E921 L-cystine: Halal or Haram?

Doubtful

Closely related to E920, used in bakery. E921 (L-cystine) is doubtful.

Why it is doubtful

Same source question as E920.

Halal or not depends on what it is made from

E921 is Mushbooh: Halal when it is made by fermentation, synthetically or from bird feathers, not when it comes from human hair or pig bristles.

Made from	Verdict	Why
Made by fermentation	Halal	No animal involved
Made synthetically	Halal	No animal involved
Duck or poultry feathers	Halal	Most scholars hold bird feathers to be pure
Human hair	Haram	Using the human body is not permitted
Pig bristles	Haram	Pork
Halal-certified product	Halal	A certifier checked the source
Source not stated on the label	Mushbooh	The label does not say which

Scholarly view

Schools of law

Hanafi · Maliki · Shafi'i · HanbaliAll four prohibit L-cystine made from human hair, because using the human body goes against the dignity (karamah) God gave the human being, and all four accept it from bird feathers, or from synthesis and fermentation. If a forbidden source had been chemically changed into a new substance (istihala) they would split, Hanafi and Maliki accepting it and Shafi'i and Hanbali not, but that hardly arises, since industry mainly uses feathers, fermentation and synthesis.

Depends on source

Certification bodies

SANHASANHA lists E921 (L-cystine) as doubtful (mushbooh), because it is made from horse hair or synthetically.SANHA — E921 ↗

Doubtful

Dept. of Islamic Development Malaysia / Halal Food Authority, UKE921 is cleared from a feather, fermentation or synthetic source; a human-hair or pig source is rejected, so the source must be verified.JAKIM — Halal Malaysia Portal ↗HFA FAQ ↗

Verify source

Fatwa councils, scholars and other sources

Askimam (Mufti Ebrahim Desai)L-cystine made from human hair is not Halal. Made synthetically or from chicken and duck feathers, it is Halal.Askimam — L-cystine ↗

Depends on source

From pig bristlesNothing taken from the pig may be eaten, so L-cystine made from pig bristles is not permitted.

Impermissible

Only views with a published source are listed.

Where you meet it

Bread and dough improvers.

What to do in the shop

Look for a product that names the source, says plant-based or vegan, or carries a Halal certificate. If nothing on the packet settles it, the manufacturer can tell you, and their answer is the only thing that turns E921 from a question into an answer.

A status here describes the additive in general, and a specific product can be different. The same number can be made from plant or animal material depending on the manufacturer, and the label does not say which.

Questions people ask

Is E921 Halal?

E921 (L-cystine) is doubtful. Same source question as E920.

How do I know if the E921 in a product is Halal?

Only the manufacturer can tell you which source they used, unless the packet says plant-based, vegan, or carries a Halal certificate.

Related additives

E920 L-cysteine · Doubtful
E913 Lanolin · Doubtful
E904 Shellac · Doubtful

See all E-numbers →

Read this in Turkish: E921 helal mi? →

Products we asked the manufacturer about →

Check a product, not just a number

An additive's status describes the additive in general. What matters is the whole ingredient list on the packet in your hand.

This is information, not a fatwa. These statuses combine published scholarly positions with ingredient analysis, and they can be incomplete or out of date. For anything that matters, confirm with the manufacturer and with a qualified authority.