Evidence supporting the use of: L-tryptophan
For the health condition: Insomnia

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Synopsis

Source of validity: Scientific
Rating (out of 5): 3

L-tryptophan is an amino acid that serves as a precursor to serotonin, a neurotransmitter involved in mood regulation and sleep-wake cycles. The scientific rationale for using L-tryptophan to support or treat insomnia is based on its role in increasing brain serotonin levels, which can then be converted into melatonin, a hormone that regulates sleep. Several clinical studies, particularly from the 1970s and 1980s, showed that L-tryptophan supplementation (usually 1-5 grams at bedtime) could decrease the time it takes to fall asleep and improve sleep quality in some individuals, especially those with mild insomnia or sleep disturbances. However, more recent meta-analyses and systematic reviews suggest that while there is some evidence for efficacy, the overall effect size is modest, and results are inconsistent across studies.

L-tryptophan use declined sharply after reports in the late 1980s of eosinophilia-myalgia syndrome (EMS) linked to contaminated supplements, though the risk from pure L-tryptophan appears low. Currently, L-tryptophan is available as a dietary supplement, and its use for insomnia remains supported by some evidence but is not as robust or consistent as prescription sleep aids or other interventions. Overall, while scientific evidence exists to justify its use for sleep support, it is moderate in quality and strength.

More about l-tryptophan
More about Insomnia

Other ingredients used for Insomnia

5-Hydroxytryptophan (5-HTP)
amino acids
ashwagandha
waterhyssop
benegut perilla (proprietary)
black cumin
Indian frankincense
rice
calcium
California poppy
cassia bark
chamomile
cherry
Chinese salvia root
cinnamon
Coptis chinensis
fennel
GABA (gamma aminobutyric acid)
gooseberry
gotu kola
greek mountain tea
heartwood
hops
jujube
kava root
kudzu
l-tryptophan
lactium casein decapeptide
lavender
maca
magnesium
magnolia
marine lipid
melatonin
moringa
motherwort
ophiopogon root
orange
passionflower
perilla
phytocannabinoids
pollen
polygala root
quail egg
reishi mushroom
rose oil
saffron
sage
scrophularia root
skullcap
valerian root
vitamin B6
zinc
catnip
tangerine
anise
blackboard tree
lingzhi
lingusticum wallichii
morus
silk tree
chrysanthemum
amber
ganoderma
lotus seed
anemarrhena asphodeloides
purslane
aster root
peach
wood betony
goji berry
soursop
Aralia
Agastache
Alpha-terpineol
Angelica
Apigenin
Anamu
Albizia
Agarwood
Anemone
Alpha lactalbumin
Agrimonia pilosa
Arani
Atractylone
Betony
Black Seed
Baikal Skullcap
Blackthorn
Balsam
Bayleaf
Big Quaking Grass
Banyan
Brahmi
Borassus Palm
Borassus aethiopum
Bupleurum
Centella triterpenes
Chinese Silkvine
Clary sage
Clerodendrum trichotomum
Cactus
Cyathula
Citron
Carry Me Seed
Cannabinol
Cymbopogon Martini
Calea zacatechichi
Centella asiatica
Capitate Valerian
Corktree
Cowslip
Cannabidiol
Calamus
Cherimoya
Corydalis
Carthamus
Clerodendrum indicum
Dragonhead
David's Milkberry
Doxylamine succinate
European Elder
Erodium cicutarium
Elk antler
Elephant's Head
Embelia
Glycine
jasmine
Lotus
Lily
Little ironweed
Mallow
Milk Protein
Mimosa
Orchid
Poppy
Rose
Spikenard
Sandalwood
Sumac
Sweet Orange alcohol
Vervain
walnut

Products containing l-tryptophan

Designs For Health Amino Acid Supreme™
Thorne Amino Complex Berry
Thorne Amino Complex Lemon
Pure Encapsulations Amino-NR
Pure Encapsulations Amino Replete
Metagenics BioPure Protein® Powder
Pure Encapsulations Cognitive Aminos
Pure Encapsulations Essential Aminos
Klean Athlete Klean Essential Aminos + HMB®
Klean Athlete Klean Isolate ™
Pure Encapsulations L-Tryptophan
Pure Encapsulations L-Tryptophan
Douglas Laboratories L-Tryptophan
Douglas Laboratories Muscle Protect™ with HMB®
Metagenics Perfect Protein® Pea & Rice Chocolate Powder
Metagenics Perfect Protein Pea & Rice Vanilla Powder
Metagenics Perfect Protein Whey Chocolate
Metagenics Perfect Protein Whey Vanilla
Thorne RecoveryPro NSF
Metagenics Ultra Glucose Control® Chocolate
Metagenics Ultra Glucose Control Chocolate
Metagenics Ultra Glucose Control Vanilla
Metagenics Ultra Glucose Control Vanilla
Metagenics UltraGI Replenish® Chocolate
Metagenics UltraGI Replenish Chocolate
Metagenics UltraGI Replenish Vanilla
Metagenics UltraGI Replenish Vanilla
Metagenics UltraInflamX Plus 360°® Chocolate/Orange
Metagenics UltraInflamX Plus 360° Mango
Metagenics UltraInflamX Plus 360° Mango
Metagenics UltraInflamX Plus 360° Orange
Metagenics UltraInflamX Plus 360° Original Spice
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Metagenics UltraMeal Advanced Protein® Dutch Chocolate
Metagenics UltraMeal Advanced Protein French Vanilla
Metagenics UltraMeal Advanced Protein Plain
Metagenics UltraMeal Cardio 360°® Pea/Rice Chocolate
Metagenics UltraMeal Cardio 360° Pea/Rice Vanilla