When I talk about taking care of our health with real food, I am often asked: “And what do you think about supplements?” Unfortunately, the food we have today is not the same as what our grandparents ate. Our foods no longer have the same nutrient density, mainly because we have damaged the soil where we grow them and we live in an environment loaded with toxins. So, no matter how organic we eat and how hard we try to live as toxin-free as possible, many times we need a little help from supplements. And, as with everything, it is very important to know which supplements to choose: their quality is just as important as the quality of the food we put on our plate.

One of the supplements I like the most is NAC.

What is NAC?
N-acetylcysteine (NAC) is a stable form of the amino acid cysteine. What is interesting about NAC is that in the body it turns into cysteine, and cysteine is the main raw material needed to produce glutathione, one of the most important antioxidants we have.

Glutathione is like an internal cleaning and protection system: it helps neutralize free radicals, supports liver detoxification processes, protects tissues (including the lungs), and takes part in the proper function of the immune system. That is why it is sometimes called the “master antioxidant.”

NAC is not a new trend: conventional medicine has used it for decades as the standard treatment for acetaminophen (paracetamol) poisoning (because it restores glutathione in the liver) and as a mucolytic, to make respiratory secretions more fluid. That already tells us a lot: it is not something improvised from social media; it is a known, studied molecule with clear clinical applications.

What does the science show us?

In recent years, reviews and trials have been published that confirm several interesting things about NAC:

1. Powerful antioxidant support
   By increasing glutathione levels, NAC helps reduce oxidative stress, a factor involved in chronic inflammation, cellular aging, and immune dysfunction.
2. A more protected respiratory system
   NAC has mucolytic (helps dissolve mucus), antioxidant, anti-infective, and anti-inflammatory properties. This makes it useful for multiple respiratory conditions, from chronic bronchitis to asthma. During winter, when we are more exposed to respiratory viruses, this support can be especially valuable.
3. Immune support during cold season
   One of the most fascinating studies showed that taking NAC during winter significantly reduced flu-like episodes, especially in high-risk older adults. In this study, only 25% of people infected with the virus who were taking NAC developed symptoms, compared to 79% in the placebo group. In other words, even if you get infected, NAC can help your body handle the infection without developing the full-blown illness.
4. Liver support
   In addition to acetaminophen poisoning, it has been studied as a liver protector and in situations of high oxidative stress, with interesting results in certain contexts, always under medical supervision.
5. Additional emerging benefits
   Recent research also suggests that NAC may be useful in:

• Psychiatric and addiction-related conditions
• Chronic cognitive disorders
• Neurological and neurodegenerative diseases
• Management of COVID-19 (although more research is needed)

How does NAC fit into the winter months?

In summary: we have a molecule with a solid scientific basis as an antioxidant, mucolytic, and support in situations of oxidative stress. This makes it especially interesting when we think about cold months, less sun, more viruses circulating, and an immune system with more work to do to defend us from aggressors.

It is not “I take NAC and forget about everything else.” It is: I take care of my body with real food and a healthy lifestyle, and I also incorporate tools/supplements that complement this.

How and when to take it?

DOSAGE: Typical doses in clinical studies range from 600 mg to 1,200 mg per day. In the flu study mentioned, 600 mg twice a day was used for 6 months. It is important to follow the recommendations of the manufacturer or your health professional.

TIMING: Ideally, it is best taken on an empty stomach for better absorption. However, if it causes stomach discomfort, you can take it with food without any problem.

WHEN TO START: Do not wait until you are sick. Ideally, start taking NAC BEFORE cold season begins (September–November) as prevention. This way, your body already has optimized glutathione reserves when it needs them the most.

Synergy with other nutrients

NAC works even better when combined with:

• Vitamin C: Boosts glutathione production and works synergistically as an antioxidant.
• Selenium: An essential mineral needed for glutathione enzymes.
• Vitamin E: Works together with NAC as a complementary antioxidant.

Consider taking these nutrients along with your NAC to maximize its benefits.

Safety considerations

NAC is generally very safe and well tolerated. However:

• It may interact with nitroglycerin.
• If you are pregnant, breastfeeding, or taking medication, consult your doctor before starting.
• Some people may experience mild digestive discomfort at the beginning.

My recommendation

First, if your diet is full of sugar, ultra-processed foods, and very little sleep, NAC is not going to perform magic. First we put our kitchen in order (literally and figuratively).

Second, choose a high-quality NAC, and for that I recommend the brand Pure Encapsulations, which is the one I use at home. It is a brand that meets strict purity standards, is free from common allergens and unnecessary additives, and has third-party certifications that verify its quality and potency.

The idea I am left with (and the one I want you to keep)

Our body knows how to defend, heal, and repair itself if we give it the right nutrients. Winter does not have to be synonymous with constant colds and days lost in bed.

As I always tell you: real food comes first—real, homemade food made with organic ingredients, good quality fats, good quality proteins, rest, light, calm. On that foundation, NAC can be a valuable, science-backed tool to support our glutathione levels, care for our airways, and intelligently strengthen our defenses in those months when we feel like “everyone is sick.”

It is not a trend. It is not a magic solution. It is science used well, added to what truly matters: real food made with love, every day.