Yep, one of mine gets immunotherapy for his allergies. But I decided to do the drops twice a day instead of the weekly shot. I just couldn't bring myself to do anything to him with a needle.
He's been on it for about 9 months and we're just now starting to see improvement. Yeah, it took that long. But his dermatologist said it could take up to a year. He still itches now and then, but nothing compared to what he used to be like and it's allergy season now. So I'm extremely happy with the changes.
Thing is, it's a life long commitment. If you decide to do the allergy shots/oral drops, you can never stop.. because if you do, the allergies come back.