Dose Interval
Visualizer
Enter a half-life and how often you dose. See whether repeated doses build up over time, how high the plateau sits above a single dose, and how long steady state takes to reach.
Schedule
Accumulation ratio
Levels plateau at about twice a single dose.
How this works
Methodology reviewed July 2026The tool treats each dose as a pulse that clears by first-order decay, then adds the surviving remnants of every past dose together — the superposition principle that underlies steady-state pharmacokinetics. From the half-life it derives λ = ln(2)/t½ and the fraction surviving one interval, e^(−λτ). The accumulation ratio, the plateau's height relative to a single dose, is 1/(1 − e^(−λτ)); the steady-state trough is that ratio scaled by one interval of decay, and the peak is one dose higher than the trough. Because the approach to plateau follows 1 − e^(−λt), steady state is effectively reached after roughly four to five half-lives no matter how often you dose. The curve is a direct simulation of the summed doses over time.
λ = ln(2) / half_life
survives_interval = e^(−λ·τ) (τ = dosing interval)
accumulation_ratio = 1 / (1 − e^(−λ·τ))
steady_trough = R × e^(−λ·τ) (in units of one single-dose peak)
steady_peak = steady_trough + 1
time_to_fraction f = −ln(1 − f) / λ
Half-life · Dosing interval
Accumulation ratio · Steady-state peak · Steady-state trough · Peak-to-trough swing · Time to ~90% and ~97% of steady state
- Every dose is identical and taken exactly on schedule with no missed or doubled doses.
- Absorption is instantaneous, so each dose is modeled as an immediate jump followed by first-order decay.
- Clearance is mono-exponential with a constant half-life across the concentration range.
- Levels are expressed relative to a single dose's peak (a single first dose peaks at 1.0), not in absolute concentration units.
- Real absorption is gradual, so actual peaks are lower and later than the instantaneous jumps drawn here, and troughs are smoothed.
- The model ignores multi-compartment distribution, non-linear (saturable) clearance, and any change in half-life with dose or over time.
- It shows relative accumulation, not absolute blood levels, and says nothing about what concentration is effective or safe.
- Missed doses, dose changes, and loading doses all break the identical-dose assumption and are not represented.
- Accumulation math describes how levels stack, not whether any interval or dose is appropriate; it is not a dosing schedule.
- A high accumulation ratio is a reason to understand a compound's kinetics with a clinician, not a target to pursue.
- Many research peptides are not approved for human use and have poorly characterized kinetics; this model is for education only and not a recommendation to obtain, prepare, or use any compound.
This calculator is for educational purposes only and is not medical advice, diagnosis, or treatment. Results are estimates based on published formulas and population averages — your individual values may differ. Nothing here is calculated on a server: everything runs in your browser and no data is stored or sent anywhere. Always consult a qualified clinician before making health, medication, or training decisions.