Treatment of COVID-19 olfactory dysfunction with olfactory training, palmitoylethanolamide with luteolin, or combined therapy: a blinded controlled multicenter randomized trial
Randomised controlled trialHumansWith luteolin
This study tested palmitoylethanolamide together with luteolin. Its results cannot be assigned to palmitoylethanolamide alone. More combination studies.
- Design
- Randomised controlled trial
- Subjects
- 250 patients randomised into four groups. 202 completed.
- Dose used in the study
- 700 mg of palmitoylethanolamide with 70 mg of luteolin, once or twice a day, with or without olfactory training. The comparison group had olfactory training with a placebo.
- Duration
- 90 days
- What was measured
- Odour identification on the Sniffin' Sticks test. The main outcome was an improvement of 3 points or more.
What the authors reported
The trial found:
- 89.2% of the group given the combination plus olfactory training improved by 3 points or more.
- The comparison figures were 36.8% for training with placebo, 41.6% for the combination once a day alone, and 40% for the combination twice a day alone (p < 0.00001).
- No adverse events occurred.
- Patients on um-PEA-LUT alone (without olfactory training) had subclinical improvement (under 3 points) more often than those given training with placebo (p < 0.0001).
Limits of this study
The combination without olfactory training did about the same as training with placebo. The benefit appeared only when the two were used together. 19% of participants did not complete, and the authors note the risk of bias from that. Only odour identification was tested. The study had no funding source.
Source
PubMed 37380908 · doi:10.1007/s00405-023-08085-8
Entry checked against the article page at the publisher (Springer) on 2026-09-21. The dose shown is the dose the researchers used. It is not a recommendation. How to read this page.