L-cysteine or cystine stated as from feathers or poultry

This L-cysteine is made from feathers. Feathers from poultry that was not Islamically slaughtered count as maytah, which Darul Fatwa's school holds to be najis. Without halal certification we presume the animal was not Islamically slaughtered, so this is Haram. A halal certificate, kosher certification from an agency we accept, or proof of a halal source such as fish, zabihah or plant would change that. If the certifier allows machine slaughter or stunning, it is Doubtful · high.

Food	Cosmetics & personal care	Medicine
Haram	Haram	Medicine note

Concern

From an animal, slaughter not confirmed

Known to come from an animal, and the animal's slaughter isn't confirmed. Doubtful meat is not permissible.

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)

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

Darulfatwa – Islamic High Council of Australia · Purification from the Najas-Filth

Among what is considered najas-filthy are urine, feces, blood, puss, vomit, alcohol, and the maytah , including its bones and hair.

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

Certification Center "Halal" · Центр сертифікації «Халяль» (home page)

Заборонених тварин, птахів, земноводних тощо, їх м'ясо та будь-які інші частини (жир, кістки, шкіра, шерсть, внутрішні органи, пір'я, пазурі, кров та ін.);

halal.ua's own English “Prohibited animals, birds, amphibians, etc., their meat and any other parts (fat, bones, skin, wool, internal organs, feathers, claws, blood, etc.);”

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

Darulfatwa – Islamic High Council of Australia · متن أبي شجاع في الفقه الشافعي

وعظم الميتة وشعرها نجس إلا الآدمي.

Translation “The bones and hair of maytah are najis, except those of a human.”

Source page · archived copy · retrieved Sep 22, 2026

All sources →

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