Persistent COVID-19 parosmia and olfactory loss post olfactory training: randomized clinical trial comparing central and peripheral-acting therapeutics
Randomised controlled trialHumansWith luteolin; alpha-lipoic acid in two arms
This study tested palmitoylethanolamide together with luteolin; alpha-lipoic acid in two arms. Its results cannot be assigned to palmitoylethanolamide alone. More combination studies.
- Design
- Randomised controlled trial
- Subjects
- 120 adults (18 to 60) with persistent smell loss and parosmia after COVID-19 that had not resolved with earlier olfactory training; 89 analysed after 31 dropped out (17 PEA-luteolin, 21 alpha-lipoic acid, 28 both, 23 olfactory training alone)
- Dose used in the study
- One sachet daily of ultramicronised PEA 700 mg plus luteolin 70 mg (Glialia, Epitech); alpha-lipoic acid 800 mg daily; or both; all groups did daily olfactory training
- Duration
- 6 months
- What was measured
- Sniffin' Sticks TDI score and a parosmia questionnaire at baseline and 6 months; assessors blinded to treatment
What the authors reported
TDI rose from 21.8 to 29.7 in the PEA-luteolin group and from 19.6 to 27.5 in the combination group (both p < 0.01). The alpha-lipoic acid group and the training-only group did not change significantly. Parosmia resolved in 96 percent of the combination group, 65 percent of controls, 53 percent of the PEA-luteolin group and 29 percent of the alpha-lipoic acid group. All regimens were well tolerated.
Limits of this study
Almost 30 percent dropped out, unevenly across groups (13 of 30 in the PEA-luteolin arm). Small groups after attrition. No placebo; the control arm had training only, and patients were not blinded. Baseline smell scores and ages differed between groups. Single centre. The parosmia result does not follow the TDI result: the training-only group had a higher parosmia resolution rate than the PEA-luteolin group. Authors report no conflicts and no specific funding; the product is a commercial Epitech sachet.
Source
doi:10.1007/s00405-024-08548-6
Entry checked against the full text (open access PDF), supplied by Devlin on 2026-09-21. The dose shown is the dose the researchers used. It is not a recommendation. How to read this page.