Some concerns raised; more research may be needed
Safety assessments compiled from FDA, EFSA, FSA, and 7 other regulatory agencies. This information is for educational purposes — consult a healthcare professional for dietary advice.
L-Cysteine
Last reviewed: April 2026 · Data sourced from WHO JECFA, FDA, EFSA, and 7 other regulatory agencies
At a Glance
Quick Answer
L-Cysteine (E920) is rated "Use Caution" according to current evidence. It is approved in the EU and approved in the US. This additive is currently approved in all four major markets (US, EU, UK, Japan).
On This Page
What is L-Cysteine?
Amino acid. Can be derived from human hair or duck feathers
L-Cysteine is classified as a Flour Treatment Agent additive. It is currently approved in all major regulatory markets. Some debate exists around its long-term safety profile.
Regulatory Status by Country
🇺🇸 United StatesUS
Approved (GRAS)US name: L-Cysteine
GRAS in US
🇪🇺 European UnionEU
ApprovedAmino acid. Can be derived from human hair or duck feathers
🇬🇧 United KingdomUK
Same as EU pre-BrexitUK retained EU food additive regulations post-Brexit with some modifications
🇯🇵 Japan
ApprovedJapanese: L-システイン
Approved as flour treatment agent
🇨🇦 CanadaCA
ApprovedGenerally aligned with US FDA. Regulated by Health Canada.
🇦🇺 Australia/NZAU/NZ
ApprovedGenerally aligned with EU standards. Regulated by FSANZ.
🇮🇳 India
ApprovedWidely approved internationally. Regulated by FSSAI.
🇰🇷 South KoreaKR
ApprovedGenerally aligned with Japanese standards. Regulated by MFDS.
🇧🇷 Brazil
ApprovedGenerally aligned with Codex/US standards. Regulated by ANVISA.
🇨🇳 China
ApprovedPermitted under GB 2760 national standard.
Note: Canada, Australia/NZ, India, South Korea, Brazil, and China statuses are inferred from international regulatory patterns. Always verify with the relevant national authority.
Expert Analysis
L-Cysteine is classified as a flour treatment agent in the food additive regulatory framework. While approved for use, some scientific studies have raised questions that warrant ongoing monitoring. This additive is approved across multiple major regulatory markets worldwide, suggesting broad scientific consensus on its safety profile. Some debate exists around L-Cysteine, though the weight of evidence supports its current regulatory status. Sensitive individuals may wish to monitor their consumption. As with all food additives, moderation is key. Consult healthcare professionals for personalized dietary advice.
Is L-Cysteine safe?
L-Cysteine has a safety rating of "Use Caution". Some concerns raised; more research may be needed
Is L-Cysteine vegan?
L-Cysteine is generally considered vegan-friendly, though sourcing may vary.
Is L-Cysteine banned in Europe?
No, L-Cysteine is Approved in the EU.
What is L-Cysteine made from?
Amino acid. Can be derived from human hair or duck feathers
Did You Know?
L-Cysteine (E920) used in bread can be derived from human hair, duck feathers, or produced by fermentation.
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Frequently Asked Questions
Is L-Cysteine safe?
Is L-Cysteine banned in any country?
What is L-Cysteine used for?
Sources & References
Regulatory data for L-Cysteine is sourced from the following agencies:
- FDA: Substances Added to Food (formerly EAFUS)
- EFSA: Food Additives Database
- FSA: Approved Additives and E Numbers
- MHLW: Standards for Use of Food Additives
- Health Canada: Lists of Permitted Food Additives
- FSANZ: Food Additives
- FSSAI: Food Safety and Standards
- MFDS: Food Additives Standards
- ANVISA: Food Additives Legislation
- GB 2760: National Food Safety Standard
- WHO JECFA: International Safety Evaluations
- CSPI: Chemical Cuisine — Food Additive Safety Ratings
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