Platelet-rich plasma (PRP) injection into the olfactory vault for post-viral, post-traumatic or idiopathic olfactory loss

Loss of smell (anosmia) or reduced smell (hyposmia) profoundly affects quality of life: enjoyment of food disappears, warning signals (smoke, gas, spoiled food) are missed, and many patients experience isolation or even depression. Although a proportion of post-COVID smell disorders recover spontaneously, a large number of patients – together with those affected by head trauma, previous viral infections or idiopathic causes – are left with persistent, often permanent dysfunction.

Evidence from level 1 and 2 studies (2021–2025) has shown that autologous platelet-rich plasma (PRP) injected directly into the olfactory cleft and onto the olfactory neuroepithelium can significantly improve smell function in patients whose spontaneous recovery has plateaued after 6–12 months. PRP is rich in growth factors (PDGF, TGF-β, VEGF, IGF-1, etc.) and anti-inflammatory cytokines that promote regeneration of olfactory receptor neurons and supporting cells, and in some cases even partial regrowth of olfactory nerve fibres.

The procedure is performed entirely by our otorhinolaryngologist–head and neck surgeon under local anaesthesia in an outpatient setting and lasts 20–30 minutes. A small volume of the patient’s own blood (20–40 ml) is drawn, centrifuged in our certified laboratory to concentrate the platelets, and the resulting PRP is precisely injected bilaterally into the olfactory vault under high-definition endoscopic guidance. The standard protocol consists of 3 injections spaced 4–6 weeks apart.

Clinical results (international multicentre data 2023–2025)

• 65–75 % of patients show objective improvement on validated smell tests (Sniffin’ Sticks, UPSIT)
• 40–55 % regain functionally useful smell (normosmia or mild hyposmia)
• Best responses in post-viral (including post-COVID-19) and post-traumatic cases
• Earlier treatment (within 1–3 years of onset) gives higher success rates
• No serious complications reported worldwide to date

Our philosophy

Patients with long-standing smell loss deserve access to the most promising evidence-based regenerative treatments available today, delivered with complete transparency about realistic expectations. Before starting, every patient undergoes thorough evaluation (endoscopy of the olfactory cleft, validated psychophysical smell testing, and MRI when indicated) to confirm regenerative potential and exclude alternative treatable causes.

Who is this treatment for?

• Persistent olfactory loss >12 months after COVID-19 or other viral infections.
• Post-traumatic anosmia/hyposmia with patent olfactory cleft.
• Idiopathic olfactory dysfunction with remaining neuroepithelium.
• Patients who have plateaued with olfactory training alone.
• Motivated individuals comfortable with a short series of nasal injections under local anaesthesia.

Advantages of Clinica Omega Zeta Andorra

• Performed personally by an ENT surgeon with fellowship-level expertise in olfactory disorders and advanced endoscopic techniques.
• Latest-generation high-definition endoscopy suite in a calm, private Pyrenees setting.
• Possibility of same-day combination with other nasal treatments if required.
• Multilingual team (English, Spanish, French, Catalan, Portuguese).
• Rapid access – consultation and first injection usually within one week.
• Complete discretion and personalised care in the tranquil microstate of Andorra.