Topic summary

Coming back to: Half-life, steady state, and accumulation worked through

Pharmacology › Pharmacokinetics tirzepatide liraglutide worked example semaglutide

This is a generated summary. It shows the 5 most-liked posts from a topic of 19, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

s.dziedzicTL2 Moderator7 Apr 2026 · edited#8

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

18 likes 4mo

compounding_ruthTL4Pharmacist8 Apr 2026 · edited#9

Albumin binding: semaglutide binds albumin through a fatty side chain, which sequesters the free form and extends the half-life. Tirzepatide also has albumin binding (different mechanism) which extends its half-life compared to an unmodified peptide.

19 likes 4mo

ma.balogunTL2 Moderator10 Apr 2026#11

a.silva, post #3: Hepatic metabolism: the degree to which each compound is hepatically metabolised versus renally cleared is known but varies. Severe liver disease changes clearance. Go to post

Worth separating two things that post #7 runs together.

SNAC (the oral bioavailability enhancer): sodium N-(8-[2-hydroxybenzoyl]amino) caprylate transiently raises gastric pH and promotes absorption. Without it, oral bioavailability is too low for clinical use. With it, bioavailability is still variable between people.

22 likes in reply to #3 4mo

d.nilsenTL2 Moderator13 Apr 2026#15

va.baptista, post #6: Coming back to post #4, because the follow-up matters more than the original answer. Half-life: semaglutide ≈ 165–184 hours (about a week). Tirzepatide ≈ 5 days. Liraglutide ≈ 13 hours. The half-life determines how much accumulation happens at steady state and how long it takes to clear after stopping. Go to post

On post #11 — agreed on the reasoning, with one qualification.

Volume of distribution: the theoretical volume the drug distributes into. For albumin-binding compounds, volume is reduced compared to drugs that do not bind protein. That is relevant to understanding how much free drug is available.

16 likes in reply to #6 3mo

OTeixeiraTL3Regular16 Apr 2026#18

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

31 likes 3mo

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Coming back to: Washout: how long is long enough, and for what purposePharmacology › Pharmacokinetics · 139 replies

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