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testosterone: exogenous contribution in serum (ng/dL).

The body's own testosterone is excluded. This is the contribution from entered doses, not the total blood level.

Fixed reference profile: Ten adult men with hypogonadism already receiving IM testosterone enanthate; adult model reanalysis of the 2015 cohort. Testosterone enanthate 200 mg/mL in sesame oil (West-Ward), as studied in the IM reference cohort.; Intramuscular. Fixed reference weight: 90.35 kg.

Changing dose or schedule explores a scenario; it does not personalize the reference profile or establish a studied regimen.

Input dose basis: Nominal testosterone enanthate mg

Source exposure scope: The adult IM source cohort received a 200 mg study injection on existing treatment. Other schedules are simulations under fixed linear parameters, not additional observed regimens.

Adult IM testosterone enanthate: injected-drug model component

vogiatzi-2023-enanthate-im-component · version 1

• Published adult fixed-effect parameters; no individual random effects or pediatric allometric scaling.
• Zero initial exogenous amount and no endogenous testosterone contribution. Prior treatment is included only when its dose events are entered.
• Nominal testosterone enanthate dose enters the model directly; no additional ester-mass or bioavailability multiplier.

Model structure

One compartment with absorption

Apparent clearance (CL/F)

50.569 L/hour

Apparent central volume (Vc/F)

13755.8 L

Absorption rate (ka)

0.0831 /hour

Input mass conversion

1 mg modelled mass per mg entered

• This mathematical injected-drug component is not a measured fraction of an individual blood sample or a prediction of total testosterone.
• The small source cohort had prior treatment and variable endogenous testosterone. Clinical effects, endogenous recovery and fertility are not modeled.
• These IM parameters do not describe subcutaneous autoinjectors, other formulations or pediatric patients.
• Changing a simulated dose or interval does not establish treatment suitability, a testing date or an expected change in adverse effects.

• Vogiatzi et al. 2023 — adult IM population model

  Adult one-compartment model; pediatric simulations in the paper are not implemented.

• Vogiatzi et al. — supplementary Table 3 and Figures 7–8

  Full-precision IM fixed effects: Ka 0.0831/h, V 13755.8 L, CL 50.569 L/h. Figure 8 includes different initial endogenous levels, excluded from this component.

• Kaminetsky et al. 2015 — underlying clinical cohort

  The IM sesame-oil reference arm is separate from the subcutaneous autoinjector arms; observed total-testosterone endpoints are not isolated-dose peaks.

4 mL arachis-oil phenylpropionate preparation. IM gluteal. 7 healthy adult men in this cohort.

Nandrolone: estimated concentration in plasma (ng/dL).

Table 4 empirical peak/time with reported absorption half-time.

Calibration dose

100 mg

Reported calibration peak

847.896 ng/dL

Peak timing used

24 hours

Terminal half-life used

57.6 hours

Reconstructed absorption rate

0.1004466 /hour

• No extra F/ester correction; 100 mg ester already linked to observed nandrolone.
• Nominal nandrolone phenylpropionate ester mass
• Dose scaling and repeated-dose superposition use fixed parameters; the example dose does not calibrate the curve.
• Endpoint-calibrated first-order reconstruction, not the paper's fitted population model.
• Injection volume/site/oil change exposure; output fixed to the stated gluteal/arachis formulation.
• Absorption-limited terminal shape is not free-nandrolone elimination. Dose scaling and repeated-dose accumulation are estimates.
• The slow rate describes depot absorption-limited persistence, not free-nandrolone elimination. The inferred fast rate is a curve-shape parameter, not measured absorption.

• Minto 1997 nandrolone esters, Table 4

  100 mg ester IM: NPP 4 mL gluteal 30.9 nM/1 day; decanoate 1 mL gluteal 15.8 nM/2.4 days. Absorption halves 2.4/7.7 days.

Estimate nandrolone-phenylpropionate-source-estimate-2026-10 · version 1

1 mL arachis-oil decanoate preparation. IM gluteal. 5 healthy adult men in this cohort.

Nandrolone: estimated concentration in plasma (ng/dL).

Table 4 empirical peak/time with reported absorption half-time.

Calibration dose

100 mg

Reported calibration peak

433.552 ng/dL

Peak timing used

57.6 hours

Terminal half-life used

184.8 hours

Reconstructed absorption rate

0.04801302 /hour

• No extra F/ester correction; 100 mg ester already linked to observed nandrolone.
• Nominal nandrolone decanoate ester mass
• Dose scaling and repeated-dose superposition use fixed parameters; the example dose does not calibrate the curve.
• Endpoint-calibrated first-order reconstruction, not the paper's fitted population model.
• Injection volume/site/oil change exposure; output fixed to the stated gluteal/arachis formulation.
• Absorption-limited terminal shape is not free-nandrolone elimination. Dose scaling and repeated-dose accumulation are estimates.
• The slow rate describes depot absorption-limited persistence, not free-nandrolone elimination. The inferred fast rate is a curve-shape parameter, not measured absorption.

• Minto 1997 nandrolone esters, Table 4

  100 mg ester IM: NPP 4 mL gluteal 30.9 nM/1 day; decanoate 1 mL gluteal 15.8 nM/2.4 days. Absorption halves 2.4/7.7 days.

Estimate nandrolone-decanoate-source-estimate-2026-10 · version 1