As with any compounded, complex treatment, there is an extremely large variation in the quality of available treatments and treatment programs. Allergies are extremely prevalent, and patients, physicians, and companies are all searching for ways to treat these allergies. Given the overall safety of sublingual immunotherapy, several companies have started to provide compounding services for some type of “allergy drops” based on a variety of factors: some make a generic formulation that has no relationship to your specific allergies at all and that you can buy over the counter or on amazon.com, some use a protocol to formulate drops for you based on blood test results alone, and others may get some input from a physician who did some type of testing on you. These companies market either directly to consumers or they market to doctors as another treatment tool for their allergic patients. Some of these companies may use FDA approved antigens while others may not. Any dose-related information is usually hard to find and there is often concern about doses being too low, leading to less effective results.
Just as with any type of medical service or treatment, it is best to both do a little bit of your own research and also talk with a trusted physician who has a particular knowledge on the topic. Ask for some details about the sublingual immunotherapy treatment you are considering, who is managing it, where the antigens come from, how the dosing is decided, etc in order to make sure you are comfortable pursuing it from that particular place and to make sure you are getting the type and quality of treatment that you desire.