Radio Waves Could Help People Regain Their Sense of Smell

Our noses may soon get a painless boost. Scientists in South Korea report that radio waves can safely enhance the sense of smell by directly stimulating olfactory nerves in the brain.

The study, published in APL Bioengineering, found that a five-minute treatment improved odor sensitivity for more than a week in healthy adults. The method requires no drugs, no surgery, and no contact with the skin, raising hopes for new therapies for people with smell loss due to aging, injury, or COVID-19.

A new way to reach the brain’s smell center

The human sense of smell depends on olfactory neurons that send signals from the nasal cavity to the brain’s olfactory bulb. Traditional treatments for smell loss, such as olfactory training, rely on exposure to aromatic compounds. While somewhat effective, these approaches are indirect and can be uncomfortable or unreliable.

Radiofrequency (RF) waves, already used in technologies like MRI, have the ability to pass through bone and tissue. Researchers at Hanyang University and Kwangwoon University developed a patch antenna system that emits RF waves tuned to 2.45 GHz. Positioned about 10 centimeters from the forehead, the device stimulates olfactory nerves through the frontal bone without touching the skin.

Testing smell with Sniffin’ Sticks

The study enrolled 28 healthy young adults. Participants underwent standard odor threshold testing using “Sniffin’ Sticks,” pen-shaped odor dispensers containing diluted scents such as n-butanol, grape, banana, and apple. Researchers measured the minimum concentration detectable before and after RF stimulation, along with brain activity in the olfactory bulb using electrobulbogram recordings.

The results were striking. The average odor threshold score jumped from 9.73 to 15.88 out of 16 after just one five-minute session at 10–20 watts. This improvement indicated near-perfect sensitivity to faint odors. The effect lasted for up to seven days.

Safe, painless, and chemical-free

The team verified safety using 3D modeling and skin temperature measurements. Forehead temperatures remained stable, and no overheating or discomfort was reported. Unlike electrical stimulation methods, which often struggle to penetrate the skull, RF waves reached the olfactory nerves effectively.

“The method is completely noninvasive — no surgery or chemicals needed — and safe, as it does not overheat the skin or cause discomfort,” said coauthor Yongwoo Jang of Hanyang University (APL Bioengineering).

Potential applications beyond smell loss

The immediate study tested people with normal olfactory function, showing that RF stimulation can temporarily heighten sensitivity. This suggests applications for professionals who depend on fine distinctions of smell, such as perfumers, sommeliers, or coffee tasters. More importantly, researchers plan next to study individuals with anosmia (complete loss of smell) or hyposmia (reduced smell), conditions that affect millions worldwide.

Key findings

• Five minutes of RF stimulation improved smell sensitivity scores by more than 60 percent.
• The effect lasted up to one week after a single session.
• No overheating or discomfort was observed.
• Enhanced responses were seen for both synthetic odorants and natural fruit scents.

What comes next

Future research will explore repeated treatments, effects in older adults, and therapeutic potential for neurodegenerative diseases such as Parkinson’s and Alzheimer’s, where smell loss is an early symptom. Because RF stimulation can target nerves without chemicals, it may also avoid allergic reactions and variability seen in aroma-based therapy.

By laying the groundwork for a new class of neurostimulation treatments, this study opens the door to restoring and even enhancing a sense that is often overlooked but vital for safety, nutrition, and emotional well-being.

Journal: APL Bioengineering
DOI: 10.1063/5.0275613