After Fast Track consideration, the U.S. Food and Drug Administration approved the neffy epinephrine nasal spray for emergency treatment of allergic reactions and anaphylaxis, initially for those who weigh at least about 66 pounds).

Anaphylaxis can be a life-threatening allergic reaction and is considered a medical emergency. Epinephrine is the only treatment for anaphylaxis, it has been in common use for 100 years, but only as an injection. The approval of a nasal spray was based on four studies in 175 adults without anaphylaxis that measured the epinephrine concentrations in the blood following administration of neffy or approved epinephrine injection products. Results showed comparable epinephrine blood concentrations between neffy and approved epinephrine injection products and neffy also demonstrated similar increases in blood pressure and heart rate as epinephrine injection products, two critical effects of epinephrine in the treatment of anaphylaxis. A pediatric study (over 66 pounds) showed that epinephrine concentrations in children were similar to adults who received neffy.