Peptide Half-Life & Accumulation Calculator
See how a compound builds toward steady state across repeated doses — and roughly where your level sits between injections.
Your protocol
72 h
2.0 mg
84 h
28 days
Estimated blood level
relative units · first 28 days
Steady state
≈ 1.8× single dose
Day 0Day 7Day 14Day 21Day 28
Doses to ~95% steady
4
Peak : trough ratio
2.24 : 1
Time to steady
14 d
⚠︎A simplified pharmacokinetic model for education — real absorption varies by compound, ester and individual. Not medical advice.
How this works
Each dose decays exponentially. After time t, a single dose has fallen to a fraction set by its half-life:
level = dose × (½)t / half-life
When you dose again before the previous one clears, the leftovers stack. Summing that decaying series gives the accumulation factor at steady state:
accumulation = 1 / (1 − (½)interval / half-life)
Shorter intervals relative to the half-life mean more accumulation and steadier levels. We show the math because a tool you can't audit isn't one you should trust with your health.