Carol, if I am not mistaken, one study that I read re. potency being higher referred specifically to Prednisolone but didn’t seem to mention Prednisone....so I don’t know if that was assumed and I’m too dumb to see it ;-) (Sept 2003, The Journal of Pediatrics: Prednisolone in the treatment of adrenal insufficiency ; a re-evaluation of relative potency). If you know of other studies I’d be pleased to read them.

Although Prednisone is similar to Prednisolone, as I understand it Prednisolone already exists in a metabolically active form whereas Prednisone must be converted in the liver to it’s active metabolite - Prednisolone. Having said that although this difference may affect some things such as absorption time I don’t see how it would affect actual potency - so as you say Prednisone may also be more potent than has previously been calculated.

I wish some of these things could be clarified more but I suppose that is part of the reason for doing the study which Jenny mentioned.