NAC, aka N-Acetyl cysteine, is a small protein that acts as a liver protector [1]. In medical terms, it’s a precursor to glutathione — one extremely important  antioxidant that helps your liver to «clean up» of all the toxins. 

What Does NAC Do to Your Body

It’s much easier to explain with an example. Here’s how NaC works and why you need it when you take oral anabolic steroids, in 5 steps: 

  1. When you take ANYTHING oral, it goes through your liver. Steroids like Winstrol, Dianabol, or Anavar go there as well;
  2. Naturally, the molecules of these steroids are too weak to bypass your liver. It would just destroy them in no time, if they had no 17-alpha-alkylation: a molecular modification that doesn’t let your liver filter them out;
  3. Liver still sees oral steroids as toxins, though, so it keeps trying to destroy them. Since steroids are present in the liver for a longer period than the liver is used to, and since it wastes a lot of liver cells trying to destroy them, the result is not good for you: your liver gets damaged [2];

Luckily, the liver is capable of self-restoration, so it can literally regenerate after a short and mild oral cycle. It’s OK.

What’s NOT OK, though, is the risk of that damage turning into a chronic liver disease. 

The difference between an «oral steroid cycle that didn’t turn into a chronic issue» and an «oral steroid cycle that did» is complex, but one small compound plays a crucial role in it: glutathione.

Glutathione levels have been labeled as one of the most important factors in prevention of chronic liver diseases. It acts inside the cells, regulating their natural balance and basically «helping» them to survive the stress [3].

Just so you understand how powerful and important glutathione actually is: 

  • Glutathione can save the liver after hardcore damage caused by prolonged alcohol intake [4];
  • Intravenous injections of glutathione are sometimes used to help people survive poisoning;
  • The FDA had to stop the production of NAC supplements since it’s actually labeled as a drug, not some herbal mix (but they’ve reversed the decision in 2022) [6]. 

In short, it’s one undeniably beneficial compound for your liver. And that’s exactly what you need to support your body on an oral steroid cycle. 

How NAC Works

If you wonder now, why not take glutathione itself, you’re asking the right question. 

Unfortunately, glutathione is not as bioavailable (less effective if you take it directly) and it costs 6 times more than NAC to produce. You COULD take glutathione supplements, and you actually CAN now, they’re finally out there, but they’re just more expensive and way less popular. 

10 years ago you could get glutathione exclusively via an intravenous injection, at a sky-high price, with a team of medical professionals. 

NAC is easier to make, goes through your digestive system without losing its effectiveness, and you can get it in nearly every Canadian pharmacy.

In simple terms, t’s the closest precursor to glutathione:

  1. You take a NAC pill;
  2. In a matter of 1-2 hours, cysteine connects to glutamine and glycine (naturally present in your body);
  3. And the result of this bond is — glutathione itself. 

So NAC is a convenient way to get precisely the same substance with less hassle. 

NAC Benefits for Steroid Cycle

You already know that NAC is one great thing, but this is what you get practically: 

  • Reduced oxidative stress (the one from all the oral anabolics) [5];
  • Removed toxins (all sorts, from mercury to steroid molecules «leftovers») [7];
  • Improves the liver markers and essentially the liver health itself [10].

NAC Benefits in Overall Health

Since we’re talking about the substance in terms of its effectiveness as a liver support compound during an oral steroid cycle, the three points above are — frankly speaking — all you need. 

However, NAC is in no way limited to just that. It’s not selective and doesn’t act exclusively in the liver. Here’s what else the substance can do:

  • Support your respiratory health (prevent lung diseases, reduce coughing);
  • Supports cellular health in general;
  • Increases magnesium;
  • Supports the immune system (to the point that it was widely discussed and proven to be an effective treatment during the that-one-disease-that-made-you-invest-in-a-home-gym-19 outbreak);
  • Stabilizes blood sugar (by acting as an antioxidant in the fat cells);
  • Improves fertility in BOTH men and women. 

There’s a whole separate list of all the beneficial things that NAC MAYBE does, though we’re not sure yet: 

  • May reduce depression symptoms;
  • May help in alcoholism and substance abuse treatment;
  • May improve heart health and reduces the risk of stroke;
  • May prevent kidney failure;
  • May be useful in flu treatment;
  • May help with elevated irritability in people with autism. 

In other words — NAC either is proven to do or can possibly do all the things that herbal mixes and holistic stuff claims to be able to accomplish.

