What this is
A public testosterone pharmacokinetics plotter for trt.tru3.org. It covers the 13 testosterone forms used in TRT and related replacement (injectable esters, oral undecanoate, gel, suspension, sublingual base). It does not include other anabolic steroids, peptides, or SARMs. There is no login.
The concentration equations are a re-implementation of a widely used public piecewise model: linear rise to Tmax, then first-order elimination, with empirical Cmax-per-mg and form-specific multipliers (notably 0.33 for enanthate and 0.6 for cypionate). Dose is the labeled milligram amount; there is no molecular-weight conversion to testosterone base. Time is in days with 24 samples per day. The Y-axis is ng/dL.
This site is original software with a light professional interface. It is not SteroidPlotter, does not use their branding or packed front-end, and does not claim to be that service. PK constants are compiled from publicly cited clinical studies; the model is simplified and not a multi-compartment fit.
Free testosterone (Vermeulen)
Free T uses a Vermeulen-style quadratic (albumin association constants
3.6×104 and 1.45×10−4). There is no albumin lab field on
the plotter; when albumin is unknown, the population default
4.3 g/dL (43 g/L) is used, as in
standard clinical calculators (Vermeulen et al., 1999). Bioavailable T =
free × (N + 1), where N is the albumin-binding term
3.6e4 × albumin × 1.45e-4 with albumin in g/dL.
Typical adult-male reported free T is about 5.0–21.0 ng/dL (equilibrium dialysis / analog immunoassays). That band is drawn on the free-T chart as a reference for comparison with the Vermeulen estimate.
Reference lines
- Total T: 300.0–1000.0 ng/dL (common adult-male laboratory window; not a treatment target).
- Free T: 5.0–21.0 ng/dL typical reported free T, as above.
Frequencies
Intervals match common TRT practice, including every 3.5 days and a TRT-specific 2× / week, 3 days then 4 days (Monday / Thursday) option that is not a simple fixed interval.
Disclaimer
For education only. Not medical advice, not a prescription device, and not a substitute for laboratory monitoring or a clinician. Real-world levels depend on injection site, vehicle, SHBG, body composition, residual endogenous production, assay method, and adherence. Do not start, stop, or change testosterone therapy from this plot.