I've been using it for about a week now for my two big leos. They are around 55 grams each, and have not been eating, but also not losing weight. So I tried appetite plus to try to get them to eat. After a week, I have not seen an improvement in eating, but they seem to be more active and aware of what is going on around them. Before giving them it, they just laid on the heating pad all day, now they walk around and explore their cage much more frequently, as far as feeding, I have not noticed an improvement though.