Flavor ingredient regulatory record

L-Phenylalanine

L-Phenylalanine is an amino acid in the sweet family, FEMA GRAS under FEMA number 3585 (CAS 63-91-2). Its odor is sweet, nutty, creamy, faintly floral.

FEMA
3585
CAS
63-91-2
JECFA
1428
EU FL
17.018
Formula
C9H11NO2
EC
200-568-1

GRAS status: FEMA GRAS, publication 11. Recorded by FDA in the Substances Added to Food inventory under CAS 63-91-2.

Structure

2D structure of L-Phenylalanine
Structure of L-Phenylalanine, C9H11NO2. Drawn from the canonical SMILES.

Identity

IUPAC name (2S)-2-amino-3-phenylpropanoic acid
CAS number 63-91-2
FEMA number 3585
Molecular formula C9H11NO2
Molecular weight 165.19 g/mol
SMILES N[C@@H](Cc1ccccc1)C(=O)O
InChIKey COLNVLDHVKWLRT-QMMMGPOBSA-N
PubChem CID 6140
EC number 200-568-1
FDA UNII 47E5O17Y3R
EPA DTXSID DTXSID4040763
Chemical class Amino acid
Boiling point 295 °C
Flash point 135 °C

Also known as: Alanine, phenyl-, L-, (S)-α-Aminohydrocinnamic acid, (S)-α-Amino-β-phenylpropionic acid, Phenylalanine, β-Phenyl-L-alanine, β-Phenyl-α-alanine, Antibiotic FN 1636, Benzenepropanoic acid, α-amino-, (S)-, Phenyl-α-alanine, 3-Phenyl-L-alanine, 3-Phenylalanine, (S)-Phenylalanine.

Can L-Phenylalanine be labeled natural?

Nature makes L-Phenylalanine, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial L-Phenylalanine, same molecule. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic L-Phenylalanine identical-to-natural.

United States
Natural or artificial, by process
European Union and UK
Natural only from natural material
Mercosur and Mexico
Natural or identical-to-natural

How each market defines the classes: natural vs artificial flavor under 21 CFR 101.22.

Regulatory status, with citations

United States

L-Phenylalanine is FEMA GRAS under FEMA number 3585. It is cited in the Code of Federal Regulations at 21 CFR 172.320.

21 CFR 172.320

European Union and United Kingdom

Listed on the Union List of flavouring substances as FL 17.018, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 1428, evaluated at the 63rd meeting in 2004. No safety concern at current levels of intake when used as a flavouring agent.

JECFA monograph

Other US flags

Not on the California Proposition 65 list.

TSCA Inventory status

A flavor ingredient is also an industrial chemical. L-Phenylalanine appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 63-91-2, where EPA names it L-Phenylalanine.

Active in US commerce

EPA designates this substance active, so no Notice of Activity Form B is required before manufacturing. What active and inactive mean.

EPA publishes no regulatory flags on this listing. What the flags mean.

From the EPA non-confidential TSCA Inventory, July 2026 release. EPA also maintains a confidential portion it does not publish. Search the Inventory by CAS number.

Odor and taste

Odor: Sweet, nutty, creamy, faintly floral.

Taste: Sweet, umami, slightly bitter.

Where it is used

L-Phenylalanine is used in beverage, confection, nut flavors, dairy and protein supplements, typically as a sweet note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to L-Phenylalanine by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
DL-Phenylalanine3726100%In nature
Benzyl formate214577%In nature
4-Phenyl-2-butanol287977%In nature
3-Phenylpropionic acid288968%In nature
Phenoxyacetic acid287267%In nature

More amino acids in this index

Glycine · DL-Phenylalanine · L-Threonine · L-Alanine · L-Alanyl-L-Glutamine · Alanine

L-Phenylalanine FAQ

Is L-Phenylalanine FEMA GRAS?

Yes. The FEMA Expert Panel lists L-Phenylalanine as GRAS under FEMA number 3585. The Code of Federal Regulations lists it at 21 CFR 172.320.

What are the FEMA and CAS numbers for L-Phenylalanine?

L-Phenylalanine is FEMA 3585, CAS 63-91-2. Its flavor category is sweet.

How is L-Phenylalanine described, and where does it show up?

Flavorists describe L-Phenylalanine as sweet, nutty, creamy, faintly floral. On the palate it is sweet, umami, slightly bitter. It is used in beverage, confection, nut flavors, dairy and protein supplements.

What did JECFA conclude about L-Phenylalanine?

JECFA evaluated L-Phenylalanine at the 63rd meeting in 2004 under JECFA number 1428. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.

Is L-Phenylalanine on the EU Union List?

Yes. FL 17.018 is the Union List entry for L-Phenylalanine, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.

Does L-Phenylalanine count as natural in the US and the EU?

The process decides for L-Phenylalanine. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic L-Phenylalanine is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic L-Phenylalanine identical-to-natural.

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Sources and attribution. The identity and regulatory facts on this page are taken from the FDA Substances Added to Food inventory, a US government record, which lists this substance as L-PHENYLALANINE under CAS 63-91-2 and carries its FEMA number, its JECFA flavor number and its 21 CFR citations. The inventory is searchable at FDA. FDA records its technical effect as flavor enhancer, flavoring agent or adjuvant, nutrient supplement.

A FEMA GRAS conclusion is reached by the Expert Panel of the Flavor and Extract Manufacturers Association of the United States, and the FEMA number names that conclusion. FEMA publishes its own entry for this substance in the FEMA Flavor Library, which is the authoritative record of what the Panel decided and is worth reading alongside this page.

Ambrose Compliance is not affiliated with, endorsed by, or sponsored by FEMA. FEMA and FEMA GRAS are used here as identifiers for a published regulatory determination, not as marks of any relationship between FEMA and Ambrose.

About this page. Facts come from the FDA Substances Added to Food inventory, the Code of Federal Regulations, the EPA TSCA Inventory, the EU Union List, JECFA and the Ambrose database, with FEMA's published determination cited where it applies; parts of the text are written by Ambrose AI, which can make mistakes. Check the cited source before relying on anything here. This is not regulatory or legal advice.