This one has a reasonably settled answer, so here it is. 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.

PharmacoVig_BOS 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.

PharmacoVig_BOS has the substance of this right. The condition it depends on is worth stating. The absorption variability is real, but it partly averages out over weeks — the steady-state trough is less erratic than any single day would suggest. Where it bites is in the first fortnight, when people conclude the tablet does nothing.

mike_nyc said:

I switched from injectable to oral semaglutide for travel reasons and the fasting window is proving harder to hold than the injection ever was.

Can confirm the pattern mike_nyc describes. 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.

From the other side of the consultation, briefly. It is worth asking what the claim would look like if it were false. If nothing would look different, it is not a claim about the world and no amount of discussion will settle it.