Half-lives / Anastrozole
Anastrozole half-life
Anastrozole stays in your system about 9.6 days — five half-lives at a half-life of ≈ 46 h (46 h). The computed decay curve is below, with the primary source cited.
Also searched as: arimidex, adex.
Source: FDA label: Arimidex (anastrozole) prescribing information
Frequently asked
How long does Anastrozole stay in your system?
With a half-life of ≈ 46 h, roughly 97% of a single Anastrozole dose is cleared after five half-lives — about 9.6 days. Repeated dosing accumulates and takes correspondingly longer to clear.
What does a ≈ 46 h half-life mean in practice?
Every 46 h, the remaining amount halves: 100% → 50% → 25% → 12.5%, and so on. The curve above plots exactly this decay for a single dose.
Where does this Anastrozole half-life number come from?
FDA label: Arimidex (anastrozole) prescribing information. We cite a primary source for every half-life we publish and version every change.
Related: Anastrozole reconstitution calculator · Anastrozole dose charts
Related half-lives
Other TRT & hormonal support — how long each stays active:
Guides mentioning Anastrozole
See your own estimated levels
The Zyra Track app plots this curve from the doses you actually log — accumulation, overlaps, and all. Free during the founding period.
Zyra Track is a research and educational utility. Nothing on this page is medical advice, a dosing recommendation, or an endorsement of any compound. We never sell or source compounds and refuse sourcing questions. Consult a qualified clinician for decisions about your health.