Route of Administration
Oral
Last updated
Swallowed, and absorbed from the gastrointestinal tract. Most peptides fare badly here, because stomach acid and digestive enzymes break the chain apart, so the fraction reaching the circulation intact is often a small fraction of one per cent unless the product includes an absorption enhancer or the molecule is a small molecule rather than a peptide. Capsules and tablets are dosage forms that use this route.
Why it matters here
Route sets what a milligram means. An oral figure and an injected figure for the same compound are not comparable amounts, and treating one as the other is one of the commonest ways a record gets misread.
What it is not
Oral is not Sublingual: a liquid held under the tongue is being used sublingually, and swallowing the same liquid sends it through the gut instead, with a very different fraction absorbed.
Also called
- oral
- po
- by mouth
- capsule
- tablet
PO comes from the Latin per os, by mouth. Capsule and tablet are dosage forms rather than routes, and they are indexed here because that is what people search for.