Ingredient profile
L-cystine
Our sources have no reference data on this ingredient — a gap in our data, never a verdict. Also written as L-Cystine, L-CYSTINE.
Where each list lands
Funding shown- Safe
Greenlens Ingredient Scan
Independent
No EU-regulated hazard recognized for this ingredient.
- Safe
Greenlens Precautionary Screen
Independent
No listed hazard trait recognized for this ingredient.
- Safe
Greenlens Tolerance Screen
Independent
No prohibited or high-risk classification for this ingredient.
Also screened — not on these lists
- Health Canada Ingredient Hotlist
- California Proposition 65
- US NTP Report on Carcinogens
- IARC Monographs
- ANSES Endocrine Disruptors
- EU Microplastics Restriction
- EU Harmonised Classification (CLP Annex VI)
Where regulators stand
Shown side by side, never combinedEach jurisdiction is reported on its own terms, from its own official lists. Where they disagree, that disagreement is the finding. Absence from a list is never a safety claim.
European Union
No listing foundNot on the lists we hold for this jurisdiction. That is an absence of a listing, not a safety finding.
Checked: EU Cosmetics Regulation Annexes II, III, V and VI; CLP Annex VI harmonised classification; ECHA SVHC Candidate List (cosmetics-relevant subset).
Canada
No listing foundNot on the lists we hold for this jurisdiction. That is an absence of a listing, not a safety finding.
Checked: Health Canada Cosmetic Ingredient Hotlist.
California
No listing foundNot on the lists we hold for this jurisdiction. That is an absence of a listing, not a safety finding.
Checked: OEHHA Proposition 65 list.
