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Practical info for the smarter drinker

Differences between Cysteine and N-Acetyl Cysteine (NAC)

Alcohol consumption is all about chemistry – once you get past all the fun and flavor, that is.

Most of the time we focus on the outward manifestations of these chemical reactions, because they can be pretty amusing, but there’s a lot of other action going on at the cellular level that often gets ignored.

Cysteine is a “non-essential” amino acid, which is just a confusing way of saying the human body can make it on its own. It’s definitely essential, though, because a metabolite contained in cysteine called N-acetyl cysteine (NAC) is what helps the liver metabolize acetaldehyde.

This is super important because acetaldehyde is no more than a fancy word for poison. It is toxic and it will kill you. It’s more toxic than alcohol itself and is a byproduct of alcohol metabolism. Incidentally, the stuff also occurs in nature and we absorb it every day, which is why we need lots of cysteine and its metabolite, NAC.

The danger of acetaldehyde can’t be overstated. The stuff can totally give you cancer and recent studies have shown that heavy drinkers are far more susceptible to acetaldehyde-related cancer than those who simply absorb it in the environment. Why? Because heavy drinkers are getting much higher doses since they’re basically adding the amount they get from booze to their environmental exposure.

So, even though cysteine may be “non-essential,” making sure you have some on reserve is never a bad idea.

N-Acetyl Cysteine Acetaldehyde




Legal Stuff: We should remind everyone that our blog entries are for your information only and are not intended as medical advice. If you’re going to drink, do it legally and responsibly; don’t be stupid =).


  1. Reply Mark Jun 27, 2016 9:11 am

    With all due respect, an important distinction must be made. NAC is metabolized to cysteine and then GSH. You have it reversed. NAC is not a metabolite of cysteine.

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