Intramuscular (IM) epinephrine administered via manual injection, autoinjector, or as a nasal spray, are the current first-line treatments for anaphylaxis. AQST-109 is a needle- and device-free sublingual alternative epinephrine formulation in late-stage clinical development. To compare the pharmacokinetics (PK) and pharmacodynamics (PD) of single dose (SD) and repeat doses (RD) AQST-109 and IM epinephrine in healthy adults.