Legacy testosterone + hCG example

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: Population PK model derived from 31 healthy adult men; the display uses its typical fixed parameters rather than individual fitted parameters. Testosterone cypionate depot injection studied in the repeated-dose cohort analyzed by Bi et al.; Intramuscular. Fixed reference weight: 85 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 cypionate mg

Source exposure scope: The source cohort received 14 weekly injections in 100, 250 or 500 mg groups. Other scenarios are linear-model simulations, not additional observed regimens or recommendations.

Adult IM testosterone cypionate: injected-drug model component

bi-2018-cypionate-im-component · version 1

• Fixed reference covariates: baseline weight 85 kg, albumin 4.60 g/dL, weight change +2.90 kg and albumin change −0.20 g/dL; all covariate multipliers equal one.
• Zero individual random effects, zero initial exogenous amount and zero endogenous input for the isolated injected-drug component.
• Nominal testosterone cypionate mg enter the depot as in the authors’ code; apparent clearance and volume already reflect this convention. No extra 0.70 ester factor is applied.

Model structure

One compartment with absorption

Apparent clearance (CL/F)

108.5063 L/hour

Apparent central volume (Vc/F)

14449.6 L

Absorption rate (ka)

0.05088958 /hour

Input mass conversion

1 mg modelled mass per mg entered

• This mathematical component excludes endogenous testosterone. It is not a measured blood fraction and cannot be compared directly with a total-testosterone test or laboratory range.
• The original total-testosterone analysis used time-varying LH and covariates. The display does not reconstruct those inputs or predict hormone recovery or fertility.
• The reference population was healthy adult men, not a personalized hypogonadism model; other formulations, routes and populations may differ.
• Reproducing the published component is a numerical/source check, not new clinical validation or a dose-selection method.

• Bi et al. 2018 — population PK/PD model

  Supplementary Model Files, PK Model for Total Testosterone: CL/F 2.60415 kL/day, V/F 14.4496 kL, Ka 1.22135/day. This display isolates the linear injected-dose contribution and omits endogenous input.

Highly purified urinary hCG, Choriomon, subcutaneous injection. 24 healthy women aged 20–45 in a crossover pharmacokinetic analysis, with oral-contraceptive pituitary downregulation.

hCG: estimated concentration in serum (mIU/mL).

Calibration dose

10000 IU

Reported calibration peak

337.88 mIU/mL

Peak timing used

16 hours

Terminal half-life used

36.77 hours

Reconstructed absorption rate

0.1473787 /hour

• We reconstruct a one-compartment curve with first-order absorption and elimination from the reported peak, peak timing and terminal half-life; this is not a published fitted model.
• The reported terminal half-life is used as the elimination half-life; absorption rate is inferred from the 16-hour peak timing.
• Peak 337.88 IU/L at 10,000 IU is numerically 337.88 mIU/mL. The observed peak already includes absorption, so no additional bioavailability multiplier is applied.
• Concentration scales linearly with entered IU; overlapping dose contributions are added when accumulation is enabled. Zero pre-existing hCG is assumed.
• Applying this single-dose female study to men, other urinary products, lower doses or repeated schedules is an approximation, not verified equivalence.
• Recombinant Ovidrel/Ovitrelle and intramuscular administration are outside this calibration. Their dose units and product instructions remain separate.
• The curve estimates hCG, not testosterone, fertility, effectiveness, adverse effects or a suitable dose. Individual blood levels can differ substantially.
• The default amount is a plotting example. The study used one 10,000-IU dose; other amounts and schedules are extrapolations.

Older hCG entries interpret each legacy mg as 10,000 IU, matching the original CSV assumption. Confirm the IU amount; this is not a mass-to-IU or preparation conversion.

• Randomized urinary/recombinant hCG pharmacokinetic study (2022), Table 1

  Choriomon 10,000 IU SC, N=24 PK analysis: arithmetic mean Cmax 337.88 IU/L, median Tmax 16 h, mean terminal half-life 36.77 h, observed mean AUCinf 23,779.06 IU·h/L. Endpoints are from the same product arm.

• Trinchard-Lugan et al. 2002 — hCG pharmacokinetics

  Study linked in the supplied CSV. Its abstract supports first-order absorption/one-compartment modelling after extravascular recombinant hCG. Used for the approximate curve structure, not urinary-product parameter calibration.

Estimate hcg-urinary-sc-2022-endpoint-estimate · version 1