l-cysteine

Trade name: cysteine hydrochloride

Small moleculeapproved

Approved

Oct 22, 1986

Cysteine (cysteine hydrochloride is a salt) is a thiol-containing amino acid that is oxidized to form cystine. Cysteine is synthesized from methionine via the trans-sulfuration pathway in the adult, but newborn infants lack the enzyme, cystathionase, necessary to effect this conversion. Therefore, cysteine is generally considered to be an essential amino acid in infants. — NCATS

Clinical trial activity

13 trials · 22 clinical orgs · 9 marketing orgs

Phase 1

Phase 2

Phase 3

Phase 4

Earliest trial started May 1, 1996 (NCT00004940)

Timeline

1980s

Oct 22, 1986
Abbott — Earliest FDA Approval
Oct 22, 1986
Hospira — NDA Secondary Org
Oct 22, 1986
Abbott — NDA Organization

1990s

Jan 1, 1996
Earliest Phase 3 Sponsor(trial)

2000s

Jan 1, 2006
Earliest Phase 2 Sponsor(trial)

2010s

Jan 1, 2015
Earliest Phase 1 Sponsor(trial)
Apr 16, 2019
Exela Pharma Sciences, LLC. — NDA Secondary Org
Apr 16, 2019
Exela Pharma Sciences, LLC. — Marketing Organization
Dec 13, 2019
Baxalta — Marketing Organization
Dec 13, 2019
Avadel Pharmaceuticals — Marketing Organization
Dec 13, 2019
Takeda — NDA Secondary Org

2020s

Apr 8, 2022
Dr. Reddy's Laboratories — Marketing Organization
Jan 26, 2023
Nivagen Pharmaceuticals Inc. — Marketing Organization
Jan 26, 2023
Hikma — Marketing Organization

Indications

Approved for

Studied for

Mechanism of action

cysteineSupplementation
cysteine supplementation

Approval history

approvedOct 22, 1986

Chemistry & pharmacology

Loading structure…

SMILES

N[C@@H](CS)C(=O)O

Mol. weight: 121.16 g/mol
Lipinski Ro5: Pass
Rule of 3: No
Chirality: Single Stereoisomer
Inorganic: No
Polymer: No
Delivery: Parenteral
Availability: Prescription Only

Oral

Parenteral

Yes

Topical

Sources

Also known as

(2r)-2-amino-3-mercaptopropanoic acid
(2r)-2-amino-3-mercaptopropanoic acid
(2r)-2-amino-3-sulfanylpropanoic acid
(2r)-2-amino-3-sulfanylpropanoic acid
cys
cys
cystein
cystein
cysteine
cysteine
cysteine
cysteine
cysteine
cysteine
cysteine
cysteine
cysteine hcl
cysteine hcl
cysteine hcl
cysteine hydrochloride
cysteine hydrochloride
cysteine hydrochloride
cysteine hydrochloride
cysteine hydrochloride
cysteine hydrochloride
cysteine hydrochloride
e920
e920
e921
e921
free cysteine
free cysteine
l-2-amino-3-mercaptopropionic acid
l-2-amino-3-mercaptopropionic acid
l-cys
l-cys
l-cystein
l-cystein
l-cysteine
l-cysteine
l-cysteine
l-cysteine
l-cysteine
l-cysteine
l-cysteine ethylester hcl
l-cysteine ethylester hcl
l-cysteinemethyl hcl
l-cysteinemethyl hcl
l-zystein
l-zystein
(r)-2-amino-3-mercaptopropanoic acid
(r)-2-amino-3-mercaptopropanoic acid
(r)-cysteine
(r)-cysteine

Clinical trials

NCT ID	Phase	Start date	Sponsor(s)
NCT04701346	N/A	Mar 1, 2021	Charles University, Maastricht University, University of Oslo, University of Oxford
NCT04939792	Early Phase 1 (Phase 1)	Nov 6, 2020	Louisiana State University
NCT03180775	N/A	Jul 1, 2017	Technion University
NCT02462746	Phase 1	Mar 1, 2015	University of Toronto
NCT02050139	Phase 2	Feb 1, 2014	Bio3 Research s.r.l. - Milan Italy, Mario Negri Institute
NCT02524262	Phase 2	Dec 1, 2012	Biohit Oyj, Clinical Trial Consultants AB, University of Helsinki, Uppsala University
NCT00969527	Phase 3	Sep 1, 2009	Catalysis SL
NCT00858897	N/A	Jun 1, 2007	Juvenile Diabetes Research Foundation, Thomas Jefferson University
NCT00254176	Phase 2/Phase 3 (Phase 3)	Sep 1, 2006	University of California, Los Angeles
NCT00253773	N/A	Jan 1, 2005	Emory University, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NCT00253760	N/A	Feb 1, 2004	Emory University, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NCT00004831	N/A	Oct 1, 1996	Food and Drug Administration, St. Luke's-Roosevelt Hospital Center
NCT00004940	Phase 3	May 1, 1996	Harvard University

Showing 13 of 13 trials

Page 1 / 1

Organizations

Research & Development (22)

Organization	Org type	Trials	As lead sponsor	Phases	Earliest year
Emory University	Academic/Hospital	2	0	1	2004
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Government	2	2	1	2004
Bio3 Research s.r.l. - Milan Italy	For profit	1	0	1	2014
Biohit Oyj	For profit	1	0	1	2012
Catalysis SL	For profit	1	1	1	2009
Charles University	Academic/Hospital	1	0	1	2021
Clinical Trial Consultants AB	For profit	1	0	1	2012
Food and Drug Administration	Government	1	1	1	1996
Harvard University	Academic/Hospital	1	1	1	1996
Juvenile Diabetes Research Foundation	Academic/Hospital	1	0	1	2007
Louisiana State University	Academic/Hospital	1	1	1	2020
Maastricht University	Academic/Hospital	1	0	1	2021
Mario Negri Institute	Academic/Hospital	1	1	1	2014
St. Luke's-Roosevelt Hospital Center	Academic/Hospital	1	0	1	1996
Technion University	Academic/Hospital	1	1	1	2017
Thomas Jefferson University	Academic/Hospital	1	1	1	2007
University of California, Los Angeles	Academic/Hospital	1	1	1	2006
University of Helsinki	Academic/Hospital	1	0	1	2012
University of Oslo	Academic/Hospital	1	1	1	2021
University of Oxford	Academic/Hospital	1	0	1	2021

22 organizations

Page 1 / 2

Marketing (10)

Organization	Org type	Relationship	Date
Abbott	For profit	NDA	Oct 22, 1986
Avadel Pharmaceuticals	For profit	MKTG	Dec 13, 2019
Baxalta	For profit	MKTG	Dec 13, 2019
Dr. Reddy's Laboratories	For profit	MKTG	Apr 8, 2022
Exela Pharma Sciences, LLC.	For profit	NDA2	Apr 16, 2019
Exela Pharma Sciences, LLC.	For profit	MKTG	Apr 16, 2019
Hikma	For profit	MKTG	Jan 26, 2023
Hospira	For profit	NDA2	Oct 22, 1986
Nivagen Pharmaceuticals Inc.	For profit	MKTG	Jan 26, 2023
Takeda	For profit	NDA2	Dec 13, 2019