Tool
Peptide half-life calculator
Given a peptide's half-life and a dosing interval, calculate the steady-state concentration ratio. Pure pharmacological math for UK research-peptide context. Not a dosing recommendation. Reference the peptide's specific half-life from the published preclinical literature, not from this tool.
Half-life values for specific peptides should be drawn from the published preclinical or clinical literature for that compound. Reference the encyclopedia entry per compound. Note: CJC-1295 without DAC has minutes-scale half-life; with DAC has roughly 6-8 day half-life. Tesamorelin half-life is around 30 minutes IV, longer SC. BPC-157 half-life data is sparse.
The math
- · Fraction remaining = (1/2)^(interval / half-life). First-order elimination assumption.
- · Steady-state accumulation ratio = 1 / (1 − fraction remaining). Ratio of steady-state trough to single-dose trough.
- · Time to 95% steady state ≈ 4.32 × half-life. Five half-lives reaches 96.875% by convention.
Half-life pharmacology is the same math whether you are reasoning about BPC-157, semaglutide, or paracetamol. The tool does not encode any peptide-specific logic. It is reference math.
| Step | Value |
|---|---|
| Half-life (hours) | 4 |
| Dosing interval (hours) | 24 |
| Fraction remaining at next dose | 1.6% |
| Steady-state accumulation ratio | 1.02x |
| Time to 95% steady state | 17.3 hours |
Source: Standard first-order elimination math, applied to the calculator's default inputs
Illustrative only, computed from the default inputs and the formulas above. Adjust the calculator for any compound's published half-life. This is reference pharmacology, not a dosing recommendation, and not medical advice.
View as plain-text Markdown
### Worked example: 4-hour half-life, 24-hour interval (default calculator inputs) | Step | Value | | --- | --- | | Half-life (hours) | 4 | | Dosing interval (hours) | 24 | | Fraction remaining at next dose | 1.6% | | Steady-state accumulation ratio | 1.02x | | Time to 95% steady state | 17.3 hours | Source: Standard first-order elimination math, applied to the calculator's default inputs Illustrative only, computed from the default inputs and the formulas above. Adjust the calculator for any compound's published half-life. This is reference pharmacology, not a dosing recommendation, and not medical advice.
“This is general pharmacokinetic math, not a guide to any specific peptide. Published half-life data for research peptides is often sparse or animal-only, and a single half-life figure can hide wide variation between individuals and routes. Treat any output as a rough reference for understanding accumulation, not as a dosing schedule, and do not read a health or safety claim into it.”