Last updated: May 2026
The InjectBuddy cycle plotter models serum blood levels for injectable steroids and TRT compounds over a full cycle using pharmacokinetic (PK) mathematics. Select a compound, enter your dose and injection frequency, and the graph updates instantly to show your peak and trough levels, time to steady state, and washout period.
The plotter uses a one-compartment model with first-order absorption and elimination. Each injection is modelled independently using the formula C(t) = dose × ka/(ka − ke) × (e−ke×t − e−ka×t), where ke is the elimination rate constant (derived from half-life: ke = ln(2) / halfLife) and ka is the absorption rate constant (solved numerically from Tmax using a bisection algorithm). All injections in the cycle are summed to produce the accumulated blood level curve.
Phase 1 includes 11 injectable compounds across four categories: testosterone esters (enanthate, cypionate, propionate, undecanoate), nandrolone esters (NPP, Deca), trenbolone (acetate, enanthate), and other common injectables (Boldenone Undecylenate / EQ, Masteron Propionate, Masteron Enanthate).
Steady state is the point at which blood levels stabilise — this occurs at approximately 4.3 half-lives after the first injection. For testosterone enanthate (half-life ~4.5 days), steady state is reached around day 19. Washout — the point at which levels drop to ~1% of peak — is approximately 4.3 half-lives after the final injection.