A medical emergency with a complicated tool
Anaphylaxis (a severe, full-body allergic reaction) can kill within minutes if not treated with epinephrine. The drug works by reversing the most dangerous effects of the reaction — constricting blood vessels, relaxing airway muscles, and raising blood pressure.
The EpiPen has been the standard tool for decades. But real-world data shows many people do not use it when they should. The needle causes fear. The device is bulky. Some patients leave it at home. Others hesitate too long. Every second of delay matters when the airway is closing.
Needles create hesitation — hesitation costs time
Current options include intramuscular (IM) injectors like the EpiPen and Auvi-Q, manual syringes, and a newer nasal spray. Each works, but each has limitations in real-world use.
But here's the twist: researchers have spent years developing AQST-109 — a thin film that you place under your tongue, where it dissolves rapidly and releases epinephrine directly into the bloodstream through the mouth's lining.
Think of the underside of your tongue as a fast lane into the bloodstream. That tissue is rich with blood vessels and thin enough for certain molecules to pass through quickly without needing the digestive system.
AQST-109 is designed to take advantage of that pathway. The film dissolves in seconds, and the epinephrine absorbs directly through the sublingual mucosa (the tissue under the tongue) into the bloodstream. No injection. No device to assemble. No needle phobia to overcome.
Inside the Phase 3 trial
This was a two-part, open-label Phase 3 study — an advanced stage of clinical testing conducted in healthy adult volunteers. Participants received AQST-109 on some days and various injectable forms of epinephrine (manual IM injection, EpiPen, or Auvi-Q) on other days. Researchers tracked blood epinephrine levels, blood pressure, and heart rate for 360 minutes after each dose to compare how quickly and completely the drug was absorbed.
The headline finding: AQST-109 reached its peak blood concentration in a median of 12 minutes. That was faster than EpiPen (20 minutes), Auvi-Q (30 minutes), and manual injection (50 minutes).
Speed matters enormously in anaphylaxis. Earlier peak levels mean the drug starts reversing the reaction sooner. AQST-109 also produced more consistent results from person to person — a narrower range of outcomes — which means it is more predictable in an emergency than injectable options, where technique and injection site can vary.
The film also produced larger and faster increases in blood pressure and heart rate — the physical responses that counteract anaphylaxis — compared to all the injectable options.
AQST-109 is not yet FDA-approved and is not available to the public, but these Phase 3 results move it significantly closer to that goal.
One technical nuance worth noting
In terms of total drug exposure over the first 60 minutes, AQST-109 fell between manual IM injection and EpiPen on one end, and Auvi-Q on the other. It did not exceed all injectable options in every measure. But the faster peak and greater consistency may be the more clinically important advantages for emergency use, where reliable, rapid response matters most.
If you carry an epinephrine injector, do not stop using it or change your emergency plan based on this research. AQST-109 is still in clinical development and has not been approved by the FDA. But if you struggle with needle phobia, have difficulty using auto-injectors, or simply want to understand what options may become available, this is worth following. Talk to your allergist about the current landscape and whether your emergency action plan is as accessible as it should be.
This trial was conducted in healthy adult volunteers, not in people actively experiencing anaphylaxis. How the drug performs in a real emergency — with the body in a state of shock, blood pressure dropping, and circulation changing — is not yet known from clinical use. The study was also open-label, meaning participants knew what they were receiving, which could influence some measurements.
The developers of AQST-109 have submitted Phase 3 data as part of the regulatory review process. An FDA decision is anticipated, though no specific approval date has been publicly announced. If approved, AQST-109 would represent the first needle-free sublingual option for anaphylaxis in the United States — a potentially meaningful step toward making emergency allergy treatment more accessible to more people.
