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
89.2% of the group given the combination plus olfactory training improved by 3 points or more. The 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.
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
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.