How fast do injected levels fall?
About half every eight days. The Depo-Testosterone label gives testosterone cypionate injected into muscle a half-life of approximately eight days. A 2026 review of testosterone pharmacokinetics describes cypionate and enanthate as behaving similarly, with half-lives of roughly eight days and somewhat more variability for enanthate.
Halving every eight days gives a simple timeline for the contribution of your final shot.
| Time since the last injection | Share of that injection still contributing |
|---|---|
| About 8 days | About half |
| About 16 days | About a quarter |
| About 24 days | About an eighth |
| About 32 days | Around 6% |
| About 40 days | Around 3% |
By five to six weeks, the injected testosterone has largely cleared. If you were on a weekly schedule, earlier doses are further along the same curve, so the overall picture is similar.
The same kinetics shape every dosing cycle while you are on treatment. The review notes that cypionate typically peaks between days 2 and 5 after a shot and falls to its low point by days 13 to 14 on a two-week schedule. After the final dose there is simply no next peak, so the decline continues until the injected supply is gone.
When does your own baseline come back?
Later than the injected testosterone leaves. While you are on TRT, the outside hormone tells your pituitary to stop sending LH, the signal your testes need to make testosterone. Once the injected supply runs out, that signal has to restart before your own production can recover, and how long that takes differs between men.
That gap is why some men feel worse for a while after stopping, and why labs after a stop are timed with care. Our page on blood work after coming off TRT explains which tests are drawn and when, and the answer on what happens when you stop TRT covers the symptoms to expect.
How is sport drug testing different?
It asks a different question: not whether your level is normal, but whether testosterone came from outside your body. Testosterone is on the World Anti-Doping Agency’s Prohibited List, and MedlinePlus notes that athletes are tested for anabolic steroids and that how long any drug stays detectable depends on the drug, the dose, how long it was used and how the body handles it.
Anti-doping labs use tools that do not depend on a high blood level. A 2025 study in Drug Testing and Analysis describes the urinary testosterone to epitestosterone ratio, isotope ratio testing that can confirm testosterone came from outside the body, and newer dried blood spot methods that detect the testosterone ester itself. In that study, blood spot testing detected testosterone use in every participant, including men whose naturally low urine ratio let them slip past the standard urine screen.
So a level that has returned to the normal range does not mean a test would come back clean. Detection depends on the method, not on when you start to feel like yourself again.
Related question: does TRT show up on an ordinary drug test?
Workplace panels and sport testing are different tools. Our answer on whether TRT shows on a drug test covers employment screening, and the answer on TRT for competitive athletes covers sanctioned sport.
How Ultimate Male plans a stop or a pause
If you are thinking about stopping, talk with your provider before skipping doses. Together you can decide whether to stop outright, taper or pause, and when to draw labs so the results mean something.
If you compete in a tested sport, even at the masters level, raise it at your first consultation, before treatment starts, so your provider can explain how testosterone therapy and your sport’s rules interact. The free 10-minute call is an easy place to begin.
