NAC
N-Acetyl Cysteine is a precursor to glutathione — the body's master antioxidant. In the brain, NAC provides potent neuroprotection against oxidative stress and also modulates glutamate signaling through the cystine-glutamate antiporter. It is used clinically for acetaminophen overdose and is studied for OCD, addiction, and neurodegenerative diseases.
Dosage
Standard: 600-1800 mg daily in 1-2 divided doses. Clinical (OCD/addiction): 1200-2400 mg daily. Take on an empty stomach for best absorption. Some practitioners combine with Vitamin C to enhance glutathione recycling.
Dosages shown are for research reference only. Always consult a qualified healthcare provider.
Half-Life
5.6 hours
Administration
Oral (capsules, powder). Take on an empty stomach. Unpleasant sulfur taste in powder form.
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Mechanism of Action
NAC is deacetylated to cysteine, the rate-limiting substrate for glutathione synthesis via gamma-glutamylcysteine synthetase and glutathione synthetase. Glutathione (GSH) is the primary intracellular antioxidant in neurons, neutralizing reactive oxygen species and maintaining redox balance. NAC also activates the cystine-glutamate antiporter (System Xc-, composed of SLC7A11 and SLC3A2 subunits), which exchanges extracellular cystine for intracellular glutamate in a 1:1 ratio. This non-vesicular mechanism modulates extrasynaptic glutamate levels, reducing NMDA receptor overactivation and excitotoxicity. The glutamate-modulating effect explains NAC's promise in OCD (reducing corticostriatal glutamate hyperactivity), addiction (normalizing nucleus accumbens glutamate after drug exposure), and neurodegenerative conditions involving glutamate dysregulation.
Regulatory Status
OTC supplement in most countries. FDA-approved as a prescription drug (Mucomyst) for acetaminophen overdose. Some regulatory uncertainty about supplement status in the US.
Risks & Safety
Common
Nausea, vomiting, diarrhea, foul-smelling breath.
Serious
May interact with blood thinners and nitroglycerin. Concern that antioxidants may reduce efficacy of chemotherapy (theoretical).
Rare
Bronchospasm (in people with asthma), anaphylactic-like reactions.
Compare NAC With
Research Papers
10Published: August 31, 2020
AI Summary
Previous studies have indicated that NAC TFs are key regulators of the plant stress response. However, these studies have been for six years so far and mainly focused on drought and salt stress.
Published: December 22, 2021
AI Summary
In most cases the mechanism of action has remained unclear and untested. The antioxidative and cytoprotective activities of per- and polysulfides may explain many of the effects that have previously been ascribed to NAC or NAC-derived glutathione.
Published: March 25, 2025
AI Summary
NAC can reduce oxidative stress in the retina and has shown potential neuroprotective effects in preclinical models. Initial clinical studies indicate improvements in visual acuity and macular function with NAC therapy, though no structural changes have yet been demonstrated.
Published: December 30, 2003
AI Summary
We discuss the relationship between the structure and function of the NAC family proteins in light of our results and the published data. Our results will aid further functional analysis of NAC family genes.
Published: November 8, 2022
AI Summary
Understanding the mechanism of antioxidants is crucial for interpretation of the results. Because neither NAC nor the fluorescent probes indicated above react directly with hydrogen peroxide, it is critically important to reinterpret the results to advance our understanding of the mechanism of action of NAC and shed additional mechanistic insigh...
Published: May 21, 2025
AI Summary
This review highlights recent advances in the biological functions and signaling pathways of NAC TFs in crops under abiotic stress conditions, such as drought, salinity, and extreme temperatures. It also offers prospects for further exploration of the complex mechanisms by which NAC TFs operate within signaling networks, with the aim of developi...
Published: December 21, 2025
AI Summary
The nascent polypeptide-associated complex (NAC) is a conserved ribosome-bound factor with essential yet incompletely understood roles in protein biogenesis1. Our findings establish NAC as an early-acting, multi-faceted orchestrator of co-translational proteostasis, with distinct mechanisms of action on nascent chains depending on their sequence...
Published: July 30, 2025
AI Summary
The nascent polypeptide-associated complex (NAC) is a conserved ribosome-bound factor with essential yet incompletely understood roles in protein biogenesis. Our findings establish NAC as an early-acting, multifaceted orchestrator of cotranslational proteostasis, with distinct mechanisms of action on nascent chains depending on their sequence fe...
Published: July 12, 2015
AI Summary
Furthermore, studies of the functional rice ortholog, OsNAP, suggest that NAC genes can be targeted to obtain specific changes in lifespan control and nutrient remobilization in crop plants. Thus, NAC genes are promising targets for fine-tuning senescence for increased yield and quality.
Published: March 22, 2014
AI Summary
Plant-specific NAM/ATAF/CUC (NAC) transcription factors (TFs) have recently received considerable attention due to their significant roles in plant development and stress signaling. Recent studies have identified both up-stream regulators of NAC genes and down-stream NAC target genes, outlining regulatory networks associated with NAC-protein int...
Frequently Asked Questions
What is NAC used for?
N-Acetyl Cysteine is a precursor to glutathione — the body's master antioxidant. In the brain, NAC provides potent neuroprotection against oxidative stress and also modulates glutamate signaling through the cystine-glutamate antiporter. It is used clinically for acetaminophen overdose and is studied for OCD, addiction, and neurodegenerative diseases.
What are the side effects of NAC?
Common: Nausea, vomiting, diarrhea, foul-smelling breath. Serious: May interact with blood thinners and nitroglycerin. Concern that antioxidants may reduce efficacy of chemotherapy (theoretical). Rare: Bronchospasm (in people with asthma), anaphylactic-like reactions.
How is NAC administered?
NAC is administered via oral (capsules, powder). take on an empty stomach. unpleasant sulfur taste in powder form..
What is the half-life of NAC?
The half-life of NAC is 5.6 hours.
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