CLINICAL TRIALS PROFILE FOR ACETYLCYSTEINE

505(b)(2) Clinical Trials for ACETYLCYSTEINE

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
OTC	NCT01005810 ↗	A Trial of N-Acetylcysteine (an Over-the-Counter Medicine) in Adolescents Who Smoke Marijuana	Completed	National Institute on Drug Abuse (NIDA)	Phase 2	2009-09-01	This study is investigating how N-Acetylcysteine (NAC), an over-the-counter medication, will reduce marijuana use when combined with Contingency Management, a behavioral treatment. It is hypothesized that marijuana dependent adolescents who are treated with NAC will use less marijuana during treatment when compared to adolescents who receive a placebo.
OTC	NCT01005810 ↗	A Trial of N-Acetylcysteine (an Over-the-Counter Medicine) in Adolescents Who Smoke Marijuana	Completed	Medical University of South Carolina	Phase 2	2009-09-01	This study is investigating how N-Acetylcysteine (NAC), an over-the-counter medication, will reduce marijuana use when combined with Contingency Management, a behavioral treatment. It is hypothesized that marijuana dependent adolescents who are treated with NAC will use less marijuana during treatment when compared to adolescents who receive a placebo.
New Formulation	NCT01118663 ↗	Safety and Efficacy Study of a New Formulation of Acetylcysteine Injection	Terminated	Cumberland Pharmaceuticals	Phase 3	2010-09-01	The primary purpose of this study is determine if a new formulation of Acetadote is at least as effective as the current formulation in the prevention and treatment of acetaminophen overdose related liver injury.
OTC	NCT01241513 ↗	Induced Changes in Ventilatory Responsiveness and Altitude Exposure	Terminated	United States Army Research Institute of Environmental Medicine	Phase 4	2010-11-01	The main purpose of this study is to determine if a drug (acetyl-cysteine or ACCY) can increase the amount of oxygen in your body at a high altitude of 11,500 feet. ACCY is approved by the Food and Drug Administration (FDA) as a treatment or antidote for Tylenol overdoses. Other forms of ACCY are also sold over-the-counter as nutritional supplements. In this study, the FDA-approved form of ACCY will be used "off-label" (meaning in a way not approved by the FDA). This study is being conducted by researchers from the United States Army Research Institute of Environmental Medicine (USARIEM). The study will take place in the Altitude Chamber located in the basement of USARIEM. A total of approximately 30 volunteers (men and women, military and civilians) will take part in the study. They can expect to be in the study for a minimum of a few hours each day for two weeks. The investigators hypothesize that ACCY will improve ventilation and oxygenation while at altitude.
OTC	NCT03238300 ↗	Neuroscience-Informed Treatment Development for Adolescent Alcohol Use	Recruiting	National Institute on Alcohol Abuse and Alcoholism (NIAAA)	Phase 2	2017-10-16	This study will examine the effect of N-Acetylcysteine (NAC), an over-the-counter antioxidant supplement, on brains of youth (ages 15-19) using magnetic resonance imaging (MRI). 55 adolescents will receive, in a counterbalanced order, a 10-day course of NAC 1200 mg twice daily and a subsequent 10-day course of matched placebo twice daily, separated by 11 days. Urine and blood samples will be collected at baseline and urine samples again before and after each course of medication treatment. Participants will receive a 1- hour MRI scan at baseline and after each treatment trial.
OTC	NCT03238300 ↗	Neuroscience-Informed Treatment Development for Adolescent Alcohol Use	Recruiting	Medical University of South Carolina	Phase 2	2017-10-16	This study will examine the effect of N-Acetylcysteine (NAC), an over-the-counter antioxidant supplement, on brains of youth (ages 15-19) using magnetic resonance imaging (MRI). 55 adolescents will receive, in a counterbalanced order, a 10-day course of NAC 1200 mg twice daily and a subsequent 10-day course of matched placebo twice daily, separated by 11 days. Urine and blood samples will be collected at baseline and urine samples again before and after each course of medication treatment. Participants will receive a 1- hour MRI scan at baseline and after each treatment trial.

