Free Online Tool
Peptide Serum Level Visualizer
See how your serum levels build up over 60 days of repeated dosing. Enter your dose, injection interval, and half-life to visualize the pharmacokinetic curve and find your steady state.
Avg Level at Day 30
203.48 mg
Avg Level at Day 60
206.49 mg
Stable (±10%) from
Day 11
Understanding Pharmacokinetics
Every time you inject a peptide, hormone, or other compound, it enters your bloodstream and immediately begins to decay following exponential elimination kinetics. The formula is: C(t) = C₀ × 0.5^(t / t½)
With repeated dosing at fixed intervals, each new injection adds to the remaining concentration from previous doses. This creates an accumulation effect — over time, the peak and trough levels rise until they stabilize at a steady state.
The “Exact” view shows the raw serum curve with each peak and trough visible. The “Average” view applies a moving average to smooth the data, showing the effective steady-state concentration your body maintains between injections.
Common Half-Lives Reference
| Compound | Half-Life | Typical Dose |
|---|---|---|
| BPC-157 | ~2 hours | 250-500 mcg |
| Semaglutide | ~7 days | 0.25-2.4 mg |
| Tirzepatide | ~5 days | 2.5-15 mg |
| Retatrutide | ~6 days | 1-12 mg |
| Testosterone Cypionate | ~8 days | 100-200 mg |
| Testosterone Enanthate | ~4.5 days | 100-200 mg |
| HGH (somatropin) | ~3 hours | 2-4 IU |
| CJC-1295 (DAC) | ~8 days | 1-2 mg |
| Ipamorelin | ~2 hours | 200-300 mcg |
Frequently Asked Questions
- What is a serum level visualizer?
- A serum level visualizer models how a substance accumulates in your bloodstream over time based on repeated dosing. It uses pharmacokinetic principles — specifically the half-life of the compound — to calculate how blood concentration rises, peaks, and stabilizes.
- What is half-life and why does it matter?
- Half-life (t½) is the time it takes for the concentration of a substance in your blood to decrease by 50%. A short half-life (e.g., 2 hours for BPC-157) means the peptide is eliminated quickly, requiring more frequent dosing. A long half-life (e.g., 6 days for Retatrutide) means levels accumulate significantly over multiple doses.
- What does 'steady state' mean?
- Steady state occurs when the amount of substance entering the bloodstream per dose equals the amount being eliminated. At this point, peak and trough levels stabilize within a consistent range (typically ±10% variation). Most substances reach steady state after approximately 4-5 half-lives of repeated dosing.
- How accurate is this calculator?
- This calculator uses a standard one-compartment pharmacokinetic model with first-order elimination kinetics. It provides a reliable approximation for most peptides and hormones. However, individual absorption rates, body composition, injection site, and metabolism can all affect actual serum levels.
- Can I use this for testosterone, GH, or other hormones?
- Yes. The calculator works for any substance where you know the dose and half-life. Common examples include Testosterone Cypionate (t½ ≈ 8 days), Testosterone Enanthate (t½ ≈ 4.5 days), HGH (t½ ≈ 3 hours), and various peptides like BPC-157, Semaglutide, or Tirzepatide.
Need to calculate how much to draw from your syringe?
Try the Reconstitution Calculator →