Should I Take a NAC Supplement?

A brief look into a trendy amino acid

Published in

Elemental

4 min readOct 25, 2019

A variety of different pills and supplements are laid out in a grid against a white backdrop. — Photo: Image Source/Getty

People take supplements for all sorts of reasons — omega-3s for heart health, calcium for strong bones, vitamin B12 for more energy. But rarely is there one supplement that claims to heal seemingly every ailment, from asthma to liver disease. Yet NAC, short for N-acetyl cysteine, is that kind of pill. Or so its fans like to claim.

On Reddit, users say NAC helps them combat anxiety, asthma, insomnia, and other conditions, while some bodybuilders claim it helps combat muscle fatigue. Research suggests NAC can help prevent cognitive decline and even potentially curb aging.

What’s the truth? Here’s the lowdown on one of the trendier supplements in the grocery aisle.

What is NAC?

NAC is the supplemental form of cysteine, which is an amino acid. Specifically, cysteine is what’s known as a “semi-essential” amino acid, meaning the body can produce it on its own, absorb it from diets high in protein (think poultry and beef), or get it through a NAC supplement.

NAC isn’t a vitamin or a mineral, and because the body makes it on its own, there’s no recommended daily allowance. However, a “therapeutic dosage” of NAC (meaning the amount that’s expected to have benefits) is considered to be no more than 3 grams per day. Though it’s widely available as a pill, NAC can also be taken intravenously, aerosolized, or in liquid form.

What does it do?

Plenty of health products promise to “detoxify” the body, but NAC actually does it, explains Angela Grassi, a registered dietitian nutritionist. NAC, she says, produces a powerful antioxidant called glutathione, which removes harmful free radicals — molecules that cause cell, tissue, and DNA damage. When too many free radicals accumulate in the body, something called oxidative stress occurs, which is often a precursor to inflammation and even cancer. In hospitals, NAC is given intravenously to treat people with acetaminophen overdoses. Its ability to rid the body of free radicals and inflammation is likely one of the reasons why it seems to benefit so many different conditions, including symptoms related to aging.