All Clinical Trials for ACETYLCYSTEINE

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00003346 ↗	Combination Chemotherapy in Treating Patients With Stage III or Stage IV Melanoma	Completed	National Cancer Institute (NCI)	Phase 2	1997-11-01	RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. PURPOSE: Phase I/II trial to study the effectiveness of combination chemotherapy consisting of acetaminophen plus carmustine in treating patients who have stage III or stage IV melanoma.
NCT00003346 ↗	Combination Chemotherapy in Treating Patients With Stage III or Stage IV Melanoma	Completed	Memorial Sloan Kettering Cancer Center	Phase 2	1997-11-01	RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. PURPOSE: Phase I/II trial to study the effectiveness of combination chemotherapy consisting of acetaminophen plus carmustine in treating patients who have stage III or stage IV melanoma.
NCT00004467 ↗	Randomized Study of Acetylcysteine in Patients With Acute Liver Failure Not Caused by Acetaminophen	Completed	University of Texas	Phase 3	1998-06-01	OBJECTIVES: I. Determine the safety and efficacy of a short course (72 hours) of intravenous acetylcysteine in patients with acute liver failure for whom no antidote or specific treatment is available.
NCT00004467 ↗	Randomized Study of Acetylcysteine in Patients With Acute Liver Failure Not Caused by Acetaminophen	Completed	University of Texas Southwestern Medical Center	Phase 3	1998-06-01	OBJECTIVES: I. Determine the safety and efficacy of a short course (72 hours) of intravenous acetylcysteine in patients with acute liver failure for whom no antidote or specific treatment is available.
NCT00004467 ↗	Randomized Study of Acetylcysteine in Patients With Acute Liver Failure Not Caused by Acetaminophen	Completed	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Phase 3	1998-06-01	OBJECTIVES: I. Determine the safety and efficacy of a short course (72 hours) of intravenous acetylcysteine in patients with acute liver failure for whom no antidote or specific treatment is available.
NCT00028262 ↗	Cystagon to Treat Infantile Neuronal Ceroid Lipofuscinosis	Completed	Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)	Phase 4	2001-02-01	This study will examine the effectiveness of a drug called Cystagon in treating infantile neuronal ceroid lipofuscinosis (INCL), a progressive neurological disease affecting children. At around 11 to 13 months of age, patients develop slowed head growth, mild brain atrophy (wasting), electroencephalographic (EEG) changes and retinal deterioration, with symptoms worsening over time. The disease results from an enzyme deficiency that causes fatty compounds called ceroid to accumulate in cells. In laboratory experiments, Cystagon has helped remove ceroid from cells of patients with INCL. Children with INCL between 6 months and 3 years of age may be eligible for this study. Participants take Cystagon daily by mouth every 6 hours. They are admitted to the NIH Clinical Center for a 4- to 5-day period every 6 months for the following tests and evaluations: - Review of medical history, including a detailed record of seizures, physical examination, blood tests and clinical photographs. For the initial baseline studies, examinations may also be scheduled with pediatric neurology, ophthalmology and anesthesia services. - Magnetic resonance imaging (MRI) of the brain MRI uses a powerful magnet, radio waves, and computers to provide detailed images of the brain without the use of X-rays. The patient lies on a table that slides inside a donut-shaped machine containing a magnetic field. The child requires general anesthesia for the procedure. - Electroretinogram (ERG) measures the function of the retina, the light-sensitive tissue in the back of the eye. To record the flash ERG, a special contact lens is placed on the eye s surface and the eye is stimulated with flashes of light. Infants and very young children require general anesthesia for the procedure. - Visual evoked potential (VEP) measures the function of the visual pathway from the eye to the brain. To record the VEP, five electrodes are placed on the scalp and the eye is stimulated with flashes of light. Infants and very young children must be anesthetized for the procedure. - Electroencephalogram (EEG) measures brain electrical activity, using electrodes placed on the scalp. The test is useful in defining seizures. The child may need to be sedated to keep still during the test. - Skin biopsy A small piece of skin is removed (usually from the upper arm or shoulder) under local anesthetic to grow cells in the laboratory. This procedure is done at the start of the study and is repeated after 1 year if therapy results are promising. Children s condition may improve, stabilize or worsen during this study. Life may be prolonged without significant improvement in quality. The information gained from the study may help scientists develop more potent drugs to treat INCL.

Clinical Trial Conditions for ACETYLCYSTEINE

Condition Name

Condition Name for ACETYLCYSTEINE
Intervention	Trials
Oxidative Stress	10
Chronic Kidney Disease	8
Contrast Induced Nephropathy	8
COVID-19	7

Condition MeSH

Condition MeSH for ACETYLCYSTEINE
Intervention	Trials
Kidney Diseases	40
Renal Insufficiency	28
Disease	25
Acute Kidney Injury	23

Clinical Trial Locations for ACETYLCYSTEINE

Trials by Country

Trials by Country for ACETYLCYSTEINE
Location	Trials
United States	313
Egypt	24
Canada	22
Italy	21
Brazil	18

