Semaglutide
Also sold as Ozempic, Wegovy, Rybelsus.
- Half-life
- 165 h
- Steady state
- ~34 d
- Class
- GLP-1
- Category
- GLP-1
Published population averages. Steady state is the usual five half-life rule of thumb, not a measurement. See peptide half-life, explained.
Overview
Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist originally developed for type 2 diabetes. It has gained widespread attention for its significant effects on weight loss and cardiovascular risk reduction. Marketed as Ozempic (diabetes) and Wegovy (obesity), it is administered via weekly subcutaneous injection.
How it works
Mimics endogenous GLP-1 by binding to GLP-1 receptors in the pancreas, brain, and gut. Enhances glucose-dependent insulin secretion, suppresses glucagon release, delays gastric emptying, and reduces appetite via hypothalamic signaling. The molecule is 94% homologous to native GLP-1 with a C-18 fatty diacid chain enabling albumin binding for extended duration.
Half-life and peak
Terminal half-life is approximately 7 days (~165 hours), supporting once-weekly dosing. Steady-state plasma concentration is reached after 4–5 weeks. Peak plasma levels (Tmax) occur 1–3 days post-injection.
What it is studied for
Glycemic control in T2DM, chronic weight management, cardiovascular outcome reduction (SUSTAIN, STEP, and SELECT trial programs).
Research status
FDA-approved for T2DM (Ozempic, 2017) and chronic weight management (Wegovy, 2021). Oral formulation (Rybelsus) approved 2019. SELECT cardiovascular outcomes trial (2023) showed 20% MACE reduction.
Sources
- Semaglutide — MedlinePlus Drug Info · medlineplus.gov
- SUSTAIN trials overview — PubMed · pubmed.ncbi.nlm.nih.gov
- STEP 1 weight loss trial — NEJM · doi.org
- SELECT cardiovascular outcomes — NEJM · doi.org
- Semaglutide PK profile — Clinical Pharmacokinetics · doi.org
- FDA prescribing info — Ozempic label · fda.gov
Educational reference only. This page describes what is published about a compound; it is not medical advice, not a recommendation to take anything, and not a dosing guide. Several compounds in this catalog are investigational and are not approved medicines. Talk to a doctor.
Guides that cover it
How to track a GLP-1 protocol properly
A weekly injection is easy to take and surprisingly easy to lose track of. What to record, why the date matters more than the dose, and how to keep a titration legible to the person who prescribed it.
Ozempic, Wegovy, Mounjaro, Zepbound: which is which
Four brand names, two molecules, and a lot of confusion. What each name actually refers to, why the same drug is sold twice under different labels, and what that means when you are keeping a record.
Peptide half-life, explained
Half-life is the number that decides how often something is injected, how long it takes to settle, and how long it lingers after you stop. Here is what it does tell you, and the three things people assume it tells them that it does not.