Hi Chris,  we used about a week’s worth of the yellow pills when the pharmacy didn’t have enough of the white ones.  It probably wasn’t long enough to affect his lab tests (he seems to be doing fine) but Marcus hated the way they tasted and would spit the pills out.  He has always taken his cortef and florinef without any complaints and I don’t think the regular pills taste that great, so the yellow ones must really taste bad.  For me, that is enough reason not to get them.  The pills he has now are white and are generic fludrocortisone also so I’m not sure if they potentially have the same problems Valerie was talking about.