Protokol Lab ships pharmacokinetic defaults for every FDA-approved GLP-1 receptor agonist. Each built-in compound carries published peer-reviewed PK values so dose curves are accurate from the first injection — not a generic decay line.
| Compound | Brand names | Half-life (t½) | Route | Typical interval |
|---|---|---|---|---|
| Tirzepatide | Mounjaro, Zepbound | ~5 days | Sub-Q | Weekly |
| Semaglutide | Ozempic, Wegovy | ~7 days | Sub-Q | Weekly |
| Semaglutide (oral) | Rybelsus | ~7 days | Oral | Daily |
| Liraglutide | Saxenda, Victoza | ~13 hours | Sub-Q | Daily |
| Dulaglutide | Trulicity | ~5 days | Sub-Q | Weekly |
Compounded tirzepatide and compounded semaglutide from a licensed compounding pharmacy contain the same active peptides as the brand-name versions. Use the built-in Tirzepatide or Semaglutide preset — the half-life, kinetic shape, and dose-to-active-level math are identical. Record your prescribed mg per injection, not the pen or vial label.
For any compound outside the FDA-approved list — for example, a substance prescribed under a clinical trial, an investigational formulation, or a compounded mix with non-standard concentrations — users can add a custom compound by entering a name and a half-life.
Protokol Lab does not publish pharmacokinetic defaults for compounds that are not FDA-approved. Users supply their own values and assume full responsibility for the accuracy of those values and for the legality of any substance they choose to track. Protokol Lab does not sell, ship, distribute, refer users to, or endorse any pharmacy, telehealth provider, or compounding facility for any substance.
Every dose is modeled with the Bateman equation — the standard two-compartment pharmacokinetic model for extravascular absorption. For subcutaneous peptides, the kinetic shape is a rise over a few hours (absorption rate ka) followed by first-order elimination at the compound's half-life.
When you stack multiple doses of the same compound, or run multiple compounds simultaneously, curves are summed correctly so the active level at any point in time reflects the full schedule — not just the most recent injection.