What is the NOAEL for L-Tryptophan?
L-Tryptophan has 31 NOAEL studies in the database. The lowest reported value is 664 mg/m3 via inhalation in Human. Source: ToxValDB_GESTIS_DNEL.
NOAEL Data
REACH Registered
Cosmetic Ingredient
L-Tryptophan
Also known as: (S)-2-Amino-3-(1H-indol-3-yl)propanoic acid, Triptophan, L-TRYPTOPHAN (AMINO ACID), Alanine, 3-indol-3-yl-, L-alpha-Aminoindole-3-propionic acid (+15 more)
CAS 73-22-3
L-Tryptophan (CAS 73-22-3) is a chemical substance. Key regulatory status: REACH registered, 4 regulatory/inventory lists, cosmetic ingredient cross-reference; source data from EPA ToxValDB, EPA CPDat, ECHA REACH.
SOURCE
noael studies public
NOAEL studies
31
SOURCE
chemical inventory jurisdictions
Regulatory lists
4
SOURCE
eu clp annex vi
GHS signal
Not classified
Chemical Identity
CAS, identifiers, formula, and alternate names for the matched substance record.
SOURCE
DSSTox identifiers
26 fields
Name
L-Tryptophan
CAS Number
73-22-3
DTXSID
DTXSID5021419
Molecular Formula
C11H12N2O2
InChI Key
QIVBCDIJIAJPQS-VIFPVBQESA-N
Monoisotopic Mass
204.089878
Synonyms
(S)-2-Amino-3-(1H-indol-3-yl)propanoic acidTriptophanL-TRYPTOPHAN (AMINO ACID)Alanine, 3-indol-3-yl-L-alpha-Aminoindole-3-propionic acidalpha'-Amino-3-indolepropionic acidalpha-Amino-3-indolepropionic acid, L-EINECS 200-795-61H-Indole-3-propanoic acid, alpha-amino-, (S)-Indole-3-propionic acid, alpha-amino-NCI-C01729Propionic acid, 2-amino-3-indol-3-yl-
Functional Uses
Industrial and product-use categories associated with this substance.
SOURCE
EPA CPDat
1 records
Flavouring and nutrient
Regulatory Lists
Inventory, screening, and regulatory list matches from public chemical databases.
SOURCE
EPA CPDat
4 records
| List | Keyword | Source |
|---|---|---|
| active_ingredient; Europe; Pesticides | European Commission | CPCat |
| inert_ingredient; Pesticides | EPA | CPCat |
| inert_ingredient; non_food_use; Pesticides | EPA | CPCat |
| food_additive; Substances Added to Food (formerly EAFUS) (2/2019) | FDA | United States Food and Drug Administration (FDA) |
NOAEL Studies
Toxicology endpoints rendered from public NOAEL study rows.
