Miscellaneous additive
Is E641 (L-Leucine) halal?
L-Leucine: An essential amino acid, when derived from plant sources.
L-Leucine: An essential amino acid, when derived from plant sources.
What we know
Named sources are on this page. Classification: Source-dependent.
What we don’t know
The pack in your hand does not, by itself, name the raw material or process.
Why it matters
Doubtful until the source is known (mashbooh)
What to verify
For E641 in this product: is it fermented, synthetic, or keratin/hair-derived?
What the sources say
L-Leucine: An essential amino acid, when derived from plant sources.
What to ask the manufacturer
A recognised halal mark or a vegan declaration can settle this instead. If you email the brand, send one specific question:
For E641 in this product: is it fermented, synthetic, or keratin/hair-derived?
Quick facts
| E-number | E641 |
|---|---|
| Name | L-Leucine |
| Also on labels as | E641, L-leucine, leucine amino acid, INS 641 |
| Additive class | Miscellaneous additive |
| Classification | Source-dependent |
| Source last accessed | 2026-08-21 |
Common questions
Is E641 (L-Leucine) halal?
L-Leucine is classified as Source-dependent. L-Leucine: An essential amino acid, when derived from plant sources.
Is L-Leucine halal or haram?
On the evidence cited on this page, L-Leucine 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-Leucine called on ingredient labels?
It can appear as: E641, L-leucine, leucine amino acid, INS 641.
Why isn't there a single yes/no answer for E641?
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.
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