Categories are editorial navigation groups. They help readers compare curve shapes without implying a clinical recommendation, legal status, safety ranking, or shared risk profile.
What categories are for
HalfLifeDB categories help readers find related profiles and compare the representative half-life values used by the calculators. They are deliberately humble labels: useful for browsing, too blunt for decision making.
A category can contain substances with very different routes, metabolites, formulations, and study evidence. This directory keeps those small groups together instead of creating thin category pages. Open the individual profile when you need source links, checkpoint tables, and notes about uncertainty.
How to compare entries
Compare half-life values only after checking what the value represents. A parent compound, metabolite, terminal phase, effective half-life, or formulation-specific estimate can answer different questions. HalfLifeDB uses one representative value per profile so the educational curve stays readable.
The site does not use categories to suggest use, purchase, dosing, testing, or safety decisions. The educational focus is pharmacokinetic interpretation: what a simple curve shows, where it breaks down, and where source context should be checked.