Safety and Efficacy of AlphaWave® l-Theanine Supplementation for 28 Days in Healthy Adults with Moderate Stress: A Randomized, Double-Blind, Placebo-Controlled Trial

Neurology and Therapy

May 2024

DOI: 10.1007/s40120-024-00624-7

Citations:5

Influential Citations:0

Interventional (Human) Studies

Enhanced Details

Methods

Randomized, double-blind, placebo-controlled, parallel-group study in healthy adults 18 to 65 years old with moderate stress (PSS 14 to 26). The active l-theanine group included 15 randomized participants, with a 1:1 allocation to l-theanine or placebo.

Intervention

AlphaWave® l-theanine was given orally at 400 mg/day as 200 mg per capsule, one capsule twice daily in the morning and evening for 28 days. The active regimen was compared with matching placebo in a randomized, double-blind trial.

Results

Overall, 28 days of AlphaWave® l-theanine appeared safe and showed modest benefits for perceived stress, sleep, and attention, but not salivary cortisol. Perceived Stress Scale scores fell by 17.98% at Day 28 in the l-theanine group (p = 0.04), while placebo also improved by 17.88% (p = 0.009), and there were no significant between-group differences in cortisol change. Actigraphy showed reduced light sleep after Day 14 and Day 28 versus placebo (p ≤ 0.040), and COMPASS Stroop correct reaction time improved by 21.79% and 21.33% at Day 14 and Day 28. The authors concluded the supplement was safe and well tolerated; adverse events were mild, with 8 events in 5 participants on l-theanine versus 1 event in 1 participant on placebo.

Limitations

The trial was small, with only 15 participants in the active arm, and lasted just 28 days. Participants were healthy adults with moderate stress, which limits generalizability, and placebo also showed meaningful improvement on perceived stress. The groups also differed at baseline for morning salivary cortisol, and there was no long-term follow-up or testing in people with more severe/pathological stress.

Abstract

Prolonged periods of stress may lead to negative health consequences. AlphaWave®l-Theanine was safe and efficacious during an acute stress challenge. However, double-blind, placebo-controlled clinical trials investigating the longer term effects of l-theanine supplementation on stress are warranted. Thirty healthy adults (18–65 years) with moderate stress were randomized to AlphaWave®l-Theanine (400 mg l-theanine/day) or placebo (n = 15/group) for 28 days. Stress was assessed by salivary cortisol, Perceived Stress Scale (PSS) and Depression, Anxiety and Stress Scale-21; sleep was assessed by the Healthy People Sleep Quality Index and actigraphy device; cognition was assessed by Computerized Mental Performance Assessment System; mood was assessed by Profile of Mood States. All outcomes were measured at baseline, Days 14 and 28. Safety included vital signs, clinical chemistry, haematology and adverse events (AEs). All AEs were resolved by the end of the study period or upon subsequent follow up, and out of range laboratory values and changes in vital signs were deemed not clinically relevant following AlphaWave®l-Theanine supplementation. Participants supplemented with AlphaWave®l-Theanine had decreases of 12.92% (p = 0.051) and 17.98% (p = 0.04) in PSS scores after 14 and 28 days, respectively, while those on placebo had respective decreases of 9.74% (p = 0.061) and 17.88% (p = 0.009). There were no significant differences between groups for change in salivary cortisol. The AlphaWave®l-Theanine group demonstrated decreased time asleep after 28 days and significantly reduced light sleep after 14 and 28 days compared to placebo (p ≤ 0.040). The AlphaWave®l-Theanine group significantly improved by 21.79% and 21.33% in Stroop test correct reaction time after 14 and 28 days, respectively, while those on placebo improved after 28 days only (p = 0.005). AlphaWave®l-Theanine supplementation for 28 days was safe and significantly decreased perceived stress significantly decreased perceived stress and light sleep, improved sleep quality and enhanced cognitive attention in the studied population. Larger, randomized controlled trials with longer duration of AlphaWave®l-Theanine supplementation are warranted to reduce inter-individual variability and the potential placebo effect. ClinicalTrials.gov identifier, NCT05808595. show less