Trial reportEuropean archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery2023
Treatment of COVID-19 olfactory dysfunction with olfactory training, palmitoylethanolamide with luteolin, or combined therapy: a blinded controlled multicenter randomized trial.
Trial report in European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07631455 (Effects of Ultramicronized Palmitoylethanolamide on Smell, Taste, and Sensory Sensitivity in Children With Autism Spectrum Disorder.), which is not on this map. Cited by 18 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Effects of Ultramicronized Palmitoylethanolamide on Smell, Taste, and Sensory Sensitivity in Children With Autism Spectrum Disorder.
Who cites it
18 citing papers in PubMed, 2 syntheses or guidelines pooled it, 20 citations in OpenAlex.
- Therapeutic effect of anti-neuroinflammatory supplement combined with olfactory training on post-covid olfactory dysfunction: a systematic review and meta-analysis.European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · 2026Pooled it
- Treatment of COVID-19 Associated Olfactory Dysfunction: A Systematic Review.Current allergy and asthma reports · 2024Pooled it
- Corrigendum to 'Effects of therapeutic interventions on long COVID: a meta-analysis of randomized controlled trials'.EClinicalMedicine · 2026Article
- Investigating Properties of Palmitoylethanolamide in Physiology and Disease: Far Beyond an Anti-Inflammatory Shield.Diseases (Basel, Switzerland) · 2026Review
- A Prefrontal Neuromodulation Route for Post-Traumatic Olfactory Dysfunction: A Perspective Supported by Recovery During Left-DLPFC rTMS.Brain sciences · 2026Article
- Article
- Olfactory Training for Post-COVID-19 Olfactory Dysfunction: A Meta-Analysis of Efficacy and Combination Therapies.Journal of clinical medicine · 2025Review
- Effects of therapeutic interventions on long COVID: a meta-analysis of randomized controlled trials.EClinicalMedicine · 2025Article
- Article
- SARS-CoV-2-induced sensory perturbations: A narrative review of clinical phenotypes, molecular pathologies, and possible interventions.Brain, behavior, & immunity - health · 2025Review
- Palmitoylethanolamide supplementation for human health: A state-of-the-art systematic review of Randomized Controlled Trials in patient populations.Brain, behavior, & immunity - health · 2025Review
- Inflammatory pathways in patients with post-acute sequelae of COVID-19: The role of the clinical immunologist.Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology · 2024Review
- Palmitoylethanolamide, an endogenous fatty acid amide, and its pleiotropic health benefits: A narrative review.Journal of biomedical research · 2024Article
- Polyunsaturated Fatty Acids as Potential Treatments for COVID-19-Induced Anosmia.Biomedicines · 2024Review
- Assessment of Supplementation with Different Biomolecules in the Prevention and Treatment of COVID-19.Nutrients · 2024Review
- COVID-19-Associated Sepsis: Potential Role of Phytochemicals as Functional Foods and Nutraceuticals.International journal of molecular sciences · 2024Review
- Possible Role of Cannabis in the Management of Neuroinflammation in Patients with Post-COVID Condition.International journal of molecular sciences · 2024Review
- Comparative analysis of COVID-19 responses in Japan and Africa: diet, phytochemicals, vitamin D, and gut microbiota in reducing mortality-A systematic review and meta-analysis.Frontiers in nutrition · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
14 authors at 5 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeFew evidence-based therapies are available for chronic olfactory dysfunction after COVID-19. This study investigated the relative efficacy of olfactory training alone, co-ultramicronized palmitoylethanolamide with luteolin (um-PEA-LUT, an anti-neuroinflammatory supplement) alone, or combined therapy for treating chronic olfactory dysfunction from COVID-19.
methodsThis double-blinded controlled, placebo-controlled multicenter randomized clinical trial was conducted in 202 patients with persistent COVID-19 olfactory dysfunction of > 6 month duration. After a screening nasal endoscopy, patients were randomized to: (1) olfactory training and placebo; (2) once daily um-PEA-LUT alone; (3) twice daily um-PEA-LUT alone; or (4) combination of once daily um-PEA-LUT with olfactory training. Olfactory testing (Sniffin' Sticks odor identification test) was performed at baseline and at 1, 2, and 3 months. The primary outcome was recovery of over three points on olfactory testing, with outcomes compared at T
resultsAll patients completed the study, and there were no adverse events. At 90 days, odor identification scores improved by > 3 points in 89.2% of patients receiving combined therapy vs. 36.8% receiving olfactory training with placebo, 40% receiving twice daily um-PEA-LUT alone, and 41.6% receiving once daily um-PEA-LUT alone (p < 0.00001). Patients receiving treatment with um-PEA-LUT alone demonstrated subclinical improvement (< 3 point odor identification improvement) more often than patients receiving olfactory training with placebo (p < 0.0001.)
conclusionsOlfactory training plus once daily um-PEA-LUT resulted in greater olfactory recovery than either therapy alone in patients with long-term olfactory function due to COVID-19.
trial registration20112020PGFN on clinicaltrials.gov. LEVEL OF EVIDENCE: 1b (Individual Randomized Clinical Trial).
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.