Tamoxifen half-life calculator
The half-life of Tamoxifen is 5–7 days. 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.
Tamoxifen in the compound library: what it is, its status, the research and known risks.
For planning only. Your prescriber sets your dose.
Questions about Tamoxifen
What is the half-life of Tamoxifen?
About 5–7 days. After one half-life, half of a dose is still active; after two, a quarter.
How long until Tamoxifen levels settle?
With regular doses, levels are about 90% settled after 3.3 half-lives (about 19.9 days) and close to fully settled after 5 (about 30 days). Changing the dose or schedule starts that settling again.
How long does Tamoxifen stay active after the last dose?
It falls to about 10% after 3.3 half-lives (19.9 days) and about 3% after 5 (30 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 weeklyOther compounds
More calculators: injection volume · reconstitution · any half-life. Terms explained in the glossary.