Legacy hCG + tamoxifen example

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

Label terminal 120–168 h;144 h midpoint is a timing assumption.

One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.

Timing half-life used

144 hours

Absorption half-life assumed

0.6364052 hours

Reference amount for the relative scale

1 mg

• The faster rate is inferred to match the 5 h source-scoped peak time; absorption half-life 0.6364052012164843 h is a mathematical shape parameter, not separately measured.
• A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
• One-compartment predicts steady mean 354.7 ng/mL (~2.91×122); biphasic parent kinetics and metabolites require more than aterminal exponential.
• Do not sum parent+N-desmethyl/endoxifen as equal drug action.
• Tablet dose is tamoxifen base equivalent, not mass of citrate salt.

• Tamoxifen citrate prescribing information

  20 mg single dose parentpeak 40 ng/mL at 5 h; terminal 5–7 days;20 mg/day chronic meanparent 122 ng/mL; N-desmethyl 353 ng/mL.

nolvadex-relative-timing-2026-10 · version 1