NAC (N-Acetyl Cysteine)

NAC (N-Acetyl Cysteine) is the molecule emergency rooms use to save lives from acetaminophen overdose — which tells you something interesting about what it does inside a healthy liver every day. As a direct precursor to glutathione, the body's master antioxidant, NAC replenishes cellular defenses that stress, toxins, and aging steadily erode. A 2020 meta-analysis of 12 RCTs found NAC significantly reduced malondialdehyde, a key marker of oxidative stress, across a range of doses from 400–2000 mg per day. Beyond the liver, NAC modulates glutamate homeostasis in the brain, a mechanism that has made it a subject of serious psychiatric research — with RCTs showing improvements in depression and anxiety scores in patients with mood disorders and substance use conditions. People dealing with chronic oxidative load, respiratory issues, or mood dysregulation alongside high oxidative stress may find NAC particularly relevant. Those on nitroglycerin or blood thinners should flag the interaction with their doctor, and people with asthma or GI ulcers should approach with caution. One of the few supplements that pulls double duty across liver health and brain chemistry — with the hospital-ward credibility to back it up.

Also known as: N-Acetyl Cysteine, N-Acetyl-L-Cysteine