Miscellaneous additive

Is E920 (L-Cysteine) halal?

The additive that makes commercial bread dough workable. Its cheapest historical source was human hair — which is why this otherwise obscure amino acid has a whole fiqh discussion attached.

Source-dependentDoubtful until the source is known (mashbooh)

A dough conditioner with four possible sources. Human hair and porcine bristle are haram; synthetic is halal; poultry feathers from halal birds are accepted by some scholars and rejected by others. JAKIM requires source documentation.

The detail

L-Cysteine is an amino acid used to relax dough in industrial baking. MuslimConsumerGroup documents the source hierarchy: haram from human hair, halal from synthetic material, and genuinely disputed when from chicken or duck feathers — one school of ulema accepts it, another does not. HalalExpo's checker records the JAKIM position: human hair haram, porcine haram, poultry feathers from halal birds halal, synthetic halal, with source documentation required. IFANCA lists cysteine hydrochloride among doubtful bagel ingredients. Modern Western industrial supply has shifted heavily toward fermentation and synthetic routes, but 'shifted' is not 'documented' — the label still does not say.

What the sources say

Mushbooh, Haraam if it is obtained from human hair, Halal if it is made from Halal synthetic material. The third source is from chicken/duck feathers. There is difference of opinions among different Islamic scholars.
Mashbooh (conditional) Haram from human hair; halal from synthetic; poultry feathers disputed between scholars. Halal Authority India (certifier reference table · grade B: certifier guidance · accessed 2026-08-21)
JAKIM requires source documentation. Human hair = haram. Porcine = haram. Poultry feathers from halal birds = halal. Synthetic = halal.
Mashbooh (JAKIM requires documentation) Human hair haram; porcine haram; poultry feathers from halal birds halal; synthetic halal. HalalExpo (secondary aggregator · grade C: secondary reference · accessed 2026-08-21)
Bagel — Cysteine Hydrochloride, Enzymes, Folic Acid, Niacin
Mashbooh (investigate) Cysteine hydrochloride listed among doubtful bagel ingredients. IFANCA (Islamic Food and Nutrition Council of America) (certifier guidance · grade A: primary source · accessed 2026-08-21)

Where you will run into it

How to check it yourself

A halal-certified bakery product settles it. Otherwise ask the manufacturer for the L-cysteine source: synthetic/fermentation is the answer you want. Feather-derived splits scholarly opinion — defer to your own school.

Quick facts

E-numberE920
NameL-Cysteine
Also on labels asl-cysteine, cysteine, l-cysteine hydrochloride, cysteine hydrochloride, e921
Additive classMiscellaneous additive
ClassificationSource-dependent
Last verified2026-08-21

Common questions

Is E920 (L-Cysteine) halal?

L-Cysteine is classified as Source-dependent. A dough conditioner with four possible sources. Human hair and porcine bristle are haram; synthetic is halal; poultry feathers from halal birds are accepted by some scholars and rejected by others. JAKIM requires source documentation.

Is L-Cysteine halal or haram?

On the evidence cited on this page, L-Cysteine is source-dependent. Doubtful until the source is known (mashbooh) Every position is attributed to a named certifier or scholarly body with a link, so you can verify it directly.

What else is L-Cysteine called on ingredient labels?

It can appear as: l-cysteine, cysteine, l-cysteine hydrochloride, cysteine hydrochloride, e921.

Why isn't there a single yes/no answer for E920?

Because the ruling depends on information the label does not carry — the source material, the production route, or which scholarly position you follow. This page shows each named position with a link so you can check it yourself.

Where does this page's information come from?

Every position on this page is attributed to a named certifier or scholarly body with a direct link, listed under 'What the sources say'. Muttoo aggregates and cites; it does not issue rulings.

Related lookups

Record e920-l-cysteine · last verified 2026-08-21 · report an error