Testosterone undecanoate half-life calculator
The half-life of Testosterone undecanoate is about 34 days (in castor oil). Enter your dose and schedule to see how your estimated level builds up, where it settles and how far it dips before each dose.
An estimate from the half-life alone. A blood test shows your actual level.
For planning only. Your prescriber sets your dose.
Questions about Testosterone undecanoate
What is the half-life of Testosterone undecanoate?
About about 34 days (in castor oil). After one half-life, half of a dose is still active; after two, a quarter.
How long until Testosterone undecanoate levels settle?
With regular doses, levels are about 90% settled after 3.3 half-lives (about 112.9 days) and close to fully settled after 5 (about 170 days). Changing the dose or schedule starts that settling again.
How long does Testosterone undecanoate stay active after the last dose?
It falls to about 10% after 3.3 half-lives (112.9 days) and about 3% after 5 (170 days).
See this for your own doses
Enhanced Training Studio draws this chart from the doses you actually log, with your blood tests on the same timeline. The protocol tracker is free, needs no account and keeps everything on your phone.
See the TRT tracker Weekly vs twice weekly