Glossary
Duration of action
Also written duration, how long it lasts
How long an effect lasts. This is not the same as half-life and often much longer.
Half-life describes clearance from the blood. Duration describes how long something keeps doing what it does. The two come apart whenever the effect outlasts the molecule.
TB-500 is the clearest example here: a short half-life alongside a dosing schedule of once a week, on the reasoning that what it sets in motion continues after it is gone. Whether that is true is a separate question; the point is that inferring a schedule from a half-life alone gets it wrong.
Where a source gives a dosing frequency that does not follow from the half-life, our profiles show both and say which is which rather than reconciling them.