Help Guide › Owner
Supplies split three ways, because they're bought from three different places:
Anything already filed under the old single Supplies heading stays where it is until you move it.
A product named after a compound in the library takes that compound's category automatically, whether or not anything links the two — so typing "Retatrutide 10mg" files it under the same heading as the library entry. You can always set a category by hand and it wins; the picker shows what the app would choose so you can see the guess before accepting it.