NAC Drawbacks

It’s a good compound, but we’re not here to praise it and leave you in awe. Of course it has drawbacks as well. 

NAC Smells Really, Really Bad

The substance has sulfur in it (naturally, it’s a sulfur-based thing, not some weird chemical experiment). And sulfur doesn’t smell good.

The closest analog from real life is — rotten eggs. 

Some manufacturers mask the smell. It’s 100% possible with a tablet form. Some just don’t care. Depending on your preferred brand, you may or may not have this problem.

It may have side effects. 

Generally, NAC is well-tolerated. It's OK for kids, for adults, and even for animals. However, a smooth ride is not guaranteed. You may be one of those who’ll experience: 

  • Diarrhea;
  • Vomiting;
  • Nausea;
  • Rashes;
  • And upset stomach. 

Those side effects are rare, though. But you still should know they exist. 

It may have more side effects that we don’t know about yet. 

Just as there are studies that explore potential benefits of NAC, there are papers that focus on potential dangers and downsides. The two primary areas of concern are the brain and the heart: 

  1. NAC might have an adverse effect on the blood-brain-barrier. At least it did in a study on mice [8];
  2. It may increase the amount of homocysteine, a natural substance that is associated with adverse effects on heart health [9];
  3. It may cause anhedonia — at least it’s reported anecdotally;
  4. In addition, NAC is not actually recommended to people with bleeding issues or asthma.

Does it mean that you «trade» liver health for brain and heart health? Hell no. These potential risks are vastly outnumbered by all the proven benefits. 

However, you still should think twice and maybe talk to your doc about NAC use if you have any of the issues listed above. In fact, if you have heart health issues, you should not take oral anabolic steroids in the first place — so we hope you don’t.

How to Take NAC for Liver Support on Cycle

The short answer is — orally, like any other pill, in accordance with the instruction on the label. And here’s a detailed breakdown on all the specifics of NAC and steroids: 

Dosage: 600 mg for minimal support, 1200 mg to 1800 mg on cycle. Doses up to 3000 mg were used in studies with no adverse effects reported.

When to take: every day, separated in equal administrations throughout the day.

When to start: on your very first day of taking orals.

When to stop: when you’re done with both your cycle and the PCT (though you can take NAC non-stop, some people run it for years).

Before or after taking orals: doesn’t matter, the two don’t interact at all and minutes of difference don’t affect neither NAC’s, nor the steroid’s effectiveness.

At the end of the day, there’s not much difference between taking NAC for liver support on cycle and taking it for any other reason. It’s not some specific medicine that requires precise dosing, strict protocol, or anything. It’s a way to replenish your natural liver support substances [11].

Final Word

NAC is probably the best liver support thing out there when it comes to helping your liver out in dealing with some major stress factor, like a bulking cycle with orals. It’s been in use in the bodybuilding community for decades, and rightfully so. 

Does it smell like sh!t? Yes. But it gets the job done.

And if you remember the old-school egg protein, this smell should bring back memories. So focus on making your oral anabolic cycle actually worth it, and let NAC take care of all the damage. In a stack with TUDCA, UDCA, Liv.52 or any other supplement, it will work even better.

NAC liver support on oral steroid cycle cheat sheet


  1. WebMD N-Acetyl Cysteine (Nac) - Uses, Side Effects, and More [];
  2. Hepatic effects of 17 alpha-alkylated anabolic-androgenic steroids [];
  3. Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study [];
  4. N-Acetylcysteine Improves Liver Function in Patients with Non-Alcoholic Fatty Liver Disease [];
  5. Drug-Induced Liver Injury: Clinical Evidence of N-Acetyl Cysteine Protective Effects [];
  6. FDA Final Guidance on Enforcement Discretion for Certain NAC Products [];
  7. Long term N-acetylcysteine administration rescues liver steatosis via endoplasmic reticulum stress with unfolded protein response in mice [];
  8. Long term N-acetylcysteine administration rescues liver steatosis via endoplasmic reticulum stress with unfolded protein response in mice [];
  9. A Systematic Review on the Protective Effect of N-Acetyl Cysteine Against Diabetes-Associated Cardiovascular Complications [];
  10. Effects of oral N-acetylcysteine combined with oral prednisolone on idiopathic sudden sensorineural hearing loss [];
  11. Role of N-acetylcysteine in non-acetaminophen-related acute liver failure: an updated meta-analysis and systematic review [].