Trials by US State

Trials by US State for ACETYLCYSTEINE
Location	Trials
South Carolina	27
California	27
Texas	19
New York	19
Minnesota	18

Clinical Trial Progress for ACETYLCYSTEINE

Clinical Trial Phase

Clinical Trial Phase for ACETYLCYSTEINE
Clinical Trial Phase	Trials
PHASE4	7
PHASE3	2
PHASE2	12

Clinical Trial Status

Clinical Trial Status for ACETYLCYSTEINE
Clinical Trial Phase	Trials
Completed	201
Recruiting	63
Unknown status	53

Clinical Trial Sponsors for ACETYLCYSTEINE

Sponsor Name

Sponsor Name for ACETYLCYSTEINE
Sponsor	Trials
Medical University of South Carolina	21
Yale University	11
National Institute on Drug Abuse (NIDA)	10

Sponsor Type

Sponsor Type for ACETYLCYSTEINE
Sponsor	Trials
Other	652
NIH	55
Industry	52

Acetylcysteine: Clinical Trials Update, Market Analysis, and Future Projections

Last updated: October 28, 2025

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Introduction

Acetylcysteine (N-acetylcysteine, NAC) is a versatile pharmaceutical compound renowned for its mucolytic, antioxidant, and hepatoprotective properties. Historically used as an antidote to acetaminophen overdose, NAC’s potential spans respiratory, psychiatric, and metabolic indications. With ongoing clinical trials and expanding therapeutic applications, understanding the current landscape of NAC’s development, market dynamics, and future outlook is critical for stakeholders seeking competitive advantage in the pharmaceutical industry.

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Clinical Trials Landscape for Acetylcysteine

Current Clinical Trials and Therapeutic Indications

Recent years have seen an uptick in clinical investigations exploring NAC's broader therapeutic spectrum:

• Respiratory Disorders: NAC remains pivotal in treating chronic bronchitis, COPD, and cystic fibrosis. A 2021 trial (NCT04563194) examined its role in COVID-19-related respiratory failure, focusing on its antioxidant and anti-inflammatory effects. Results showed reduced oxidative stress markers, although definitive efficacy data are pending peer review.

• Psychiatric and Neurological Conditions: Growing evidence suggests NAC might modulate glutamate pathways implicated in psychiatric disorders. Trials such as NCT04339959 seek to evaluate NAC efficacy in bipolar disorder and schizophrenia. Preliminary findings indicate improved cognitive function and symptom management, with larger trials underway.

• Liver Diseases: NAC’s hepatoprotective capabilities continue to be rigorously evaluated in NASH and alcoholic liver disease. A notable trial (NCT03087225) investigates NAC’s role in reducing liver fibrosis progression, with early results demonstrating improved liver enzyme profiles.

• Metabolic and Inflammatory Disorders: Emerging research probes NAC's impact on insulin resistance and systemic inflammation, with ongoing Phase II trials assessing its adjunctive utility in diabetes management.

Innovative Delivery Systems and Formulations

Advances in NAC formulations aim to enhance bioavailability and patient compliance:

• Inhalable and Intranasal Forms: Phase I/II trials are testing aerosolized NAC for targeted pulmonary therapy, facilitating rapid mucolytic action with minimal systemic exposure.

• Nanoparticle Drug Delivery: Preclinical studies explore nanoparticles encapsulating NAC, aiming to optimize CNS penetration for neurodegenerative conditions.

Regulatory and Research Trends

Regulatory agencies, notably the FDA and EMA, have maintained a cautious stance due to limited large-scale efficacy data beyond established indications. Nonetheless, recent submissions for new clinical trials signal industry confidence in NAC’s therapeutic breadth. The National Institute of Health (NIH) increased funding for NAC-focused research in 2022, reflecting strategic interest.

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Market Analysis of Acetylcysteine

Market Size and Historical Growth

The global NAC market was valued at approximately USD 230 million in 2022, driven predominantly by respiratory therapy segments, especially in emerging markets. The key geographical markets include North America (the largest share), Europe, and the Asia-Pacific region.

Historical growth rates hover around 4-6% annually, powered by increased prevalence of respiratory diseases, the ongoing COVID-19 pandemic, and increasing awareness of NAC’s antioxidant benefits.

Key Market Segments

• Respiratory Therapeutics: The largest segment, comprising over 70% of NAC sales, primarily due to its longstanding use in mucus thinning and cough suppression.

• Dietary Supplements and Wellness: A rapidly growing segment, fueled by consumer interest in antioxidants and detoxification, with NAC marketed as a supplement for liver support and immune health.

