Half-Life & Blood Concentration Visualizer

This tool uses a one-compartment pharmacokinetic model with instantaneous absorption. After each dose, the drug concentration decays exponentially according to:

C(t) = Σ dose_i · e^{−k · (t − t_i)}

where k = ln(2) / halfLife is the elimination rate constant, and the sum is taken over all doses administered at times ti before the current time t.

With repeated dosing at fixed intervals, concentrations accumulate toward a steady state. The steady-state peak is dose / (1 − e−kτ) and the trough is dose · e−kτ / (1 − e−kτ), where τ is the dosing interval.

Time to reach approximately 90% of steady state is 3.32 × t½ (derived from log₂(10) × half-life).

One-compartment models are a simplification. Real pharmacokinetics involve multiple phases: absorption from the injection site, distribution into tissues, metabolism, and elimination. Many peptides exhibit multi-compartment kinetics.

This model does not account for:

• Absorption phase (assumes instantaneous absorption)
• Distribution into deep tissue compartments
• Receptor binding or target-mediated drug disposition
• Individual variability (body weight, renal function, age)
• Drug-drug interactions
• Body composition differences
• Non-linear pharmacokinetics (saturable metabolism)

Use this visualization for educational purposes and general pattern understanding only. It is not a clinical prediction tool. Actual plasma levels require blood sampling and assay measurement.