Briskey · Nutrients 2023 · double-blind randomized placebo-controlled trial · n=108

The Effect of Levagen+ (Palmitoylethanolamide) Supplementation on Symptoms of Allergic Rhinitis-A Double-Blind Placebo-Controlled Trial.

Cited 3 times in the scientific literature.

Level 2 - randomized trial

Individual randomized controlled trial

PubMed 38068797 · doi:10.3390/nu15234940 · record verified 2026-08-29

What was done

A double-blind, randomized, placebo-controlled clinical trial evaluated 108 participants with seasonal allergic rhinitis who received either 350 mg of palmitoylethanolamide (PEA, Levagen+) or placebo daily for two weeks. Participants recorded symptom scores twice daily using the reflective total nasal symptom score (rTNSS). Blood samples were collected at baseline and week 2 to assess histamine and inflammatory markers (IL-4, IL-8, IL-10, TNF-α).

What was found

101 participants completed the trial with no baseline differences between groups. Across the full sample, no statistically significant difference in rTNSS allergy symptom scores was observed between groups over the 14 days. In a subgroup analysis of participants with baseline rTNSS over 4 (mild-to-moderate), Levagen+ significantly reduced scores compared to placebo (numerical values not reported in abstract). In blood pathology (n = 36 due to COVID-19 disruptions), Levagen+ showed significant decreases from baseline in histamine, IL-4, IL-8, IL-10, and TNF-α, whereas the placebo group showed a reduction in IL-4 only.

Why it matters

This study provides randomized human trial data on oral PEA for allergic rhinitis, demonstrating biological activity on inflammatory markers but failing to show overall clinical symptom benefit across the unstratified cohort.

Limits

The primary clinical symptom outcome (rTNSS) was not statistically significant across the whole study population. Reported symptom improvements were confined to a subgroup analysis without reported effect sizes, confidence intervals, or p-values in the abstract. Blood marker analyses were limited to only 36 participants due to COVID-19-related collection disruptions, and the follow-up period was short at two weeks.

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