What is the half-life of semaglutide?
Semaglutide has a plasma half-life of approximately 7 days (~165 hours) in humans. The long pharmacokinetic profile derives from a C18 fatty-acid sidechain attached via a spacer that mediates reversible non-covalent binding to serum albumin in circulation. The ~7-day half-life is the basis for the once-weekly subcutaneous dosing schedule used across the SUSTAIN, STEP, and SELECT clinical-trial programs.
What the research literature says
Semaglutide’s pharmacokinetic profile was characterised across the clinical-development program that led to the compound’s regulatory approvals. The once-weekly dosing schedule used across the SUSTAIN type 2 diabetes program (SUSTAIN 1, PMID 28110911) and the STEP obesity program (STEP 1, PMID 33567185) is supported directly by the ~7-day plasma half-life. The cardiovascular-outcomes trial in type 2 diabetes (PMID 27633186) and the SELECT trial in obesity without diabetes (PMID 37952131) used the same dosing interval.
The albumin-binding sidechain is the engineering feature that drives the long half-life. Albumin binding sequesters the peptide in circulation, reduces renal clearance, and shields the molecule from proteolytic degradation. The same engineering strategy applied across the long-acting peptide-therapeutic class — tirzepatide uses a similar architecture, as do several other once-weekly GLP-1 agonists in development.
Beyond the half-life itself, the steady-state pharmacokinetics support continuous receptor engagement between weekly doses. After 4-5 weekly doses, plasma concentrations accumulate to a steady-state level that maintains GLP-1 receptor activation continuously, supporting the integrated metabolic effects (glucose-dependent insulin secretion, glucagon suppression, slowed gastric emptying, centrally-mediated appetite suppression) observed across the clinical programs.
Why this matters in research context
The long plasma half-life shapes both experimental dosing cadence and time-course sampling design for semaglutide research protocols. Acute single-dose pharmacology shows progressive accumulation to steady state over several once-weekly doses; washout from steady state similarly requires several weeks. Researchers designing semaglutide protocols typically account for this slow approach to and departure from steady state when interpreting time-course data and when planning crossover-design dose-comparison studies.
Related compounds
- Semaglutide 10mg — the compound covered by this answer
- Tirzepatide 10mg — parallel long-acting dual-incretin agonist (~5-day half-life)
- Semaglutide (glossary entry) — mechanism, pharmacology, clinical-trial overview
Related research questions
- What is the half-life of tirzepatide?
- How long does reconstituted semaglutide last?
- How much bacteriostatic water with semaglutide?
References
- Marso SP et al. Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes. N Engl J Med 2016;375(19):1834-1844. [PMID 27633186]
- Sorli C et al. Efficacy and safety of once-weekly semaglutide monotherapy versus placebo in patients with type 2 diabetes (SUSTAIN 1). Lancet Diabetes Endocrinol 2017;5(4):251-260. [PMID 28110911]
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med 2021;384(11):989-1002. [PMID 33567185]
- Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. N Engl J Med 2023;389(24):2221-2232. [PMID 37952131]
Research-questions pages describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. Semaglutide is sold strictly as a research-grade reagent for laboratory and bench research applications.