Ingredient Spotlight — L-Theanine (Suntheanine®) · PM Formula
Quiet the Mind
The thing standing between you and good sleep usually isn't your body — it's a mind that won't stop narrating. A four-week human trial measured what L-theanine does to sleep quality and the sense of being wound-too-tight.
You know the feeling of lying down exhausted and finding your head still going — replaying the day, pre-playing tomorrow. L-theanine, the amino acid that gives green tea its calm-without-drowsy character, has long been associated with a settled, alert-but-relaxed state. This study asked whether four weeks of it meaningfully changes how you sleep and how wound-up you feel.
The trial
In a randomized, placebo-controlled, double-blind crossover study, 30 healthy adults took L-theanine (Suntheanine®, 200 mg/day) or placebo for four weeks each. Sleep quality was measured with the validated Pittsburgh Sleep Quality Index (PSQI), alongside stress-related and cognitive measures.
What they found
- Better sleep quality. PSQI sleep scores improved significantly after L-theanine versus baseline.
- The right parts of sleep. Compared with placebo, L-theanine improved the PSQI subscales for sleep latency, sleep disturbance, and use of sleep medication — the specific problems that keep a busy mind up.
- Sharper by day, too. Verbal fluency and executive-function scores improved after L-theanine — the daytime dividend of better-quality nights.
The authors concluded L-theanine "has the potential to promote mental health in the general population with stress-related ailments and cognitive impairments" — in a healthy population, at a real-world dose, with no adverse events.
Not sedation. A quieter mind, so sleep can do what it already knows how to do.
Why it's in the PM formula
Suntheanine® is the L-theanine our nighttime formula is built on — the same branded material and 200 mg dose studied here. It quiets the mental chatter that delays sleep, and it pairs with PharmaGABA® to lower the day's stress load: two calming actives working the same wind-down, with human data behind each.
Reference: Hidese S, Ogawa S, Ota M, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019;11(10):2362. doi:10.3390/nu11102362.
Read it: https://pubmed.ncbi.nlm.nih.gov/31623400/
Suntheanine 200 mg is in NeuraLegend AM and in NeuraLegend PM. The reports for the lot now shipping are on the AM 3rd party testing reports and the PM 3rd party testing reports. It is also in the Full System.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.