Anabolic Steroids/Hormones
Testosterone Cypionate
Also called Test Cyp · TC
Testosterone cypionate is used in TRT to restore testosterone and improve symptoms such as low sex drive in men with confirmed deficiency. Bodybuilders use higher amounts to pursue muscle and strength. Its gradual release makes injection frequency, changing symptoms and blood-test timing central practical questions.
Dosage & duration
Adult TRT examples. Amounts are testosterone-cypionate mg, not mL or the total content of a vial.
TRT: Endocrine Society starting examples
Published example · product-specific- Dose
- 75–100 mg per injection weekly, or 150–200 mg per injection every 2 weeks
- How often
- Into muscle: weekly or every 2 weeks, matching the dose above
- How long
- Ongoing replacement when indicated; no fixed cycle
Guideline examples for men with diagnosed testosterone deficiency. Dose and interval are adjusted to response and consistently timed blood tests.
Sources: 2
TRT: U.S. Depo-Testosterone label
Product label- Dose
- 50–400 mg per injection
- How often
- Into muscle, every 2–4 weeks
- How long
- Individualized ongoing treatment; no fixed label course
The label gives this broad range. It is not a weekly-dose range, and it is distinct from the guideline schedules above.
Sources: 1
These medical examples describe monitored treatment for testosterone deficiency. Neither a plotted curve nor a stated duration establishes a safe bodybuilding regimen or recovery date.
One dose · modeled timing
An injection rises, then gradually fades
100% = the model’s peak, not the dose left or a blood-test result.
About this curve
The medicine takes time to enter the bloodstream. This example makes that rise and fall easier to see.
- A delayed rise
- The line starts rising as testosterone from the injection reaches the bloodstream.
- Doses can overlap
- Another injection can add to what is still present. Explore schedules in the full plotter.
Study model · testosterone from injections only. Natural testosterone is excluded, so this is not a blood-test prediction. The research model and the label’s eight-day half-life describe different contexts.
Model assumptions and sourcesWhat people hope to gain
Bodybuilding discussions focus on muscle, strength and training drive. Some people report acne, water retention or feeling worse as well as better. TRT has a different aim: treating symptoms of confirmed testosterone deficiency, especially reduced sexual desire. Tiredness alone does not establish low testosterone.
Cypionate versus enanthate
Both supply testosterone; neither ester is a separate muscle-building hormone. Availability, injection comfort and the specific preparation help explain preferences. Reported comparisons may also involve changes in dose, carrier oil or other medicines, making the ester’s contribution hard to separate.
Check the vial concentration too: milligrams describe the amount of drug, while milliliters describe its volume.
Weekly or split injections?
Some users prefer fewer injections; others seek smaller fluctuations or fewer symptoms before the next one. In the plotter, dividing an equal weekly total reduces the model’s swings. That comparison does not prove better mood or fewer side effects, and more injections mean more preparation.
Blood-test timing also matters. Record the injection date and follow the prescriber’s testing plan. Comparing a result soon after an injection with one before the next can make a stable routine look inconsistent.
What the plot cannot answer
The curve estimates testosterone contributed by intramuscular injections and excludes natural production. It does not predict a total-testosterone blood test or decide whether treatment is working for an individual.
Follow-up includes blood pressure and blood counts, alongside symptoms such as acne, fluid retention or breast changes. Testosterone can reduce sperm production; a normal testosterone result does not confirm fertility. Discuss pregnancy plans before starting or changing treatment.
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.
Safety and interaction notes Read the limitations and discuss clinical questions with a professional
- Aromatizes
- Yes
- DHT derivative
- No
Common questions
Is twice-weekly cypionate always better than once weekly?
No. More frequent, smaller doses reduce the model’s swings when the weekly total stays the same, but add injections. Symptoms and measured blood levels guide an individual treatment plan; the chart cannot show that one schedule will feel better.
Can testosterone cypionate be injected under the skin?
The U.S. Depo-Testosterone label specifies injection into muscle. Under-skin use has also been studied, including a small study in transgender men, but that is a separate route and prescribing context. The curve here remains an intramuscular model.
Why do the label and guideline show different schedules?
The product label gives a broad dose-and-interval range. The Endocrine Society gives narrower weekly or every-two-week examples for replacement therapy. Neither is a personalized prescription; keep the amount, interval and product together.
Is 200 mg/mL the dose?
It is the concentration, meaning the amount in each milliliter. The prescribed dose is the number of milligrams to administer. Depo-Testosterone is supplied in more than one concentration, so the same volume can contain different amounts.
Sources Labels, studies and notes behind this guide
Summary and fact source checks: 2026-10-07, 2026-10-06. This records source checking, not medical review of the whole page.
Notes on the quick facts
- TRT goal
- Diagnosis combines symptoms with repeatedly low morning testosterone results. Low energy alone has many possible causes.
- Timing trade-off
- Longer gaps mean fewer injections. Smaller, more frequent doses at the same weekly total reduce the model’s peak-to-trough swing.
- Follow-up
- Feeling better does not show whether blood pressure or red blood cells have risen. Fertility plans also matter.
- 1. Depo-Testosterone — U.S. prescribing information
Full current label checked, revised September 2025. Male hypogonadism, intramuscular route, 50–400 mg every 2–4 weeks, 100/200 mg per mL strengths, blood-pressure and blood-count monitoring, reproductive and abuse-related risks. The label half-life does not calibrate this page’s separate research model.
- 2. Endocrine Society 2018 — testosterone therapy guideline
Tables 3, 5 and 9: symptom assessment; 75–100 mg weekly or 150–200 mg every two weeks for IM cypionate/enanthate; timed blood testing and monitoring. These are guideline examples, separate from the broad vial-label range.
- 3. Bi et al. 2018 — testosterone cypionate population model
Source for the existing adult IM injected-drug component. Natural testosterone and individual fitted effects are excluded; no model parameters were changed in this reader update.
- 4. Bi et al. 2018 — injected-dose model component
Single-dose shape computed with the existing linear injected-drug component at fixed reference covariates. Normalized to its own optimized peak; no endogenous contribution or lab-range comparison.
- 5. 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.
- 6. Bi et al. 2018 — adult IM testosterone cypionate population model
The injected-drug component uses published executable coefficients and nominal ester dose units. Endogenous testosterone and fitted individual effects are excluded.
- 7. Nankin 1987 — hormone kinetics after IM testosterone cypionate
Original abstract checked: 11 men with hypogonadism given 200 mg IM had testosterone peaks on days 2–5, followed by declining levels. This supports delayed peaks and variable blood-test timing; it is not this page’s model calibration.
- 8. McFarland et al. 2017 — subcutaneous testosterone cypionate
Small study of 11 transgender men receiving weekly SC cypionate. Establishes that this route has been studied, not that the present IM reference curve predicts SC treatment.
Keep reading
Related compounds and examples
Related compounds
Testosterone Enanthate
Testosterone enanthate is used to replace testosterone when low levels cause symptoms. Bodybuilders use higher amounts to pursue muscle and strength. The practical questions are how much is being used, how often to inject, and how the schedule affects peaks, troughs and treatment burden.
Testosterone Propionate
Testosterone propionate appeals to people who want testosterone with a shorter release profile. Bodybuilders seek muscle and strength; the everyday trade-off is frequent injections rather than a special kind of testosterone.
Testosterone Undecanoate (Castor Oil)
Long-acting testosterone undecanoate is used for TRT when fewer injection appointments are a priority. Nebido and Aveed can last many weeks between injections, but their doses and starting schedules differ.