.

Three ways an oral peptide works around digestion

The first is an absorption enhancer. The semaglutide tablets carry SNAC, which a 2018 study found buffers the stomach next to the tablet and briefly opens a route across its lining. The second is formulation: Mycapssa is a delayed-release capsule, and its label lists sodium caprylate among the ingredients. The third is not needing the blood at all. Linaclotide and plecanatide bind a receptor on the inner surface of the intestine, so being poorly absorbed is part of how they work.

All three still pay in dose. By Prof. Peptide's arithmetic from the two DDAVP labels, the tablet's starting daily amount is roughly 25 to 50 times the injection's, and the semaglutide tablets run at milligram doses several dozen times the weekly injection.

How the semaglutide tablets compare with the injection, label by label, is set out in semaglutide pills vs injection.

What human studies show for research peptides by mouth

A handful of growth-hormone secretagogues were tested orally in people in the 1990s. In a 1994 study of hexarelin in 12 volunteers, the authors estimated biological bioavailability, from the growth-hormone response, at 0.3% by mouth against 77% by subcutaneous injection. For GHRP-6, a 1999 study found no change in growth hormone after enteric-coated capsules, while two earlier studies reported oral GHRP-6 raising it.

AOD-9604 is the one research peptide with a sizable oral human program: four of six randomized trials summarized in a 2013 paper gave it as capsules or tablets, the largest to 502 adults over 24 weeks. That paper reports safety results only. Glutathione, a three-amino-acid peptide sold as a supplement, has oral trials with conflicting results. MK-677, often grouped with these compounds, is an oral drug in trials but is not a peptide.

For BPC-157, KPV, TB-500, epitalon and most other compounds sold as capsules, no human study of an oral form has reported results. The record is animal work, or nothing.

For the evidence status of every oral form on this site, compound by compound, see which peptides come in pill form.