Unless something has changed, the Melatonin implants are actually enclosed in a plastic case that is left behind once the medicine is actually dissolved/used. This *does* result in "husks" being left behind, and usually if it's a problem, you can have the vet remove them very quickly. In older ferrets they can end up irritating the skin because of the thinner skin up there. I injected 10 younger ferrets early on in life when I had just personal ferrets - on the females, I can see the implant husk there, I planned on continuing it to see if it would prevent adrenal disease but when I learned the husks remained, I decided not to, and also I got into rescue and doing it for non-adrenal ferrets was a cost I did not want to try. As far as reactions - I never had a ferret have a reaction to a melatonin implant. I did have a ferret have a localized skin reaction to a lupron depot given in the scruff area. I also gave a female ferret an IM lupron depot in the thigh, and had no reaction. The reaction was just a hard lump with orange/red skin. I have done many melatonin implants since then on rescues, other people's ferrets, and never had an issue. If she can't handle melatonin, I wonder if lupron would be okay - it is not an actual implant, though. There is also Deslorelin, but I am not certain if that is an implant or depot - I believe it's an implant? L [Posted in FML 6934]