SOURCE
NOAEL studies
Showing 31 of 31 studies
| Value | Unit | Endpoint | Route | Species | Source |
|---|---|---|---|---|---|
| =664 | mg/m3 | DNEL systemic | inhalation | Human | ToxValDB_GESTIS_DNEL |
| 8DUH1N11BX | UNII | FDA UNII substance identifier | - | - | openFDA substances |
| 8DUH1N11BX | UNII | FDA UNII substance identifier | - | - | openFDA substances |
| 8DUH1N11BX | UNII | FDA UNII substance identifier | - | - | openFDA substances |
| 8DUH1N11BX | UNII | FDA UNII substance identifier | - | - | openFDA substances |
| >5.17 | mg/L | LC50 | Inhalation | - | NTP_ICE_acute_inhalation |
| >5.75 | mg/L | LC50 | Inhalation | - | NTP_ICE_acute_inhalation |
| >2000 | mg/kg bw | LD50 | oral | Rat | NTP_ICE_acute_oral |
| >2150 | mg/kg bw | LD50 | oral | Rat | NTP_ICE_acute_oral |
| >16000 | mg/kg bw | LD50 | oral | Rat | NTP_ICE_acute_oral |
| =1250 | mg/kg bw/day | LEL | oral | Rat | ToxValDB_ToxRefDB |
| =1250 | mg/kg bw/day | LEL | oral | rat (fischer; Fischer 344) | ToxRefDB_ToxRefDB_v3_pod.csv |
| >2500 | mg/kg bw/day | LEL | oral | Rat | ToxValDB_ToxRefDB |
| >2500 | mg/kg bw/day | LEL | oral | rat (fischer; Fischer 344) | ToxRefDB_ToxRefDB_v3_pod.csv |
| =3750 | mg/kg bw/day | LEL | oral | Mouse | ToxValDB_ToxRefDB |
| =3750 | mg/kg bw/day | LEL | oral | mouse (b6c3f1; B6C3F1) | ToxRefDB_ToxRefDB_v3_pod.csv |
| - | unitless | Model Score | - | - | NTP_ICE_endocrine |
| >- | mg/kg bw/day | NEL | oral | rat (fischer; Fischer 344) | ToxRefDB_ToxRefDB_v3_pod.csv |
| 200 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 400 | mg/kg bw/day | NOAEL | oral | swine | COSMOS_DB |
| 500 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 1000 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 1153 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 1250 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 1600 | mg/kg bw/day | NOAEL | oral | swine | COSMOS_DB |
| 2000 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 3750 | mg/kg bw/day | NOAEL | oral | mouse | COSMOS_DB |
| 5000 | mg/kg bw/day | NOAEL | oral | rat | COSMOS_DB |
| 7500 | mg/kg bw/day | NOAEL | oral | mouse | COSMOS_DB |
| =2000 | mg/kg bw/day | NOEL | oral | Rat | ToxValDB_ECOTOX |
| 50000 | ppm | Top dose | - | Rat | NTP_ICE_cancer |
Showing 31 of 31 studies
REACH Registration
Registration status from the ECHA REACH registered substances database.
SOURCE
ECHA (EU)
1 records
| Status | Name | EC Number | Link |
|---|---|---|---|
| Registered | L-tryptophan | 200-795-6 | ECHA overview → |
Cosmetic Safety Profile
Same-CAS cosmetic ingredient record for cross-vertical context.
SOURCE
CosIng / Ingredients DB
EU Status
permitted
Max
-
Category
Amino Acid
Pharmaceutical Data
Same-CAS pharmaceutical records from drug and bioactivity sources.
SOURCE
EMBL-EBI ChEMBL
TRYPTOPHAN
ChEMBL Phase
4
Adverse Events
18
Bioactivity
6
Cannabis Data
Same-CAS cannabis compliance and lab records where available.
SOURCE
Cannabis regulatory / lab data
efsa substances
1 cannabis record found in efsa substances.
View full cannabis profile →Frequently Asked Questions
What regulatory lists include L-Tryptophan?
L-Tryptophan appears on 4 regulatory/inventory lists including active_ingredient; Europe; Pesticides, inert_ingredient; Pesticides, inert_ingredient; non_food_use; Pesticides, and 1 more. Source: EPA CPDat.
Is L-Tryptophan used in cosmetics?
Yes, L-Tryptophan is also indexed as a cosmetic ingredient under the name L-Tryptophan. View the full cosmetic safety profile on the ingredient page for detailed safety data, SCCS opinions, and regulatory status.
Where does the safety data for L-Tryptophan come from?
Safety data is sourced from EPA ToxValDB, EPA CPDat, EPA DSSTox, ECHA REACH, CosIng / Ingredients DB, ChEMBL / DailyMed, cannabis regulatory/lab databases. All data traces to primary regulatory sources and is updated from official government databases.
Is L-Tryptophan used outside industrial chemicals?
L-Tryptophan also appears in cosmetics, pharmaceutical, cannabis databases.