Hormone Half-Life Calculator

Because ester pharmacokinetics and serum hormone levels are related but different things. The ester is the depot form that releases hormone over time. Your measured total testosterone or estradiol also reflects binding proteins, aromatization, and clearance that vary between individuals. This tool gives you the ester curve; your lab panel gives the actual serum level.

Select Custom and enter the half-life in days from your medication's prescribing information or package insert. Published pharmacokinetic studies for your specific ester and formulation are the most accurate source. Your prescriber or a pharmacist can also provide this information.

You can use it to visualize how quickly your ester depletes between doses, which helps illustrate why certain injection frequencies are recommended. However, adjusting your injection schedule should always be done in consultation with your prescribing physician, who will use blood levels and clinical assessment to guide decisions.

It shows what fraction of the injected ester has not yet been cleaved and released. It is a relative measure within a single injection cycle. It does not directly correspond to your serum hormone level as a percentage of any reference range, because the conversion depends on individual pharmacokinetics and binding protein levels.