Cognitea
The short answer. There isn't much data on Cognitea yet — 3 mentions, 1 with a clear outcome — so treat these numbers as anecdotal. We found no human trials on PubMed.
From 3 mentions in total — the rest didn't say how it went and aren't counted.
What Cognitea does, according to users
Of the people who reported each effect, the share who said it got better.
What the research says
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
No randomized controlled trials in humans found on PubMed. The grade measures how much human research exists — read the conclusions below for what it found.
Dosage people report
As stated by users — not a recommendation. Follow the label or your doctor.
Reported side effects
How often each side effect came up across all reports.
What users say
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
“I did seem to feel more relaxed, and having taken powdered L-theanine for some time, it probably wasn't placebo.”
Other options for focus
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate