Acetylcysteine

For acute ingestion or from repeated supratherapeutic ingestion (RSI). Sold as Mucomyst, Acetadote, Cetylev. Every FDA application for this active ingredient: 3 branded and 30 generic.

As of Nov 15, 2026, FDA lists 33 applications for Acetylcysteine (sold as Mucomyst, Acetadote, Cetylev), first approved Sep 14, 1963, with 3 new uses approved and 0 published complete response letters.

First approved: Sep 14, 1963
Applications: 33
New uses approved: 3
Complete response letters: 0
Medicare spending, 2025: $5.0M

Medicare Spending

CMS Part D and Part B, 2025, before manufacturer rebates; matched by generic name


Acetylcysteine	Part B	$2.7M	+16%	3,390
Acetylcysteine	Part D	$2.3M	+20%	6,155
Acetadote	Part B	$0K	-42%	131

What Pharmacies Pay

Median price per unit across package codes in CMS's weekly NADAC survey, Nov 11, 2026, before rebates; see every drug's price change

ACETYLCYSTEINE 10% VIAL (NOT FOR INJECTION): $0.966 per MLGeneric · +13% in a year
ACETYLCYSTEINE 20% VIAL (NOT FOR INJECTION): $2.34 per MLGeneric · +77% in a year

Orphan Designations (FDA)

2 designations, 1 approved for the designated use; see all orphan designations

For the intravenous treatment of moderate to severe acetaminophen overdoseCumberland Pharmaceuticals, Inc. · designated Oct 19, 2001 · approved Jan 23, 2004
Intravenous treatment of patients presenting with moderate to severe acetaminophen overdose.Bristol-Myers Squibb Company · designated Aug 13, 1987

Approvals in Japan (PMDA)

PMDA's English list since 2008, matched by ingredient; see all Japanese approvals

Renail, new approvalA drug with a new route of administration indicated for the support of pincer nail correction. · Maruho Co., Ltd. · Mar 27, 2023

Clinical Trials

104 open or ongoing studies name this ingredient as an intervention, including as a comparator; newest first. See all


Assessment of The Potential Therapeutic Effects of Trimetazidine on Aluminium Phosphide-Induced Cardiotoxicity as an Adjuvant Therapy: A Pilot StudyAluminum Phosphide Poisoning · Ain Shams University	Phase 3	Recruiting	Nov 4, 2026
Oral N-Acetylcysteine on Diabetic Macular EdemaDiabetic Macular Edema (DME) · Khadija Ahmed Mhrose Glal	Phase 2	Recruiting	Nov 4, 2026
N-Acetylcysteine for Bipolar and Alcohol Use DisordersBipolar Disorder, Alcohol Use Disorder · Medical University of South Carolina	Phase 2	Not yet recruiting	Nov 3, 2026
FEAST and HOPE: Redox PSC Pilot StudyPrimary Sclerosing Cholangitis (PSC) · Brigham and Women's Hospital	Phase 2	Not yet recruiting	Oct 27, 2026
Combined Metabolic Activator Supplementation in Subjects Diagnosed With GoutGout Disease · ScandiBio Therapeutics AB	Phase 3	Not yet recruiting	Oct 22, 2026
Silymarin Versus N-Acetylcysteine as Protective Effect Against Anti-tuberculosis Drugs Induced Liver Injury.Drug-Induced Acute Liver Injury, Tuberculosis (TB) · Assiut University	Early phase 1	Not yet recruiting	Oct 15, 2026
Study to Evaluate the Effects of Oral Glyceryl Guiacolate (Guaifenesin, GGE) on Sputum Rheology in Subjects With Mucus HypersecretionBronchitis, Bronchitis, Chronic · University of North Carolina, Chapel Hill	Phase 4	Not yet recruiting	Oct 14, 2026
NAC for Hematopoietic Recovery in Low/Intermediate-Risk AML After CR: A Randomized Controlled StudyAcute Myeloid Leukemia, Adult · Peking University People's Hospital	Not applicable	Not yet recruiting	Oct 9, 2026

Applications

NDAs, BLAs and generic ANDAs for this ingredient, oldest first; each opens its full history


Sep 14, 1963	MucomystNDA 13601 · New molecular entity	Apothecon	27	Discontinued
Oct 14, 1986	Mucosil-20ANDA 70576	Dey	23	Discontinued
Oct 14, 1986	Mucosil-10ANDA 70575	Dey	19	Discontinued
Apr 30, 1992	AcetylcysteineANDA 72323	Roxane	5	Discontinued
Apr 30, 1992	AcetylcysteineANDA 72324	Roxane	5	Discontinued
Sep 30, 1992	AcetylcysteineANDA 72622	Roxane	5	Discontinued
Sep 30, 1992	AcetylcysteineANDA 72621	Roxane	5	Discontinued
Aug 30, 1994	AcetylcysteineANDA 74037	Hospira	6	Marketed
Aug 30, 1994	AcetylcysteineANDA 73664	Hospira	6	Marketed
Jul 28, 1995	AcetylcysteineANDA 72489	Am Regent	5	Marketed
Jul 28, 1995	AcetylcysteineANDA 72547	Am Regent	5	Marketed
Jan 23, 2004	AcetadoteNDA 21539 · New dosage form	Apotex	13	Marketed
Nov 20, 2007	AcetylcysteineANDA 71364	Hospira	8	Discontinued
Nov 20, 2007	AcetylcysteineANDA 71365	Hospira	8	Discontinued
Jun 21, 2012	AcetylcysteineANDA 203853	Alvogen	0	Marketed
Nov 7, 2012	AcetylcysteineANDA 200644	Fresenius Kabi USA	1	Marketed
Feb 11, 2014	AcetylcysteineANDA 204674	Alvogen	0	Marketed
Mar 24, 2015	AcetylcysteineANDA 203173	Rising	2	Marketed
Jan 29, 2016	CetylevNDA 207916 · New dosage form	Arbor Pharms LLC	3	Discontinued
Feb 29, 2016	AcetylcysteineANDA 207358	Eugia Pharma	1	Marketed
Oct 31, 2017	AcetylcysteineANDA 91684	Sagent Pharms Inc	2	Marketed
Jul 20, 2018	AcetylcysteineANDA 208166	Zydus Pharms	2	Marketed
Apr 15, 2021	AcetylcysteineANDA 204797	Exela Pharma	0	Discontinued
Feb 3, 2022	AcetylcysteineANDA 213693	Glenmark Pharms	0	Marketed
Feb 23, 2022	AcetylcysteineANDA 215620	Regcon Holdings	0	Marketed
Apr 19, 2023	AcetylcysteineANDA 217182	Onesource Specialty	0	Marketed
Nov 1, 2023	AcetylcysteineANDA 205643	Exela Pharma	0	Discontinued
Jun 7, 2024	AcetylcysteineANDA 218397	Somerset Theraps LLC	0	Marketed
Feb 12, 2025	AcetylcysteineANDA 219194	Somerset Theraps LLC	1	Marketed
Mar 14, 2025	AcetylcysteineANDA 214177	Conba USA	0	Marketed
—	AcetylcysteineANDA 71740	Quad Pharms	0	Discontinued
—	AcetylcysteineANDA 71741	Quad Pharms	0	Discontinued
—	AcetylcysteineANDA 203624	Rising	3	Discontinued

Applications, approvals and products come from FDA's Drugs@FDA data files, refreshed weekly, grouped by active ingredient as FDA spells it. Complete response letters are FDA's published letters. Medicare spending is CMS's Part D and Part B dashboard, matched to this ingredient by generic name; shortages are FDA's shortage list, matched by application number; clinical trials are ClinicalTrials.gov studies naming the ingredient as an intervention, refreshed daily; safety programs are FDA's REMS list, matched by application number or, for shared programs, by ingredient. Drugs@FDA