Collecting this in one place because it comes up every few weeks and the answer is always assembled from scratch. It is about oral semaglutide, and it is deliberately narrow — everything I am not confident about is marked as such.
What is actually established
Oral semaglutide is absorbed in the stomach with the help of SNAC, which locally raises pH and protects the peptide long enough to cross. That mechanism is fragile: bioavailability is roughly 1% and highly sensitive to gastric contents, so a mouthful of coffee genuinely changes the exposure. This is why the label wants 30 minutes and no more than half a glass of plain water.
The condition it depends on
Worth adding that the tablet is taken daily, so a missed dose costs far less than a missed weekly injection. That is a genuine advantage nobody lists.
The practical version
The practical numbers: about 1% oral bioavailability, 30 minutes fasted before food, no more than 120ml of plain water, and coffee counts as food for this purpose.
What I am not sure about
What I am after is how much of the oral variability is the SNAC absorption window and how much is dose, because the two get conflated constantly. If the honest answer is that nobody knows, that is a useful answer and I would rather have it.
BiostatsBrad said:Oral semaglutide is absorbed in the stomach with the help of SNAC, which locally raises pH and protects the peptide long enough to cross.
Agreeing with BiostatsBrad, and the qualification matters more than the agreement. Orforglipron is the more interesting oral story because it is not a peptide at all. Being a small molecule it does not need SNAC, does not need the fasting window, and has oral bioavailability in the tens of percent rather than about one.
BiostatsBrad said:Oral semaglutide is absorbed in the stomach with the help of SNAC, which locally raises pH and protects the peptide long enough to cross.
I do not accept that the fasting window is a minor inconvenience. Adherence data on daily orals with timing requirements is consistently worse than weekly injections, and a drug you take imperfectly is a lower dose than the one on the box.
Sigma-Aldrich — Research-Grade Standards
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Shop Reference StandardsThis one has a reasonably settled answer, so here it is. The OASIS programme put 50mg oral in the same territory as 2.4mg injectable — around 15% mean weight loss — but it needed a dose 20 times larger to get there because almost none of the tablet is absorbed. The dose numbers are not comparable across routes and quoting them side by side confuses people.
pete_manc_UK said:Orforglipron is the more interesting oral story because it is not a peptide at all.
Mine went the same way, slower. The detail I would add is minor and it is already implied above.