Research-literacy siteEducational evidence reviews only — not medical advice, not dosing guidance, not a protocol for human or animal use. Medical disclaimer.

PeptideStacks

Peptide Half-Life Visualiser

Pick a peptide and see its first-order plasma decay curve, based on the literature half-life reported on its monograph.

Educational only. Not a personalised PK model. Not for planning administration.

Kisspeptin-10 — literature half-life ~4 min plasma; intermittent dosing for pulsatile research (0.07 h parsed). Curve shows first-order elimination over 5 half-lives (≈20 min).

0%25%50%75%100%1× t½2× t½3× t½4× t½5× t½

First-order plasma decay is a simplification. Real peptide PK is often multi-compartmental, tissue-buffered, and dose-dependent (saturation, receptor binding, fatty-acid depot effects). This visualiser is for interpreting reported half-lives on published trials, not for predicting individual PK.

What the curve does and doesn’t model

The plotted curve is first-order plasma decay: concentration halves every t½ interval, and after five half-lives it’s under 4% of the peak. Reading the curve tells you how quickly a compound leaves plasma, and by extension how frequently a study protocol has to redose to keep circulating concentration above the pharmacological threshold.

It does not model:

  • Multi-compartment PK — most peptides show a rapid α (distribution) phase followed by a slower β (elimination) phase; single-t½ approximations undersell the tail.
  • Tissue reservoirs — BPC-157, thymosin β4 and other peptides accumulate in fascia / connective tissue with clearance kinetics unlike plasma.
  • Dose-saturation — receptor binding, protein binding, and enzyme saturation all become nonlinear at higher doses.
  • Depot-formulated peptides — fatty-acid conjugation (semaglutide, tirzepatide, cagrilintide) creates absorption-limited flat plasma profiles very different from IV administration.
  • Route of administration — the half-lives quoted are broadly published values; specific routes (SC vs IV vs IN) can shift them substantially.

Where the numbers come from

Every value plotted is copied verbatim from the peptide’s on-site monograph, which cites the published PK study. If a half-life on the curve looks wrong, the fix goes in the peptide’s frontmatter, not here.