L-cysteine or cystine (E920, E921), source not stated

L-cysteine (a dough conditioner) can be made from feathers, hair or by fermentation, and the label doesn't say which. When the origin is only a possibility, the ruling returns to the original permissibility, though it is better avoided, so we mark it Doubtful · low.

Food	Cosmetics & personal care	Medicine
Doubtful · low	Doubtful · low	Doubtful · low

Concern

Possibly from an animal

The source could be plant, synthetic or animal. Food other than meat is allowed unless shown otherwise, so a doubt like this doesn't make it forbidden. It's still better avoided.

What clears it

A halal certificate from a certifier that meets our standard
Vegan certification (never clears alcohol)
A written reply from the brand, reviewed by Zulal (valid 12 months)
Kosher certification from an agency on our accepted list (animal ingredients and meat only; never alcohol, pork, carmine or shellac)

Also listed as: E920, E921

What our sources say

Darulfatwa – Islamic High Council of Australia · Drinks…

The important thing is that no Najas (filth) ingredient such as alcohol is used in the production of these soft drinks. However, if someone has any doubts about the use of such najis ingredients, then it is more complete for him out of wara^ to avoid such drinks.

Source page · archived copy · retrieved Sep 22, 2026

Certification Center "Halal" · Что запрещено употреблять в пищу?

Если человек точно не знает или сомневается, как именно было зарезано животное, тогда ему нельзя употреблять это мясо в пищу.

Translation “If a person does not know for certain, or is in doubt, how exactly the animal was slaughtered, then he may not eat this meat.”

Page of the older WordPress site (2015); no longer online. · Source page · archived copy · retrieved Sep 22, 2026

Darulfatwa – Islamic High Council of Australia · Drinks…

Islam though has a strict ruling regarding the meat. If someone has such doubt regarding the source of meat, whether it has been slaughtered Islamically or not, then it is haram to consume or eat this meat due to this doubt. This ruling of the meat becoming Haram on doubting its Islamic source is a matter of Ijma^ (scholarly concensus).

Source page · archived copy · retrieved Sep 22, 2026

Certification Center "Halal" · Что запрещено употреблять в пищу?

А что касается других продуктов, например, молочных, кондитерских, то в отличие от мяса, если возникает сомнение в том, были ли они произведены согласно Шариʻату, то их не запрещено употреблять в пищу.

Translation “As for other products, for example dairy or confectionery, unlike meat, if there is doubt whether they were produced according to the Shari'ah, they are not forbidden to eat.”

Page of the older WordPress site (2015); no longer online. · Source page · archived copy · retrieved Sep 22, 2026

Darulfatwa – Islamic High Council of Australia · سؤال : من أكثر المسائل شهرة عن الهلالي أنه أحل أكل اللحم المشكوك فيه فما الحكم ؟

وأيضاً لايحلّ أكل ما لم يعلم هل ذابحه هو ممن يصحّ تذكيته أم لا، لأن أمر اللحم في هذا أشد من أمر الجبن والحلوى ونحوهما، فإنه إذا شك شخص هل في الحلوى التي بين يديه أو الجبن الذي بين يديه نجاسة جاز له الأكل منه مع الشك،

Translation “Also, it is not lawful to eat what is not known to have been slaughtered by someone whose slaughter is valid, because the matter of meat in this is stricter than the matter of cheese, sweets and the like. For if a person doubts whether there is najasah in the sweets in front of him or in the cheese in front of him, it is permissible for him to eat from it despite the doubt,”

Source page · archived copy · retrieved Sep 22, 2026

Certification Center "Halal" · Что запрещено употреблять в пищу?

Теологи Ислама всех времен единодушно подтвердили, что недопустимо употреблять в пищу мясо, если человек сомневается, халяль это или харам. В частности об этом говорили такие великие теологи шафиʻитского мазhаба как Ибн Хаджар Аль-hайсамий, Ас-Суютый, а также теолог маликитского мазhаба Аль-Карафий и другие.

Translation “The theologians of Islam of all times unanimously confirmed that it is not permissible to eat meat if a person doubts whether it is halal or haram. In particular, this was stated by such great theologians of the Shafi'i madhhab as Ibn Hajar al-Haytami and al-Suyuti, and by the Maliki theologian al-Qarafi, and others.”

Page of the older WordPress site (2015); no longer online. · Source page · archived copy · retrieved Sep 22, 2026

All sources →

Other sources: www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184/subpart-B/section-184.1271

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