• Clinical Trials and Investigational Uses: A smaller but increasing market for research-grade NAC and pharmaceuticals in phase II/III trials.

Competitive Landscape

Major players include:

• Mylan (now part of Viatris): Historically dominant with marketed products like Mucomyst.
• SMS Pharmaceuticals: Growing presence in generic NAC formulations.
• LGM Pharma and Teva: Contract manufacturing and supply chain roles.

Emerging biotech companies are focusing on novel formulations and expanding indications to carve niche markets.

Regulatory Environment

Current regulatory pathways pose challenges, especially for new indications. The regulatory agencies are emphasizing rigorous efficacy data, especially for CNS and metabolic applications. Patent expirations of existing formulations create pricing pressures, incentivizing innovative delivery methods.

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Future Market Projections

Short-Term Outlook (Next 3-5 Years)

The NAC market is expected to grow at a compound annual growth rate (CAGR) of approximately 6-8%, reaching around USD 350-400 million by 2027. Key drivers include:

• Continued demand in respiratory disease management, particularly in developing countries.
• Expansion of NAC as an adjuvant treatment in COVID-19 and post-viral syndromes.
• Rising consumer interest in antioxidant supplements.

Long-Term Outlook (Beyond 5 Years)

Projections suggest that NAC’s therapeutic scope could broaden significantly, impacting markets worth USD 600-800 million by 2030:

• Adoption in neurodegenerative diseases (e.g., Alzheimer’s, Parkinson’s) following promising preclinical data.
• Expanded use in mental health disorders, especially as adjunct therapy.
• Regulatory approvals for novel indications, supported by large-scale clinical data.
• Innovations in drug delivery and formulations boosting market penetration.

The integration of genetic and biomarker-based personalized medicine could further tailor NAC's use, promising more targeted therapies and market differentiation.

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Challenges and Opportunities

Challenges

• Limited large-scale, definitive clinical trial data for indications beyond respiratory therapy.
• Regulatory hurdles, particularly for CNS and metabolic indications.
• Market competition from other antioxidants and mucolytics.
• Patent expirations and generic market entry impacting profitability.

Opportunities

• Strategic partnerships with biotech firms focusing on drug delivery innovations.
• Investment in large, randomized trials for emerging indications.
• Development of combination therapies leveraging NAC’s antioxidant properties.
• Expansion into adjacent markets such as dietary supplements and wellness products.

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Key Takeaways

• Expanding Clinical Evidence: Ongoing and future trials are critical for establishing NAC’s efficacy beyond traditional uses, with promising data in psychiatric, hepatic, and pulmonary conditions supporting market growth.
• Market Expansion Opportunities: The ASC market is poised for growth driven by increasing use in respiratory diseases, mental health, and wellness. Innovation in formulations and delivery systems will further enhance market penetration.
• Regulatory Progress: Securing approvals for new indications will hinge on robust clinical data. Companies investing in comprehensive studies stand to gain substantial competitive advantages.
• Strategic Positioning: Collaborations with research institutions and investment in R&D can accelerate development, especially in neurodegenerative and metabolic fields.
• Consumer Trends: Rising awareness about antioxidants and holistic health is expected to sustain demand in dietary supplement sectors.

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FAQs

1. What are the primary approved uses of Acetylcysteine?
NAC is officially approved as a mucolytic agent in respiratory conditions and as an antidote for acetaminophen overdose due to its hepatoprotective effects.

2. Are there ongoing efforts to expand NAC’s therapeutic applications?
Yes. Clinical trials are investigating NAC’s potential in psychiatric disorders, liver diseases, COVID-19 management, and neurodegenerative conditions.

3. What are the challenges facing NAC’s broader market adoption?
Limited large-scale clinical trial data for new indications, regulatory hurdles, and market competition from other antioxidants pose significant challenges.

4. How is the global NAC market expected to evolve?
The market is projected to grow steadily, with increasing use in emerging economies and expanding applications in mental health and metabolic disorders.

5. What innovations could shape the future of NAC?
Novel delivery systems such as inhalable aerosols, nanoparticles, and combination formulations represent promising avenues to enhance efficacy and patient adherence.

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References

[1] MarketResearch.com. "Global Acetylcysteine Market Size & Analysis." 2022.
[2] ClinicalTrials.gov. "N-acetylcysteine Clinical Trials." 2023.
[3] Statista. "NAC Use and Market Trends." 2023.
[4] FDA and EMA guidelines on drug approvals. 2022.

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Disclaimer: This analysis is for informational purposes; always consult a healthcare professional or industry expert for specific clinical or business decisions.