Short answer: with regular dosing, levels reach steady state after about 4 to 5 half-lives, whatever the dose: 50% after 1 half-life, 90% after 3.3 and 97% after 5. Testosterone cypionate (half-life about 8 days) takes about 40 days (~5.7 weeks); tirzepatide (about 5 days) about 25 days (~3.6 weeks). Shorter intervals give a smaller peak-to-trough swing.
Counted like the app does for oil injections into muscle: what is still in the injection depot plus what is in blood, so the modeled total is highest right after each shot. The comparison line uses the same total per week, split differently.
Testosterone Cypionate: half-life, peak and steady state, with sources
Runs entirely in your browser; nothing you enter is sent anywhere. Modeled estimates, not measured levels, and not medical advice.
Each compound below has a half-life we checked against its FDA label or a published human study. Steady state is 5 half-lives of regular dosing. Click through for a chart, a peak-to-trough table and the sources.
| Compound | Half-life | Time to peak | Steady state after |
|---|---|---|---|
| Semaglutide | 7 days | 2 days | 5 weeks |
| Tirzepatide | 5 days | 36 hours | 3.6 weeks |
| Retatrutide | 6 days | not confirmed | 4.3 weeks |
| Cagrilintide | 7 days | not confirmed | 5 weeks |
| Dulaglutide | 5 days | 2 days | 3.6 weeks |
| Liraglutide | 13 hours | 10 hours | 2.7 days |
| Testosterone Cypionate | 8 days | not confirmed | 5.7 weeks |
| Testosterone Propionate | 20 hours | not confirmed | 4.2 days |
| hCG | 29 hours | 20 hours | 6 days |
| Anastrozole | 2 days | 2 hours | 10 days |
| Exemestane | 24 hours | 2 hours | 5 days |
| HGH | 3.5 hours | 3.5 hours | 18 hours |
| Tesamorelin | 8 minutes | 9 minutes | 39 minutes |
| Ipamorelin | 2 hours | not confirmed | 10 hours |
| CJC-1295 with DAC | 8 days | not confirmed | 5.7 weeks |
| Thymosin Alpha-1 | 2 hours | 2 hours | 10 hours |
Steady state is the point where each dose replaces what the body cleared since the last one, so the curve repeats the same peak and trough every interval. With dosing at a fixed amount and interval, each half-life closes half of the remaining gap: 50% after one half-life, 75% after two, 90% after about 3.3 and 97% after five. The dose changes how high steady state is, not how long it takes to get there.
Splitting the same weekly amount into more frequent doses keeps the average the same and narrows the swing. For testosterone cypionate at 100 mg per week, Dose Track's model gives a steady-state peak-to-trough ratio of about 1.33:1 twice weekly, 1.79:1 weekly and 3.23:1 every 2 weeks. A drug with a long half-life compared with its interval, like a weekly GLP-1, swings less to begin with.
It uses the same one-compartment model with first-order absorption as the Dose Track app:
k = ln 2 / half-life. The second rate is solved so the curve peaks at the time to peak: Tmax = ln(kₐ/kₑ) / (kₐ − kₑ). With no time to peak, one third of the half-life is used.A(t) = F·D · kₐ/(kₐ − kₑ) · (e−kₑt − e−kₐt), where F is bioavailability and D the dose.kₐ = ln 2 / half-life), and the amount still in the depot, F·D·e−kₐt, counts as in the system.1 / (1 − e−k·τ) for interval τ.t = −ln(1 − share) / ln 2 × half-life.The model uses a 70 kg reference body, as the app does when no weight is entered. Units are the estimated amount in the system, in the compound's dose unit.
These are modeled estimates from published half-lives, drawn with the same one-compartment model as the Dose Track app. Real levels vary from person to person, and only a lab test measures them. This is not medical advice and not a dosing recommendation; dosing decisions belong with you and your prescriber.
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