After a substance is given, blood samples are taken at different times and the concentration curve is plotted. Three numbers that appear in almost every pharmacokinetic study come from it:
- Cmax: the maximum concentration reached. It relates to effects that depend on the peak.
- Tmax: the time taken to reach that peak. It shows the rate of absorption; it is short by the intravenous route and longer by the subcutaneous route or with lipidated molecules.
- AUC: the area under the curve, that is, total exposure over time. It is the parameter used to calculate bioavailability by comparing routes.
Together with half-life and clearance, these values make it possible to compare formulations, routes of administration and analogues of the same hormone.
Why it matters in peptide research
Two compounds can have the same AUC with very different Cmax, or the other way round. Looking only at the “total amount” without the shape of the curve leads to misleading comparisons.
Related terms
Learn it in depth at the Peptide University
- Pharmacokinetics: ADME and parameters · Module 2
Definition for educational and scientific purposes. It is not medical advice or a recommendation for use. NeoPeptidos products are sold labelled for research use only (RUO).