Is L-cysteine (E920) vegetarian?
Red — not vegetarian
No — not unless the label says otherwise. L-cysteine (920/921) — usually from feathers or hair unless synthetic. LabelSense marks a pack containing it Red (not vegetarian), unless the label pins it to a non-animal source, e.g. "synthetic l-cysteine".
By diet
| Diet | Verdict |
|---|---|
| Vegetarian No meat, no fish, no egg. | Not suitable |
| Eggetarian Vegetarian, and egg is fine. | Not suitable |
| Pescetarian Vegetarian plus fish and seafood. | Not suitable |
| Vegan No dairy, honey or any animal by-product. | Not suitable |
| Jain No onion, garlic, root vegetables, fungi or honey. | Not suitable |
| Swaminarayan Vegetarian, without the onion–garlic family. | Not suitable |
These verdicts are exactly what LabelSense shows for a label listing “l-cysteine” and nothing else. On a real pack, the other ingredients count too.
What settles the source
Only a phrase on the label that pins it to a non-animal source changes the verdict. A general halal mark does not.
Phrases LabelSense accepts: “synthetic l-cysteine”, “fermentation-derived l-cysteine”.
How it appears on labels
l-cysteinecysteinecystineE920920E921921
Related ingredients
Results come from reading the label. Always check the pack yourself, especially for allergies. Ingredient sources can change without notice — when a label doesn't settle it, ask the manufacturer.
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