TRT: Test Cyp 120mg — Weekly vs 2×/week (compare)
Compares 120 mg/week Testosterone Cypionate dosed once vs twice weekly.
Concentration over time
Model details: Testosterone Cypionate
How to read this chart
This is a study-based example of how testosterone levels change over time. Try different doses or timing to compare the curves.
The calculation uses the same assumptions for everyone. It can't predict your own blood levels or tell you what dose to take.
Only testosterone from the entered doses is shown. Your body's own production isn't included, so this isn't your total blood level.
Study setup and sources
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.
| Date | Testosterone Cypionate · Testosterone from entered doses only (ng/dL) |
|---|---|
| W1 | 0 ng/dL |
| W2 | 1121.55 ng/dL |
| W3 | 1032.51 ng/dL |
| W3 | 1109.37 ng/dL |
| W4 | 1132.19 ng/dL |
| W5 | 1129.67 ng/dL |
| W6 | 1035.16 ng/dL |
| W7 | 1123.51 ng/dL |
| W8 | 1211.45 ng/dL |
| W9 | 1238.93 ng/dL |
| W10 | 1292.25 ng/dL |
| W11 | 1352.39 ng/dL |
| W12 | 1358.7 ng/dL |
The chart uses a bounded time grid. Long horizons can miss brief peaks between samples; shorten the horizon to inspect more detail. Chart peaks are sampled values.
Protocol summary
TRT: Test Cyp 120mg — Weekly vs 2×/week (compare) · 12 weeks starting Oct 30, 26
- Testosterone Cypionate — 120.0 mg Every 7 days, weeks 0–12
- Testosterone Cypionate — 60.0 mg 2×/week (Mon/Thu), weeks 0–12
Protocol overview
- Category
- trt hrt
- Duration
- 12 weeks
- Compounds
- 2
- Tags
- trt, compare, cypionate
Compounds in this protocol
- Test Cyp 120mg once weekly — 120 mg, every-7-days
- Test Cyp 60mg twice weekly — 60 mg, 2x-per-week
How to read this protocol
The chart shows available model curves over the 12-week example. Rows whose model is unavailable are retained for context but produce no curve. Read each model’s details for what its line represents; a plotted level does not predict treatment effects or establish a suitable dose.
The peak/trough explorer examines one complete model interval. The single-dose decline explorer is a separate one-dose scenario; it does not calculate this protocol's washout or a safe treatment-change date. Read the recovery reference for PCT evidence and its limits.
Educational only. Not medical advice. These examples do not predict individual blood levels.