Evidence supporting the use of: Theanine
For the health condition: Stress
Synopsis
Source of validity: Scientific
Rating (out of 5): 3
L-Theanine is an amino acid commonly found in tea leaves, particularly green tea. Its use for stress reduction is supported by a moderate level of scientific evidence. Several randomized, double-blind, placebo-controlled trials have reported that L-theanine supplementation can have calming effects and reduce subjective stress levels in healthy adults. The proposed mechanism involves its influence on brain neurotransmitters, including increased alpha brain wave activity, which is associated with a relaxed but alert mental state. Some studies also suggest theanine may modulate levels of cortisol, a hormone linked to stress responses.
A 2016 systematic review in Phytotherapy Research concluded that L-theanine supplementation appears to be safe and may reduce stress and anxiety in people exposed to stressful conditions. Another meta-analysis published in 2019 in the journal Nutrients indicated that L-theanine has a positive effect on stress and anxiety, though the overall number of high-quality trials remains limited.
While the evidence is promising, it is not yet robust enough for universal clinical recommendation. Most studies have small sample sizes and short durations. Overall, scientific support for L-theanine’s use in stress management is moderate, and more large-scale, long-term studies are warranted to confirm its efficacy.
Other ingredients used for Stress
5-Hydroxytryptophan (5-HTP)7-Keto-DHEA
acetyl l-carnitine
alpha-pinene
arjun tree
ashwagandha
asparagus
astragalus
waterhyssop
benegut perilla (proprietary)
bergamot
bifidobacterium bifidum
bifidobacterium lactis
bifidobacterium longum
sesame
black tea
bonito peptide
bupleurum falcatum
California poppy
caterpillar mushroom
chaga mushroom
chamomile
cordyceps
curcumin
damiana
DHA (docosahexaeonic acid)
dong quai root
eleuthero
EPA (eicosapentaenoic acid)
epigallocatechin gallate (EGCG)
fish protein
GABA (gamma aminobutyric acid)
gardenia
gotu kola
green tea
guayusa
heartwood
hibiscus
hops
jujube
kava root
kudzu
l-ornithine
l-taurine
l-theanine
l-tryptophan
l-tyrosine
lactium casein decapeptide
lactobacillus brevis
lactobacillus casei
lactobacillus helveticus
lactiplantibacillus plantarum
lavender
lentinula edodes mycelia
lion's mane
liquid liver fractions
maca
magnesium
magnolia
matcha
melatonin
mint
motherwort
muira puama
Acetyl-L-Tyrosine
oat
passionflower
peppermint oil
perilla
phosphatidylserine
phospholipids
pine bark
polygala root
pregnenolone
pyrroloquinoline disodium salt
quail egg
relora® (proprietary)
rhodiola
rose oil
saffron
sceletium
black ginger
skullcap
spearmint leaf
spinach
valerian root
velvet bean
vitamin B12
vitamin B6
mulberry
whole adrenal glandular
zinc
sarsaparilla
suma
jiaogulan
catnip
cardamom
anise
fumaria parviflora
bee pollen
lingzhi
kanna
silk tree
oriental arborvitae
anemarrhena asphodeloides
St. John's Wort
yerba mate
noni
wood betony
biota seed
goji berry
cocoa
AMP-activated protein kinase (AMPK)
ashitaba
7,8-Dihydroxyflavone
Aralia
Arjuna
akebia
Antler
Agastache
Agrimony
Apigenin
Antrodia camphorata
Arginine aspartate
Albizia
Anserina
Agmatine
Agarwood
Alpha lactalbumin
Algal protein
Betony
Baikal Skullcap
Black spruce
Baccosides
Bacopin
Baicalein
Basidiomycota
Banyan
Brahmi
Bacopa
Buddha's Hand
Borage
banana
Bifidobacteria
Bupleurum
bacoside
Baicalin
Bird's nest
Centella triterpenes
Common Monkey Flower
Clary sage
Chinese Mountain Ant
Codonopsis
Coriander
Clerodendrum phlomidis
Chinese Fleeceflower
Chuchuhuasi
Cymbopogon Martini
Calea zacatechichi
Centella asiatica
Coca
Chocolate
Capitate Valerian
Corktree
Catuaba
C-Phycocyanin
cypress
Cowslip
Calamus
Cherimoya
Convolvulus prostratus
Corydalis
Convolvulus Pluricaulis
Celastrus
Canscora
Dismutase
Dodeca-2E, 4E-Dienoic Acid Isobutylamide
Dibenzo-alpha pyrones
Devil's Club
Date
Dodeca-2E, 4E, 8Z, 10Z/Etetraenoic Acid Isobutylamide
Eplotab
Erythrina
Emblicanin
Eurycoma Longifolia
Fo-Ti
Fragrant Rosewood
Ficus religiosa
Fish
Frankincense
Flavones
Goldthread
Gelsemium
Ginsenosides
Griffonia simplicifolia
Galactooligosaccharides
Glycine
Gastrodin
jasmine
Lotus
Mistletoe
Mimosa
Orchid
Poppy
Pistachio
Rose
Spikenard
yohimbine
Other health conditions supported by Theanine
Addictions (coffee, caffeine)Anxiety
Anxiety Disorders
Depression
Hypertension
Memory and Brain Function
Mood Swings
Stress
Worry
