Depends on the source
- Usually made from
- Hair, feathers or fermentation
- Used as
- flour treatment agent
- Vegan
- Depends on the source
Not considered halal when made from human hair; versions made by fermentation are.
What is E920?
L-cysteine is an amino acid that softens dough so it mixes faster and stretches more easily. It is made by breaking down keratin, the protein in poultry feathers, or by fermentation with bacteria. The food grade is usually sold as L-cysteine hydrochloride.
Why it's marked “Depends on the source”
The status depends on the raw material. Versions made by fermentation contain no animal material. Keratin from feathers raises the question of which birds were used and how they were killed. Human hair has also been used as a source; it is not accepted, and EU rules forbid it.
Where views differ
Using human hair is widely rejected out of respect for human dignity. For feathers, some scholars accept keratin from poultry feathers because it is heavily processed and changed, while others want it from halal-slaughtered birds or avoid it. Fermentation-made L-cysteine is generally accepted.
How to check the label
Look for “produced by fermentation”, “non-animal origin”, a vegan mark or a halal certificate from a recognised body. For unpacked bakery bread, ask which flour improver is used, since there is often no ingredient list.
Where you'll find it
- bread and rolls
- pizza bases
- crackers
- frozen dough
- savoury flavourings
Good to know
- EU specifications for E920 state that human hair may not be used as a source for this substance.
- EFSA opinions describe L-cysteine made by hydrolysis of keratin from poultry feathers and by fermentation with non-genetically modified E. coli strains.
Similar additives
See all 89 E-numbers in the halal checker
This list describes where additives usually come from. It isn't a religious ruling, and manufacturers can change their sources. Last reviewed: 14 October 2026.
Sources
- EU additive specifications, Regulation (EU) No 231/2012 (E 920)
- EFSA opinion on L-cysteine made by fermentation (2020)
Frequently asked questions
Is E920 halal?
Depends on the source. The status depends on the raw material. Versions made by fermentation contain no animal material. Keratin from feathers raises the question of which birds were used and how they were killed. Human hair has also been used as a source; it is not accepted, and EU rules forbid it.
What is E920 made from?
L-cysteine is an amino acid that softens dough so it mixes faster and stretches more easily. It is made by breaking down keratin, the protein in poultry feathers, or by fermentation with bacteria. The food grade is usually sold as L-cysteine hydrochloride.
Is E920 vegan?
It depends on the source. E920 can be made from plant or animal material, so look for a vegan or vegetarian label.