Our Chumly really suffered form environmental allergies. I gave him the injections every week and it was the best thing we could have done for him. We had done the shampoos, sprays, antihistamines, Atopica and of course steroids. I would say he improved by a good 90 - 95%. He would still have flare-ups a couple of times a year during pollen season etc. and get the occasional yeast infection but we kept them under control with meds. It is not cheap but worth every penny for the difference it made in his quality of life. I would do it again in a second. I give credit to his Dermatologist Vet, she was great.