Answering the narrow version, because the broad one does not have a single answer. 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.

amsterdam_pete 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.

That is correct as far as it goes, and here is where it stops going. 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:

On 25mg oral, four months in, and my results are closer to the low-dose injectable arm than to the numbers being quoted for 50mg.

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.

Clinical perspective, offered as context rather than as advice. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.