I’ve heard that allergy drops are not approved by the FDA. Is that safe?

First, it’s important to understand that the antigens used in allergy drops are the same FDA-approved antigens used in allergy shots. They’re also prepared in the same way as allergy shots. The difference is the route of administration — a dispenser that delivers a drop of antigen under the tongue versus a syringe injecting antigen into tissue.

Antigens are labeled by the FDA for single use through injections and some for sublingual immunotherapy. A number of FDA-approved biologics are considered off label use when delivered via sublingual immunotherapy, which is both legal and highly common. Most physicians prescribe drugs in an off-label manner today, for example, the use of blood pressure medications for migraines, montelukasts for COPD, or arthritis drugs to treat shingles. Multiple antigen therapies for both injection and sublingual use are also an off-label use of  FDA-approved biologics.