PRP Shows Promise for Post-Traumatic Anosmia

From the AAO-HNSF

A new treatment using platelet-rich plasma (PRP) injections has shown promising results in helping people recover their sense of smell after head injuries, according to a preliminary study published in the November 2025 issue of Otolaryngology–Head and Neck Surgery. 

PRP therapy involves using a patient's own blood plasma, which is rich in growth factors that promote healing and tissue regeneration. The treatment is injected into the olfactory cleft—the area in the upper nose responsible for detecting smells.

The study was led by Jerome R. Lechien, MD, PhD, from the University of Mons in Belgium. It examined 33 patients who had lost their sense of smell following head trauma. After receiving PRP injections into the nasal area, two-thirds of patients reported improvements in their ability to smell, with significant objective improvements measured at three months.

Jerome R. Lechien, MD, PhD"This groundbreaking study is the first worldwide to demonstrate that platelet-rich plasma injection into the olfactory clefts can significantly improve smell recovery in post-traumatic patients—sometimes several years after the trauma," said Dr. Lechien. "To date, there is no effective treatment for smell loss following head trauma. This novel treatment offers new hope for head trauma patients suffering from persistent smell loss, a condition that profoundly impacts quality of life and safety." 

The study found that 67% of patients who received PRP treatment reported subjective improvement after a single injection. Psychophysical testing revealed significant increases in smell scores, achieving clinically meaningful improvements that were superior to olfactory training alone. On average, patients detected their first recovered odors within 5.4 weeks after treatment.

The study included patients who had been experiencing smell loss for an average of nearly five years (55 months), suggesting that even long-standing cases may benefit from treatment.

Clinical Implications

Studies indicate that 5%-30% of patients who experience head trauma suffer from smell loss.

Between 17% and 27% of people who lose their sense of smell after head trauma may experience some natural recovery, but many face permanent loss with limited treatment options—until now. Only approximately 10% of patients recover some olfactory function through smell training protocols alone.

While these results are preliminary and based on a small group of patients, they represent the first investigation of PRP effectiveness specifically for trauma-related smell loss. Dr. Lechien notes that larger randomized controlled trials are needed to confirm these findings. 

The full study is available in Otolaryngology–Head and Neck Surgery (November 2025, Volume173, Issue5). DOI: 10.1002/ohn.1358