This is a topic that confuses a lot of people and even some vets. Melatonin can decrease the cortisol level. Usually this is not a significant decrease as was shown in the U of Wisconsin oral melatonin study. Lowering the cortisol level can lower the blood glucose level. However melatonin can also lower the insulin level which raises the glucose level, and melatonin can increase the production of glucose (gluconeogenesis) by the liver which also raises the glucose level. Thus the glucose level is usually not lowered by melatonin as was shown in the recent melatonin implant study at Colorado State. Therefore Lucia's low glucose level is more likely from an insulinoma (or other problem) and not from melatonin. Hope that clears up the confusion, Jerry Murray, DVM Brought here with author's permission to FHL Co-moderator, Sukie (not a vet) Recommended ferret health links: http://pets.groups.yahoo.com/group/ferrethealth/ http://ferrethealth.org/archive/ http://www.afip.org/ferrets/index.html http://www.miamiferret.org/fhc/ http://www.ferretcongress.org/ http://www.trifl.org/index.shtml http://homepage.mac.com/sukie/sukiesferretlinks.html P.S. For those who want to see info about the most recent article on melatonin and glucose levels (which found that over-all it decreased insulin enough that the result was higher glucose levels) although the work is not on ferrets: http://ferrethealth.org/archive/FHL7361 <http://www.sciencenews.org/index/generic/activity/view/id/39146/title/Lack_of_sleep_has_ge%3Dnetic_link_with_type_2_diabetes> and you can find earlier things in the FHL Archives by just searching message contents for things like melatonin and insulin or melatonin and glucose [Posted in FML 6239]