I am often asked for advice on must-have supplements and typically recommend a multi, a probiotic, and fish oil. But there’s one multitasker in particular that has such far-reaching benefits that nearly everyone can benefit from using it. It’s N-Acetyl Cysteine (NAC).
N-Acetyl Cysteine is a pretty amazing amino acid. It can protect your heart, lungs, liver, kidneys, and boost immune health, and it has a wide range of clinical applications. I use N-Acetyl Cysteine (NAC) frequently as part of my gut healing protocols and for its amazing liver detox and protective benefits. I personally have been taking it on and off as needed and haven’t been sick in two years.
What is N-Acetyl Cysteine?
NAC is technically the supplement form of the amino acid l-cysteine, a sulfur-containing amino that is considered “semi-essential.” That means your body can typically produce cysteine from other amino acids, namely methionine and serine, but it becomes essential (meaning you must get it from your diet) when the dietary intake of methionine and serine is low. The best sources of amino acids are animal proteins.
NAC is most widely known and used in hospitals ERs as the specific antidote for acetaminophen overdose. This is mainly because NAC is a precursor to glutathione, your body’s master antioxidant that is powerfully liver protective. Glutathione stores are dramatically depleted in cases of acetaminophen toxicity and can be depleted over time by using NSAIDs (advil, tylenol, aspirin) and alcohol regularly. Sulfur-containing amino acids and vegetables, such as the cruciferous, are particularly good for building glutathione and for liver detox support.
Glutathione reduces oxidative stress from free radicals, encourages longevity, reduces cell damage in alcoholic and nonalcoholic fatty liver disease, and supports mitochondrial function, which means more energy for you. Your body uses NAC to make glutathione.
N-Acetyl Cysteine Benefits
- Boosts glutathione production. You might be wondering, why not just take a glutathione supplement if I want the master antioxidant benefits? NAC is apparently easier to absorb and more bioavailable than taking a glutathione supplement. That means you may benefit more from taking NAC so your body can then convert it to glutathione and replenish glutathione stores that are depleted with age, poor diet, alcohol, stress, infections, and exposure to toxins. Glutathione has many of the same benefits as NAC and is a powerful antioxidant present in every cell of your body. It’s especially useful for liver problems and protecting the liver.
- Reduces inflammation and oxidative damage (read: keeps you looking and feeling young!)
- Prevents liver damage and protects the liver: improves detox, protects the liver from alcohol and environmental toxins. Also kidney protective. (source)
- COPD: may improve the inflammation that occurs with chronic obstructive pulmonary disease (COPD) (source). Improves lung function.
- Improves respiratory conditions like bronchitis, cystic fibrosis, asthma and pulmonary fibrosis, and even breathing issues that result from sinus congestion or viruses. (source)
- Hashimoto’s thyroiditis: may lower antibodies and offer needed antioxidant and anti-inflammatory support for those with Hashimoto’s and other autoimmune conditions. (source)
- Useful for gut protocols: may act as a biofilm buster (though I believe other formulas work better) to make parasite and yeast protocols more effective.
- Boosts immune health and can be effective in treating colds and flu.
- Brain health: NAC’s high antioxidant action makes it brain protective against Parkinson’s and Alzheimer’s and may improve dopamine function. (source)
- Stabilize blood sugar and insulin levels: improves glucose tolerance and insulin resistance (source)
- PCOS & fertility: polycystic ovarian syndrome is exacerbated (caused?) by insulin resistance, and NAC helps with insulin sensitivity. But it may also encourage ovulation and fertility, improving PCOS symptoms and fertility (in those with PCOS and without). (source)
- May be effective in treating certain psychiatric disorders and addictions. (source)
Who Should Use N-Acetyl Cysteine
If you want to improve lung function, fertility, blood glucose and insulin, boost immune health, support liver detox, or if you have PCOS, NAC is for you. I recommend it to anyone who drinks alcohol regularly or takes NSAIDs (advil, tylenol, etc) on a regular basis. It’s excellent for fatty liver disease or any liver condition. If you have liver problems or elevated liver enzymes, I recommend this formula that contains NAC along with other liver protective nutrients.
NAC is also great during the colder winter months when you want to protect immune health and guard against cold and flu. Take it during the holidays if you are drinking more alcohol or eating more sugary treats.
Aside from the above benefits, I use NAC prior to having my clients do anti-microbial gut healing protocols because it may break down biofilms that hide and protect parasites and yeast in the gut. I recommend using NAC 2 weeks prior to an herbal protocol (such as a candida cleanse), then you can continue to use it during the protocol for additional biofilm and liver support.
How to Use N-Acetyl Cysteine
NAC is very safe, well-tolerated, inexpensive, and has few, if any, side effects. At high doses it may nausea, vomiting, diarrhea and constipation. Use caution if you are taking nitroglycerin and related medications because NAC may act as an additional vasodilator.
Try and take NAC ideally 30 minutes before or 2 hours after meals so it doesn’t compete with protein for absorption. I use this NAC and recommend 2 daily as a basic dose (1800mg) for biofilm busting, liver detox support, if you have to take NSAIDs for an injury or ongoing situation, or for addressing any of the above conditions. You can cut down to 1 if you feel any adverse effects. I often recommend you take 2 before bed at night because this is often a couple hours after the last meal, and your liver and immune systems are most active at night.
You can take NAC long term, but no need to take it at higher doses long term. You could take 600-900mg/day for ongoing use, especially if you are a regular alcohol drinker or you breathe in toxic fumes regularly (say, you’re a painter, mechanic, work in a hair salon, etc). I’ve seen recommendations for safe doses up to 3,400mg for acute situations like exposure to toxins, fumes, or even smoke inhalation (remember, it’s very lung protective).
You can also find NAC in formulas for liver support (like this supplement I love, take 4 daily) or a liver cleanse.
NAC is a wonderful health-promoting supplement that’s a good one to have in your tool kit to use as needed.
Mary Vance is a Certified Nutrition Consultant and author specializing in digestive health. She combines a science-based approach with natural therapies to rebalance the body. In addition to her 1:1 coaching, she offers courses to help you heal your gut and improve your health. Mary lives in San Francisco and Lake Tahoe in Northern California. Read more about her coaching practice here and her background here.