Oral N‑acetylcysteine treatment for retinitis pigmentosa

NAC Attack, a phase-3, multicenter, randomized, placebo-controlled trial in patients with retinitis pigmentosa

NIH-funded research Johns Hopkins University · NIH-11179132

Adults with retinitis pigmentosa will take oral N‑acetylcysteine or a placebo to see whether it slows vision loss.

Quick facts

Grant typeNIH-funded research
Study typeNIH-funded research
Funding institutionJohns Hopkins University NIH-funded
Lab location1 site (Baltimore, United States)
Project IDNIH-11179132 on NIH RePORTER

What this research studies

You would be randomly assigned to take oral N‑acetylcysteine (1800 mg twice daily) or a placebo in a double‑masked way, with more people receiving the active pill than placebo (2:1). The trial runs at multiple clinical sites and follows participants for about 45 months with regular eye exams and testing. Johns Hopkins serves as the coordinating center to manage sites, data, and quality assurance. The goal is to track changes in vision and retinal health over time to determine whether the medicine can slow degeneration.

Who could benefit from this research

Good fit: Adults with a confirmed diagnosis of retinitis pigmentosa who meet the study's eligibility criteria and can take oral medication and attend regular visits are the intended participants.

Not a fit: People without retinitis pigmentosa, those with very advanced end‑stage retinal loss, or anyone with medical reasons not to take N‑acetylcysteine are unlikely to benefit from joining.

Why it matters

Potential benefit: If effective, the treatment could slow or prevent further vision loss in people with retinitis pigmentosa.

How similar studies have performed: Smaller clinical studies and laboratory research have suggested NAC may protect photoreceptors, but this larger phase‑3 trial is designed to provide definitive evidence.

Where this research is happening

Baltimore, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.